NuttX TODO List (Last updated September 16, 2012) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This file summarizes known NuttX bugs, limitations, inconsistencies with standards, things that could be improved, and ideas for enhancements. nuttx/ (6) Task/Scheduler (sched/) (1) On-demand paging (sched/) (1) Memory Managment (mm/) (2) Signals (sched/, arch/) (2) pthreads (sched/) (2) C++ Support (6) Binary loaders (binfmt/) (17) Network (net/, drivers/net) (4) USB (drivers/usbdev, drivers/usbhost) (11) Libraries (lib/) (9) File system/Generic drivers (fs/, drivers/) (5) Graphics subystem (graphics/) (1) Pascal add-on (pcode/) (1) Documentation (Documentation/) (6) Build system / Toolchains (5) Linux/Cywgin simulation (arch/sim) (6) ARM (arch/arm/) (1) ARM/C5471 (arch/arm/src/c5471/) (3) ARM/DM320 (arch/arm/src/dm320/) (2) ARM/i.MX (arch/arm/src/imx/) (3) ARM/LPC17xx (arch/arm/src/lpc17xx/) (7) ARM/LPC214x (arch/arm/src/lpc214x/) (2) ARM/LPC313x (arch/arm/src/lpc313x/) (0) ARM/LPC43x (arch/arm/src/lpc43xx/) (3) ARM/STR71x (arch/arm/src/str71x/) (3) ARM/LM3S6918 (arch/arm/src/lm3s/) (6) ARM/STM32 (arch/arm/src/stm32/) (3) AVR (arch/avr) (0) Intel x86 (arch/x86) (4) 8051 / MCS51 (arch/8051/) (3) MIPS/PIC32 (arch/mips) (1) Hitachi/Renesas SH-1 (arch/sh/src/sh1) (4) Renesas M16C/26 (arch/sh/src/m16c) (10) z80/z8/ez80 (arch/z80/) (8) z16 (arch/z16/) (1) mc68hc1x (arch/hc) apps/ (5) Network Utilities (apps/netutils/) (4) NuttShell (NSH) (apps/nshlib) (1) System libraries apps/system (apps/system) (5) Other Applications & Tests (apps/examples/) o Task/Scheduler (sched/) ^^^^^^^^^^^^^^^^^^^^^^^ Title: CHILD PTHREAD TERMINATION Description: When a tasks exits, shouldn't all of its child pthreads also be terminated? Status: Open Priority: Medium, required for good emulation of process/pthread model. Title: MMAN.H Description: Implement sys/mman.h and functions Status: Open Priority: Low Title: WAIT.H Description: Implement sys/wait.h and functions. Consider implementing wait, waitpid, waitid. At present, a parent has no information about child tasks. Update: A simple but usable version of waitpid() has been included. This version is not compliant with all specifications and can be enabled with CONFIG_SCHED_WAITPID. Status: Open Priority: Low Title: MISSING ERRNO SETTINGS Description: Several APIs do not set errno. Need to review all APIs. Update: These are being fixed as they are encountered. There is no accounting of how many interfaces have this problem. Status: Open Priority: Medium, required for standard compliance (but makes the code bigger) Title: TICKLESS OS Description: On a side note, I have thought about a tick-less timer for the OS for a long time. Basically we could replace the periodic system timer interrupt with a one-shot interval timer programmed for the next interesting event time. That is one way to both reduce the timer interrupt overhead and also to increase the accuracy of delays. Current timer processing is in sched/sched_processtimer.c: 1) Calls clock_timer() which just increments a counter (the system timer -- basically "up-time"). This is only used when code asks for the current time. In a tickless OS, some substitute answer for the question "What time is it?" would need to be developed. You could use an RTC? Or maybe logic that gets the time until the next interval expiration and computes the current time. The solution is not too difficult, but depends on a hardware solution. 2) Calls wd_timer() which handles the link list of ordered events: Each timer event is saved with the delta time to the next event in the list. So an interval timer would be perfect to implement this. 3) sched_process_timeslice(). Then there is round-robin time-slicing. Status: Open Priority: Low Title: posix_spawn() Description: This would be a good interface to add to NuttX. It is really just a re-packaging of the existing, non-standard NuttX exec() function. Status: Open Priority: Medium low. o On-demand paging (sched/) ^^^^^^^^^^^^^^^^^^^^^^^^^ Title: ON-DEMAND PAGE INCOMPLETE Description: On-demand paging has recently been incorporated into the RTOS. The design of this feature is described here: http://www.nuttx.org/NuttXDemandPaging.html. As of this writing, the basic feature implementation is complete and much of the logic has been verified. The test harness for the feature exists only for the NXP LPC3131 (see configs/ea3131/pgnsh and locked directories). There are some limitations of this testing so I still cannot say that the feature is fully functional. Status: Open Priority: Medium-Low o Other core OS logic ^^^^^^^^^^^^^^^^^^^ Title: GET_ENVIRON_PTR() Description: get_environ_ptr() (sched/sched_getenvironptr.c) is not implemented. The representation of the the environment strings selected for NutX is not compatible with the operation. Some significant re-design would be required to implement this funcion and that effort is thought to be not worth the result. Status: Open Priority: Low -- There is no plan to implement this. Title: TIMER_GETOVERRUN() Description: timer_getoverrun() (sched/timer_getoverrun.c) is not implemented. Status: Open Priority: Low -- There is no plan to implement this. o Memory Managment (mm/) ^^^^^^^^^^^^^^^^^^^^^^ Title: FREE MEMORY ON TASK EXIT Description: Add an option to free all memory allocated by a task when the task exits. This is probably not be worth the overhead for a deeply embedded system. There would be complexities with this implementation as well because often one task allocates memory and then passes the memory to another: The task that "owns" the memory may not be the same as the task that allocated the memory. Update. From the NuttX forum: ...there is a good reason why task A should never delete task B. That is because you will strand memory resources. Another feature lacking in most flat address space RTOSs is automatic memory clean-up when a task exits. That behavior just comes for free in a process-based OS like Linux: Each process has its own heap and when you tear down the process environment, you naturally destroy the heap too. But RTOSs have only a single, shared heap. I have spent some time thinking about how you could clean up memory required by a task when a task exits. It is not so simple. It is not as simple as just keeping memory allocated by a thread in a list then freeing the list of allocations when the task exists. It is not that simple because you don't know how the memory is being used. For example, if task A allocates memory that is used by task B, then when task A exits, you would not want to free that memory needed by task B. In a process-based system, you would have to explicitly map shared memory (with reference counting) in order to share memory. So the life of shared memory in that environment is easily managed. I have thought that the way that this could be solved in NuttX would be: (1) add links and reference counts to all memory allocated by a thread. This would increase the memory allocation overhead! (2) Keep the list head in the TCB, and (3) extend mmap() and munmap() to include the shared memory operations (which would only manage the reference counting and the life of the allocation). Then what about pthreads? Memory should not be freed until the last pthread in the group exists. That could be done with an additional reference count on the whole allocated memory list (just as streams and file descriptors are now shared and persist until the last pthread exits). I think that would work but to me is very unattractive and inconsistent with the NuttX "small footprint" objective. ... Other issues: - Memory free time would go up because you would have to remove the memory from that list in free(). - There are special cases inside the RTOS itself. For example, if task A creates task B, then initial memory allocations for task B are created by task A. Some special allocators would be required to keep this memory on the correct list (or on no list at all). Status: Open Priority: Medium/Low, a good feature to prevent memory leaks but would have negative impact on memory usage and code size. o Signals (sched/, arch/) ^^^^^^^^^^^^^^^^^^^^^^^ Title: STANDARD SIGNALS Description: 'Standard' signals and signal actions are not supported. (e.g., SIGINT, SIGCHLD, SIGSEGV, etc). Status: Open Priority: Low, required by standards but not so critical for an embedded system. Title: SIGEV_THREAD Description: sig_notify() logic does not support SIGEV_THREAD; structure struct sigevent does not provide required members sigev_notify_function or sigev_notify_attributes. Status: Low, there are alternative designs. However, these features are required by the POSIX standard. Priority: Low for now o pthreads (sched/) ^^^^^^^^^^^^^^^^^ Title: CANCELLATION POINTS Description: pthread_cancel(): Should implement cancellation points and pthread_testcancel() Status: Open Priority: Low, probably not that useful Title: PTHREAD_PRIO_PROTECT Description: Extended pthread_mutexattr_setprotocol() suport PTHREAD_PRIO_PROTECT: "When a thread owns one or more mutexes initialized with the PTHREAD_PRIO_PROTECT protocol, it shall execute at the higher of its priority or the highest of the priority ceilings of all the mutexes owned by this thread and initialized with this attribute, regardless of whether other threads are blocked on any of these mutexes or not. "While a thread is holding a mutex which has been initialized with the PTHREAD_PRIO_INHERIT or PTHREAD_PRIO_PROTECT protocol attributes, it shall not be subject to being moved to the tail of the scheduling queue at its priority in the event that its original priority is changed, such as by a call to sched_setparam(). Likewise, when a thread unlocks a mutex that has been initialized with the PTHREAD_PRIO_INHERIT or PTHREAD_PRIO_PROTECT protocol attributes, it shall not be subject to being moved to the tail of the scheduling queue at its priority in the event that its original priority is changed." Status: Open Priority: Low -- about zero, probably not that useful. Priority inheritance is already supported and is a much better solution. And it turns out that priority protection is just about as complex as priority inheritance. Exerpted from my post in a Linked-In discussion: "I started to implement this HLS/"PCP" semaphore in an RTOS that I work with (http://www.nuttx.org) and I discovered after doing the analysis and basic code framework that a complete solution for the case of a counting semaphore is still quite complex -- essentially as complex as is priority inheritance. "For example, suppose that a thread takes 3 different HLS semaphores A, B, and C. Suppose that they are prioritized in that order with A the lowest and C the highest. Suppose the thread takes 5 counts from A, 3 counts from B, and 2 counts from C. What priority should it run at? It would have to run at the priority of the highest priority semaphore C. This means that the RTOS must maintain internal information of the priority of every semaphore held by the thread. "Now suppose it releases one count on semaphore B. How does the RTOS know that it still holds 2 counts on B? With some complex internal data structure. The RTOS would have to maintain internal information about how many counts from each semaphore are held by each thread. "How does the RTOS know that it should not decrement the priority from the priority of C? Again, only with internal complexity. It would have to know the priority of every semaphore held by every thread. "Providing the HLS capability on a simple phread mutex would not be such quite such a complex job if you allow only one mutex per thread. However, the more general case seems almost as complex as priority inheritance. I decided that the implementation does not have value to me. I only wanted it for its reduced complexity; in all other ways I believe that it is the inferior solution. So I discarded a few hours of programming. Not a big loss from the experience I gained." o C++ Support ^^^^^^^^^^^ Title: USE OF SIZE_T IN NEW OPERATOR Description: The argument of the 'new' operators should take a type of size_t (see libxx/libxx_new.cxx and libxx/libxx_newa.cxx). But size_t has an unknown underlying. In the nuttx sys/types.h header file, size_t is typed as uint32_t (which is determined by architecture-specific logic). But the C++ compiler may believe that size_t is of a different type resulting in compilation errors in the operator. Using the underlying integer type Instead of size_t seems to resolve the compilation issues. Status: Kind of open. There is a workaround. Setting CONFIG_CXX_NEWLONG=y will define the operators with argument of type unsigned long; Setting CONFIG_CXX_NEWLONG=n will define the operators with argument of type unsigned int. But this is pretty ugly! A better solution would be to get ahold of the compilers definition of size_t. Priority: Low. Title: STATIC CONSTRUCTORS Description: Need to call static constructors Update: Static constructors are implemented for the STM32 F4 and this will provide the model for all solutions. Basically, if CONFIG_HAVE_CXXINITIALIZE=y is defined in the configuration, then board-specific code must provide the interface up_cxxinitialize(). up_cxxinitialize() is called from user_start() to initialize all static class instances. This TODO item probably has to stay open because this solution is only available on STM32 F4. Status: Open Priority: Low, depends on toolchain. Call to gcc's built-in static constructor logic will probably have to be performed by user logic in user_start(). o Binary loaders (binfmt/) ^^^^^^^^^^^^^^^^^^^^^^^^ Title: NXFLAT TESTS Description: Not all of the NXFLAT test under apps/examples/nxflat are working. Most simply do not compile yet. tests/mutex runs okay but outputs garbage on completion. Status: Open Priority: High Title: ARM UP_GETPICBASE() Description: The ARM up_getpicbase() does not seem to work. This means the some features like wdog's might not work in NXFLAT modules. Status: Open Priority: Medium-High Title: READ-ONLY DATA IN RAM Description: At present, all .rodata must be put into RAM. There is a tentative design change that might allow .rodata to be placed in FLASH (see Documentation/NuttXNxFlat.html). Status: Open Priority: Medium Title: GOT-RELATIVE FUNCTION POINTERS Description: If the function pointer to a statically defined function is taken, then GCC generates a relocation that cannot be handled by NXFLAT. There is a solution described in Documentataion/NuttXNxFlat.html, by that would require a compiler change (which we want to avoid). The simple workaround is to make such functions global in scope. Status: Open Priority: Low (probably will not fix) Title: USE A HASH INSTEAD OF A STRING IN SYMBOL TABLES Description: In the NXFLAT symbol tables... Using a 32-bit hash value instead of a string to identify a symbol should result in a smaller footprint. Status: Open Priority: Low Title: WINDOWS-BASED TOOLCHAIN BUILD Description: Windows build issue. Some of the configurations that use NXFLAT have the linker script specified like this: NXFLATLDFLAGS2 = $(NXFLATLDFLAGS1) -T$(TOPDIR)/binfmt/libnxflat/gnu-nxflat-gotoff.ld -no-check-sections That will not work for windows-based tools because they require Windows style paths. The solution is to do something like this: if ($(WINTOOL)y) NXFLATLDSCRIPT=${cygpath -w $(TOPDIR)/binfmt/libnxflat/gnu-nxflat-gotoff.ld} else NXFLATLDSCRIPT=$(TOPDIR)/binfmt/libnxflat/gnu-nxflat-gotoff.ld endif Then use NXFLATLDFLAGS2 = $(NXFLATLDFLAGS1) -T"$(NXFLATLDSCRIPT)" -no-check-sections Status: Open Priority: There are too many references like the above. They will have to get fixed as needed for Windows native tool builds. Title: TOOLCHAIN COMPATIBILITY PROBLEM Descripton: The older 4.3.3 compiler generates GOTOFF relocations to the constant strings, like: .L3: .word .LC0(GOTOFF) .word .LC1(GOTOFF) .word .LC2(GOTOFF) .word .LC3(GOTOFF) .word .LC4(GOTOFF) Where .LC0, LC1, LC2, LC3, and .LC4 are the labels correponding to strings in the .rodata.str1.1 section. One consequence of this is that .rodata must reside in D-Space since it will addressed relative to the GOT (see the section entitled "Read-Only Data in RAM" at http://nuttx.org/Documentation/NuttXNxFlat.html#limitations). The newer 4.6.3compiler generated PC relative relocations to the strings: .L2: .word .LC0-(.LPIC0+4) .word .LC1-(.LPIC1+4) .word .LC2-(.LPIC2+4) .word .LC3-(.LPIC4+4) .word .LC4-(.LPIC5+4) This is good and bad. This is good because it means that .rodata.str1.1 can now reside in FLASH with .text and can be accessed using PC-relative addressing. That can be accomplished by simply moving the .rodata from the .data section to the .text section in the linker script. (The NXFLAT linker script is located at nuttx/binfmt/libnxflat/gnu-nxflat.ld). This is bad because a lot of stuff may get broken an a lot of test will need to be done. One question that I have is does this apply to all kinds of .rodata? Or just to .rodata.str1.1? Status: Open. Many of the required changes are in place but, unfortunately, not enough go be fully functional. I think all of the I-Space-to-I-Space fixes are in place. However, the generated code also includes PC-relative references to .bss which just cannot be done. Priority: Medium. The workaround for now is to use the older, 4.3.3 OABI compiler. o Network (net/, drivers/net) ^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: SOCK_RAW/SOCK_PACKET Description: Should implement SOCK_RAW, SOCK_PACKET Status: Open Priority: Low Tile: MULTIPLE NETWORK INTERFACE SUPPORT Description: uIP polling issues / Multiple network interface support: (1) Current logic will not support multiple ethernet drivers. Each driver should poll on TCP connections connect on the network supported by the driver; UDP polling should respond with TX data only if the UDP packet is intended for the the network supported by the driver. (2) If there were multiple drivers, polling would occur at double the rate. Fix by using bound IP address in TCP connection (lipaddr) and verifying that it is in the subnet served by the driver. Status: Open Priority: Medium, The feature is not important, but it is important for NuttX to resolve the architectural issues. Title: SENDTO() AND MULTIPLE NETWORK INTERFACE SUPPORT Description: sendto() and multiple network interface support: When polled, would have to assure that the destination IP is on the subnet served by the polling driver. Status: Open Priority: Medium, The feature is not important, but it is important for NuttX to resolve the architectural issues. Title: IPv6 Description: IPv6 support is incomplete. Adam Dunkels has recently announced IPv6 support for uIP (currently only as part of Contiki). Those changes need to be ported to NuttX. Status: Open Priority: Medium Title: LISTENING FOR UDP BROADCASTS Description: Incoming UDP broadcast should only be accepted if listening on INADDR_ANY(?) Status: Open Priority: Low Title: READ-AHEAD THROTTLING Description: Read-ahead buffers capture incoming TCP data when no user thread is recv-ing the data. Should add some driver call to support throttling; when there is no listener for new data, the driver should be throttled. Perhaps the driver should disable RX interrupts when throttled and re-anable on each poll time. recvfrom would, of course, have to un-throttle. Status: Open Priority: Medium Title: STANDARDIZE ETHERNET DRIVER STATISTICS Description: Need to standardize collection of statistics from network drivers. apps/nshlib ifconfig command should present statistics. Status: Open Priority: Low Title: CONCURRENT TCP SEND OPERATIONS Description: At present, there cannot be two concurrent active TCP send operations in progress using the same socket. This is because the uIP ACK logic will support only one transfer at a time. The solution is simple: A mutex will be needed to make sure that each send that is started is able to be the exclusive sender until all of the data to be sent has been ACKed. Status: Open. There is some temporary logic to apps/nshlib that does this same fix and that temporary logic should be removed when send() is fixed. Priority: Medium-Low. This is an important issue for applications that send on the same TCP socket from multiple threads. Title: UDP READ-AHEAD? Description: TCP supports read-ahead buffering to handle the receipt of TCP/IP packets when there is no read() in place. Should such capability be useful for UDP? PRO: Would reduce packet loss and enable support for poll()/select(). CON: UDP is inherently lossy so why waste memory footprint? Status: Open Priority: Medium Title: NO POLL/SELECT ON UDP SOCKETS Description: poll()/select() is not implemented for UDP sockets because they do do not support read-ahead buffering. Therefore, there is never a case where you can read from a UDP socket without blocking. Status: Open, depends on UDP read-ahead support Priority: Medium Title: POLL/SELECT ON TCP SOCKETS NEEDS READ-AHEAD Description: poll()/select() only works for availability of buffered TCP read data (when read-ahead is enabled). The way writing is handled in uIP, all sockets must wait when send and cannot be notifiied when they can send without waiting. Status: Open, probably will not be fixed. Priority: Medium... this does effect porting of applications that expect different behavior from poll()/select() Title: SOCKETS DO NOT ALWAYS SUPPORT O_NONBLOCK Description: sockets do not support all modes for O_NONBLOCK. Sockets support only (1) TCP/IP non-blocking read operations when read-ahead buffering is enabled, and (2) TCP/IP accept() operations when TCP/IP connection backlog is enabled. Status: Open Priority: Low. Title: UNFINISHED CRYSTALLAN CS89X0 DRIVER Description: I started coding a CrystalLan CS89x0 driver (drivers/net/cs89x0.c), but never finished it. Status: Open Priority: Low unless you need it. Title: UNTESTED IGMPv2 Description: Support for client-side IGMPv2 multicast has been added but not yet tested (because I don't have a proper environment for multicast testing). There are most likely errors that need to be fixed at least in the receipt of multicast packets. In addition, an ethernet driver that needs to work with the IGMP logic will have to include additional support for multicast MAC address tables. Status: Open Priority: Low unless you need it. Title: INTERFACES TO LEAVE/JOIN IGMP MULTICAST GROUP Description: The interfaces used to leave/join IGMP multicast groups is non-standard. RFC3678 (IGMPv3) suggests ioctl() commands to do this (SIOCSIPMSFILTER) but also status that those APIs are historic. NuttX implements these ioctl commands, but is non-standard because: (1) It does not support IGMPv3, and (2) it looks up drivers by their device name (eg., "eth0") vs IP address. Linux uses setsockopt() to control multicast group membership using the IP_ADD_MEMBERSHIP and IP_DROP_MEMBERSHIP options. It also looks up drivers using IP addresses (It would require additional logic in NuttX to look up drivers by IP address). See http://tldp.org/HOWTO/Multicast-HOWTO-6.html Status: Open Priority: Medium. All standards compatibility is important to NuttX. However, most the mechanism for leaving and joining groups is hidden behind a wrapper function so that little of this incompatibilities need be exposed. Title: CONFIGURATIONS WITH TINY MTUS Description: Many configurations have the MTU (CONFIG_NET_BUFSIZE) set to very small numbers, less then the minimum MTU size that must be supported -- 576. This can cause problems in some networks: CONFIG_NET_BUFSIZE should be set to at least 576 in all defconfig files. The symptoms of using very small MTU sizes can be very strange. With Ubuntu 9.x and vsFtpd was that the total packet size did *not match* the packet size in the IP header. This then caused a TCP checksum failure and the packet was rejected. Status: Open Priority: Low... fix defconfig files as necessary. o USB (drivers/usbdev, drivers/usbhost) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: USB STORAGE DRIVER DELAYS Description: There is a workaround for a bug in drivers/usbdev/usbdev_storage.c. that involves delays. This needs to be redesigned to eliminate these delays. See logic conditioned on CONFIG_USBMSC_RACEWAR. Status: Open Priority: Medium Title: RTL8187 DRIVER IS UNFINISHED Description: misc/drivers/usbhost_rtl8187.c is a work in progress. There is no RTL8187 driver available yet. That is a work in progress it was abandoned because it depends on having an 802.11g stack. Status: Open Priority: Low (Unless you need RTL8187 support). Title: EP0 OUT CLASS DATA Description: There is no mechanism in place to handle EP0 OUT data transfers. There are two aspects to this problem, neither are easy to fix (only because of the number of drivers that would be impacted): 1. The class drivers only send EP0 write requests and these are only queued on EP0 IN by this drivers. There is never a read request queued on EP0 OUT. 2. But EP0 OUT data could be buffered in a buffer in the driver data structure. However, there is no method currently defined in the USB device interface to obtain the EP0 data. Updates: (1) The USB device-to-class interface as been extended so that EP0 OUT data can accompany the SETUP request sent to the class drivers. (2) The logic in the STM32 F4 OTG FS device driver has been extended to provide this data. Updates are still needed to other drivers. Status: Open Priority: High for class drivers that need EP0 data. For example, the CDC/ACM serial driver might need the line coding data (that data is not used currenly, but it might be). Title: USB HUB SUPPORT Description: Add support for USB hubs Status: Open Priority: Low/Unknown. This is a feature enhancement. o Libraries (lib/) ^^^^^^^^^^^^^^^^ Title: ENVIRON Description: The definition of environ in stdlib.h is bogus and will not work as it should. This is because the underlying representation of the environment is not an arry of pointers. Status: Open Priority: Medium Title: TERMIOS Description: Need some minimal termios support... at a minimum, enough to switch between raw and "normal" modes to support behavior like that needed for readline(). UPDATE: There is growing functionality in lib/termios/ and in the ioctl methods of several MCU serial drivers (stm32, lpc43, lpc17, pic32). However, as phrased, this bug cannot yet be closed since this "growing functionality" does not address all termios.h functionality and not all serial drivers support termios. Status: Open Priority: Low Title: DAYS OF THE WEEK Description: strftime() and other timing functions do not handle days of the week. Status: Open Priority: Low Title: RESETTING GETOPT() Description: There is an issue with the way that getopt() handles errors that return '?'. 1. Does getopt() reset its global variables after returning '?' so that it can be re-used? That would be required to support where the caller terminates parsing before reaching the last parameter. 2. Or is the client expected to continue parsing after getopt() returns '?' and parse until the final parameter? The current getopt() implementation only supports #2. Status: Open Priority: Low Title: FERROR() AND CLEARERR() Description: Not implemented: ferror() and clearerr() Status: Open Priority: Low Title: CONCURRENT STREAM READ/WRITE Description: NuttX only supports a single file pointer so reads and writes must be from the same position. This prohibits implementation of behavior like that required for fopen() with the "a+" mode. According to the fopen man page: "a+ Open for reading and appending (writing at end of file). The file is created if it does not exist. The initial file position for reading is at the beginning of the file, but output is always appended to the end of the file." At present, the single NuttX file pointer is positioned to the end of the file for both reading and writing. Status: Open Priority: Medium. This kind of operation is probably not very common in deeply embedded systems but is required by standards. Title: DIVIDE BY ZERO Description: This is bug 3468949 on the SourceForge website (submitted by Philipp Klaus Krause): "lib_strtod.c does contain divisions by zero in lines 70 and 96. AFAIK, unlike for Java, division by zero is not a reliable way to get infinity in C. AFAIK compilers are allowed e.g. give a compile- time error, and some, such as sdcc, do. AFAIK, C implementations are not even required to support infinity. In C99 the macro isinf() could replace the first use of division by zero. Unfortunately, the macro INFINITY from math.h probably can't replce the second division by zero, since it will result in a compile-time diagnostic, if the implementation does not support infinity." Status: Open Priority: Title: OLD dtoa NEEDS TO BE UPDATED Description: This implementation of dtoa in lib/stdio is old and will not work with some newer compilers. See http://patrakov.blogspot.com/2009/03/dont-use-old-dtoac.html Status: Open Priority: ?? Title: SYSLOG INTEGRATION Description: There are the beginnings of some system logging capabilities (see drivers/syslog, fs/fs_syslog.c, and lib/stdio/lib_librawprintf.c and lib_liblowprintf.c. For NuttX, SYSLOG is a concept and includes, extends, and replaces the legacy NuttX debug ouput. Some additional integration is required to formalized this. For example: o lib_rawprintf() shjould be renamed syslog(). o debug.h should be renamed syslog.h o And what about lib_lowprintf()? llsyslog? Status: Open Priority: Low -- more of a roadmap Title: FLOATING POINT FORMATS Description: Only the %f floating point format is supported. Others are accepted but treated like %f. Status: Open Priority: Medium (this might important to someone). Title: FLOATING POINT PRECISION Description: A fieldwidth and precision is required with the %f format. If %f is used with no format, than floating numbers will be printed with a precision of 0 (effectively presented as integers). Status: Open Priority: Medium (this might important to someone). o File system / Generic drivers (fs/, drivers/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ NOTE: The NXFFS file system has its own TODO list at nuttx/fs/nxffs/README.txt Title: CHMOD() AND TRUNCATE() Description: Implement chmod(), truncate(). Status: Open Priority: Low Title: CAN POLL SUPPORT Description: At present, the CAN driver does not support the poll() method. See drivers/can.c Status: Open Priority: Low Title: REMOVING PIPES AND FIFOS Description: There is no way to remove a FIFO or PIPE created in the pseudo filesystem. Once created, they persist indefinitely and cannot be unlinked. This is actually a more generic issue: unlink does not work for anything in the pseudo- filesystem. Status: Open, but partially resolved: pipe buffer is at least freed when there are not open references to the pipe/FIFO. Priority: Medium Title: ROMFS CHECKSUMS Description: The ROMFS file system does not verify checksums on either volume header on on the individual files. Status: Open Priority: Low. I have mixed feelings about if NuttX should pay a performance penalty for better data integrity. Title: SPI-BASED SD MULTIPLE BLOCK TRANSFERS Description: The simple SPI based MMCS/SD driver in fs/mmcsd does not yet handle multiple block transfers. Status: Open Priority: Medium-Low Title: READ-AHEAD/WRITE BUFFER UNTESTED Description: Block driver read-ahead buffer and write buffer support is implemented but not yet tested. Status: Open Priority: Low Title: SDIO-BASED SD READ-AHEAD/WRITE BUFFERING INCOMPLETE Description: The drivers/mmcsd/mmcsd_sdio.c driver has hooks in place to support read-ahead buffering and write buffering, but the logic is incomplete and untested. Status: Open Priority: Low Title: POLLHUP SUPPORT Description: All drivers that support the poll method should also report POLLHUP event when the driver is closedd. Status: Open Priority: Medium-Low Title: CONFIG_RAMLOG_CONSOLE DOES NOT WORK Description: When I enable CONFIG_RAMLOG_CONSOLE, the system does not come up propertly (using configuration stm3240g-eval/nsh2). The problem may be an assertion that is occuring before we have a console. Status: Open Priority: Medium o Graphics subystem (graphics/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ See also the NxWidgets TODO list file for related issues. Title: UNTESTED GRAPHICS APIS Description: Testing of all APIs is not complete. See http://nuttx.sourceforge.net/NXGraphicsSubsystem.html#testcoverage Status: Open Priority: Medium Title: ITALIC FONTS / NEGATIVE FONT OFFSETS Description: Font metric structure (in include/nuttx/nx/nxfont.h) should allow negative X offsets. Negative x-offsets are necessary for certain glyphs (and is very common in italic fonts). For example Eth, icircumflex, idieresis, and oslash should have offset=1 in the 40x49b font (these missing negative offsets are NOTE'ed in the font header files). Status: Open. The problem is that the x-offset is an unsigned bitfield in the current structure. Priority: Low. Title: RAW WINDOW AUTORAISE Description: Auto-raise only applies to NXTK windows. Shouldn't it also apply to raw windows as well? Status: Open Priority: Low Title: AUTO-RAISE DISABLED Description: Auto-raise is currently disabled in NX multi-server mode. The reason is complex: - Most touchscreen controls send touch data a high rates - In multi-server mode, touch events get queued in a message queue. - The logic that receives the messages performs the auto-raise. But it can do stupid things after the first auto-raise as it opperates on the stale data in the message queue. I am thinking that auto-raise ought to be removed from NuttX and moved out into a graphics layer (like NxWM) that knows more about the appropriate context to do the autoraise. Status: Open Priority: Medium low Title: IMPROVED NXCONSOLE FONT CACHING Description: Now each NxConsole instance has its own private font cache whose size is determined by CONFIG_NXCONSOLE_MXCHARS. If there are multiple NxConsole instances using the same font, each will have a separate font cache. This is inefficient and wasteful of memory: Each NxConsole instance should share a common font cache. Status: Open Priority: Medium. Not important for day-to-day testing but would be a critical improvement if NxConsole were to be used in a product. o Pascal Add-On (pcode/) ^^^^^^^^^^^^^^^^^^^^^^ Title: P-CODES IN MEMORY UNTESTED Description: Need APIs to verify execution of P-Code from memory buffer. Status: Open Priority: Low Title: SMALLER LOADER AND OBJECT FORMAT Description: Loader and object format may be too large for some small memory systems. Consider ways to reduce memory footprint. Status: Open Priority: Medium o Documentation (Documentation/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: DOCUMENT APIS USABLE FROM INTERRUPT HANDLERS Description: Need to document which APIs can be used in interrupt handlers (like mq_send and sem_post) and which cannot. Status: Open Priority: Low o Build system ^^^^^^^^^^^^ Title: NUTTX CONFIGURATION TOOL Description: Need a NuttX configuration tool. The number of configuration settings has become quite large and difficult to manage manually. Update: This task is essentially completed. But probably not for all platforms and all features. When do we know that the the features is complete and that we can switch to exclusive use of the tool? Status: Open Priority: Medium-low Title: NATIVE WINDOWS BUILD Description: At present, NuttX builds only under Linux or Cygwin. Investigate the possibility of a native Windows build using something like the GNUWin32 tools (coreutils+make+grep+sed+uname). Status: Open Priority: Low Title: WINDOWS DEPENDENCY GENERATION Description: Dependency generation is currently disabled when a Windows native toolchain is used. I think that the only issue is that all of the Windows dependencies needed to be quoted in the Make.dep files. Status: Open Priority: Low -- unless some dependency-related build issues is discovered. Title: SETENV.H Description: Logic in most setenv.sh files can create the following problem on many platforms: $ . ./setenv.sh basename: invalid option -- 'b' Try `basename --help' for more information. The problem is that $0 is the current running shell which may include a dash in front: $ echo $0 -bash But often is just /bin/bash (and the problem does not occur. The fix is: -if [ "$(basename $0)" = "setenv.sh" ]; then +if [ "$_" = "$0" ] ; then Status: Open Priority: Low. Use of setenv.sh is optional and most platforms do not have this problem. Scripts will be fixed one-at-a-time as is appropropriate. Title: MAKE EXPORT LIMITATIONS Description: The top-level Makefile 'export' target that will bundle up all of the NuttX libraries, header files, and the startup object into an export-able tarball. This target uses the tools/mkexport.sh script. Issues: 1. This script assumes the host archiver ar may not be appropriate for non-GCC toolchains 2. For the kernel build, the user libraries should be built into some libuser.a. The list of user libraries would have to accepted with some new argument, perhaps -u. Status: Open Priority: Low. Title: KERNEL BUILD MODE ISSUES - GRAPHICS/NSH PARTITIONING. Description: In the kernel build mode (where NuttX is built as a monlithic kernel and user code must trap into the protected kernel via syscalls), the single user mode cannot be supported. In this built configuration, only the multiple user mode can be supported with the NX server residing inside of the kernel space. In this case, most of the user end functions in graphics/nxmu must be moved to lib/nx and those functions must be built into libuser.a to be linked with the user-space code. A similar issue exists in NSH that uses some internal OS interfaces that would not be available in a kernel build (such as foreach_task, foreach_mountpoint, etc.). Status: Open Priority: Low -- the kernel build configuration is not fully fielded yet. o Linux/Cywgin simulation (arch/sim) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: SIMULATED SERIAL DRIVER Description: The simulated serial driver has some odd behavior. It will stall for a long time on reads when the C stdio buffers are being refilled. This only effects the behavior of things like fgetc(). Workaround: Set CONFIG_STDIO_BUFFER_SIZE=0, suppressing all C buffered I/O. Status: Open Priority: Low (because the simulator is only a test/development platform) Title: SIMULATOR NETWORKING SUPPORT Description: I never did get networking to work on the sim Linux target. On Linux, it tries to use the tap device (/dev/net/tun) to emulate an Ethernet NIC, but I never got it correctly integrated with the NuttX networking. NOTE: On Cygwin, the build uses the Cygwin WPCAP library and is, at least, partially functional (it has never been rigorously tested). Status: Open Priority: Low (unless you want to test networking features on the simulation). Title: ROUND-ROBIN SCHEDULING IN THE SIMULATOR Description: Since the simulation is not pre-emptible, you can't use round-robin scheduling (no time slicing). Currently, the timer interrupts are "faked" during IDLE loop processing and, as a result, there is no task pre-emption because there are no asynchrous events. This could probably be fixed if the "timer interrupt" were driver by Linux signals. NOTE: You would also have to implement irqsave() and irqrestore() to block and (conditionally) unblock the signal. Status: Open Priority: Low Title: NSH ISSUES ON THE SIMULATOR Descripion: The NSH example has some odd behaviors. Mult-tasking -- for example, execution of commands in background -- does not work normally. This is due to the fact that NSH uses the system standard input for the console. This means that the simulation is actually "frozen" all of the time when NSH is waiting for input and background commands never get the chance to run. Status: Open Priority: This will not be fixed. This is the normal behavior in the current design of the simulator. "Real" platforms will behave correctly because NSH will "sleep" when it waits for console inpu and other tasks can run freely. Title: DOUBLE COMMAND ECHO Description: In the NSH example, the host HOST echoes each command so after you you enter a command, the command is repeated on the next line. This is an artifact of the simulator only. Status: Open Priority: This will not be fixed. This is the normal behavior in the current design of the simulator. "Real" platforms will behave correctly. o ARM (arch/arm/) ^^^^^^^^^^^^^^^ Title: IMPROVED ARM INTERRUPT HANDLING Description: ARM interrupt handling performance could be improved in some ways. One easy way is to use a pointer to the context save area in current_regs instead of using up_copystate so much. see handling of 'current_regs" in arch/arm/src/armv7-m/* for examples of how this might be done. Status: Open Priority: Low Title: IMPROVED ARM INTERRUPT HANDLING Description: The ARM and Cortex-M3 interrupt handlers restores all regisers upon return. This could be improved as well: If there is no context switch, then the static registers need not be restored because they will not be modified by the called C code. (see arch/sh/src/sh1/sh1_vector.S for example) Status: Open Priority: Low Title: SVCALLS AND HARDFAULTS Description: The Cortex-M3 user context switch logic uses SVCall instructions. This user context switching time could be improved by eliminating the SVCalls and developing assembly language implementations of the context save and restore logic. Also, because interrupts are always disabled when the SVCall is executed, the SVC goes to the hard fault handler where it must be handled as a special case. I recall seeing some controls somewhere that will allow to suppress one hard fault. I don't recall the control, but something like this should be used before executing the SVCall so that it vectors directly to the SVC handler. Another, more standard option would be to use interrupt priority levels to control interrupts. In that case, (1) The SVC would be the highest priority interrupt (0), (2) irqsave() would set the interrupt mask level to just above that, and (2) irqrestore would restore the interrupt level. This would not be diffult, but does affect a lot of files! Status: Open Priority: Low Title: ARM INTERRUPTS AND USER MODE Description: The ARM interrupt handling (arch/arm/src/arm/up_vectors.S) returns using 'ldmia sp, {r0-r15}^' My understanding is that this works fine because everything is in kernel-mode. In an operating model where applications run in user mode and interrupts/traps run in kernel-mode, I think that there is a problem with this. This would like be a problem, for example, if for a kernel build where NuttX is built as a monolithic, protected kernel and user mode programs trap into the kernel. Status: Open Priority: Low until I get around to implementng security or kernel mode for the ARM platform. Title: CORTEX-M3 STACK OVERFLOW Description: There is bit bit logic inf up_fullcontextrestore() that executes on return from interrupts (and other context switches) that looks like: ldr r1, [r0, #(4*REG_CPSR)] /* Fetch the stored CPSR value */ msr cpsr, r1 /* Set the CPSR */ /* Now recover r0 and r1 */ ldr r0, [sp] ldr r1, [sp, #4] add sp, sp, #(2*4) /* Then return to the address at the stop of the stack, * destroying the stack frame */ ldr pc, [sp], #4 Under conditions of excessivley high interrupt conditions, many nested interrupts can oocur just after the 'msr cpsr' instruction. At that time, there are 4 bytes on the stack and, with each interrupt, the stack pointer may increment and possibly overflow. This can happen only under conditions of continuous interrupts. See this email thread: http://tech.groups.yahoo.com/group/nuttx/message/1261 On suggested change is: ldr r1, [r0, #(4*REG_CPSR)] /* Fetch the stored CPSR value */ msr spsr_cxsf, r1 /* Set the CPSR */ ldmia r0, {r0-r15}^ But this has not been proven to be a solution. Status: Open Priority: Low. The conditions of continous interrupts is really the problem. If your design needs continous interrupts like this, please try the above change and, please, submit a patch with the working fix. Title: KERNEL MODE ISSUES - HANDLERS Description: The is a design flaw in the ARM/Cortex trap handlers. Currently, they try to process the SYSCALL within the trap handler. That cannot work. There are two possibilities to fix this. 1) Just enable interrupts in the trap handler and make sure that that sufficient protection is in place to handler the nested interrupts, or 3) Return from the exception via a trampoline (such as is currently done for signal handlers). In the trampoline, the trap would processed in supervisor mode with interrupts enabled. Status: Open Priority: medium-high. o ARM/C5471 (arch/arm/src/c5471/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: UART RECONFIGURATION Description: UART re-configuration is untested and conditionally compiled out. Status: Open Priority: Medium. ttyS1 is not configured, but not used; ttyS0 is configured by the bootloader o ARM/DM320 (arch/arm/src/dm320/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: DEBUG ISSUES Description: config/ntos-dm320: It seems that when a lot of debug statements are added, the system no longer boots. This is suspected to be a stack problem: Making the stack bigger or removing arrays on the stack seems to fix the problem (might also be the bootloader overwriting memory) Status: Open Priority: Medium Title: USB DEVICE DRIVER UNTESTED Description: A USB device controller driver was added but has never been tested. Status: Open Priority: Medium Title: FRAMEBUFFER DRIVER UNTESTED Description: A framebuffer "driver" was added, however, it remains untested. Status: Open Priority: Medium Title: VIDEO ENCODER DRIVER Description: In order to use the framebuffer "driver" additional video encoder logic is required to setupt composite video output or to interface with an LCD. Status: Open Priority: Medium (high if you need to use the framebuffer driver) o ARM/i.MX (arch/arm/src/imx/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: PORT IS INCOMPLETE Description: The basic port of the i.MX1 architecuture was never finished. The port is incomplete (as of this writing, is still lacks a timer, interrupt decoding, USB, network) and untested. Status: Open Priority: Medium (high if you need i.MX1/L support) Title: SPI METHODS ARE NOT THREAD SAFE Description: SPI methods are not thread safe. Needs a semaphore to protect from re-entrancy. Status: Open Priority: Medium -- Will be very high if you do SPI access from multiple threads. o ARM/LPC17xx (arch/arm/src/lpc17xx/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: USB DMA INCOMPLETE Description: USB DMA not fully implemented. Partial logic is in place but it is fragmentary and bogus. (Leveraged from the lpc214x) Status: Open Priority: Low Title: SSP DRIVER IMPROVEMENTS Description: a) At present the SSP driver is polled. Should it be interrupt driven? Look at arch/arm/src/imx/imx_spi.c -- that is a good example of an interrupt driven SPI driver. Should be very easy to part that architecture to the LPC. b) See other SSP (SPI) driver issues listed under ARM/LPC214x. The LPC17xx driver is a port of the LPC214x driver and probably has the same issues. b) Other SSP driver improvements: Add support for multiple devices on the SSP bus, use DMA data transfers Status: Open Priority: Medium Title: NOKIA LCD DRIVER NONFUNCTIONAL Description: An LCD driver for the Olimex LPC1766STK has been developed. However, that driver is not yet functional on the board: The backlight comes on, but nothing is visible on the display. Status: Open Priority: Medium-Low (unless you need the display on the LPC1766STK!) o ARM/LPC214x (arch/arm/src/lpc214x/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: VECTOR INTERRUPTS Description: Should use Vector Interrupts Status: Open Priority: Low Title: USB DMA INCOMPLETE Description: USB DMA not fully implemented. Partial logic is in place but it is fragmentary and bogus. Status: Open Priority: Low Title: USB SERIAL DRIVER REPORTS WRONG ERROR Description: USB Serial Driver reports wrong error when opened before the USB is connected (reports EBADF instead of ENOTCONN) Status: Open Priority: Low Title: SPI DRIVER IMPROVEMENTS Description: At present the SPI driver is polled. Should it be interrupt driven? Look at arch/arm/src/imx/imx_spi.c -- that is a good example of an interrupt driven SPI driver. Should be very easy to part that architecture to the LPC. Status: Open Priority: Medium Title: SPI METHODS ARE NOT THREAD SAFE Description: SPI methods are not thread safe. Needs a semaphore to protect from re-entrancy. Status: Open Priority: Medium -- Will be very high if you do SPI access from multiple threads. Title: SPI DRIVER DELAYS Description: At present the SPI driver is polled -AND- there is a rather large, arbitrary, delay in one of the block access routines. The purpose of the delay is to avoid a race conditions. This begs for a re-design -OR- at a minimum, some optimiation of the delay time. Status: Open Priority: Medium Title: 2GB SD CARD ISSUES Desription: I am unable to initialize a 2Gb SanDisk microSD card (in adaptor) on the the mcu123 board. The card fails to accept CMD0. Doesn't seem like a software issue, but if anyone else sees the problem, I'd like to know. Related: Fixes were recently made for the SDIO-based MMC/SD driver to support 2Gb cards -- the blocksize was forced to 512 in all cases. The SPI- based driver may also have this problem (but I don't think this would have anything to do with CMD0). Status: Open Priority: Uncertain Title: USB BROKEN? Description: I tried to bring up the new configuration at configs/mcu123-214x/composite, and Linux failed to enumerate the device. I don't know if this is a problem with the lpc214x USB driver (bit rot), or due to recent changed (e.g., -r4359 is suspicious), or an incompatibility between the Composite driver and the LPC214x USB driver. It will take more work to find out which -- like checking if the other USB configurations are also broken. Status: Open Priority: It would be high if the LPC2148 were a current, main stream architecture. I am not aware of anyone using LPC2148 now so I think the priority has to be low. o ARM/LPC31xx (arch/arm/src/lpc31xx/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: PLATFORM-SPECIFIC LOGIC Description: arch/arm/src/lpc313x/lpc313x_spi.c contains logic that is specific to the Embedded Artist's ea3131 board. We need to abstract the assignment of SPI chip selects and logic SPI functions (like SPIDEV_FLASH). My thoughts are: - Remove lpc313x_spiselect and lpc313x_spistatus from lpc313x_internal.h - Remove configs/ea3131/src/up_spi.c - Add configurations CONFIG_LPC3131x_CSOUT1DEV, CONFIG_LPC3131x_CSOUT2DEV, and CONFIG_LPC3131x_CSOUT3DEV that maps the lpc313x SPI chip selects to SPIDEV_* values. - Change arch/arm/src/lpc313x/lpc313x_spi.c to use those configuration settings. Status: Open Priority: High if you want to use SPI on any board other than the ea3131. Title: SPI DRIVER Description: arch/arm/src/lpc313x/lpc313x_spi.c may or may not be functional. It was reported to be working, but I was unable to get it working with the Atmel at45dbxx serial FLASH driver. Status: Open Priority: High if you need to use SPI. o ARM/LPC43x (arch/arm/src/lpc43xx/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ o ARM/STR71x (arch/arm/src/str71x/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: UNVERIFIED MMC SUPPORT Description: Verify SPI driver and integrate with MMC support. This effort is stalled at the moment because the slot on the Olimex board only accepts MMC card; I have no MMC cards, only SD cards which won't fit into the slot. Status: Open Priority: Medium Title: NO USB DRIVER Description: Develop a USB driver and integrate with existing USB serial and storage class drivers. Status: Open Priority: Medium Title: SPI METHODS ARE NOT THREAD SAFE Description: SPI methods are not thread safe. Needs a semaphore to protect from re-entrancy. Status: Open Priority: Medium -- Will be very high if you do SPI access from multiple threads. o ARM/LM3S6918 (arch/arm/src/lm3s/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: I2C DRIVER Description: Still need to implement I2C Status: Open Priority: Low Title: SSI OVERRUNS Description: Should terminate SSI/SPI transfer if an Rx FIFO overrun occurs. Right now, if an Rx FIFO overrun occurs, the SSI driver hangs. Status: Open Priority: Medium, If the transfer is properly tuned, then there should not be any Rx FIFO overruns. Title: THTTPD BUGS Description: There are some lingering bugs in THTTPD, possibly race conditions. This is covered above under Network Utilities, but is duplicated here to point out that the LM3S suffers from this bug. Status: Open. UPDATE: I have found that increasing the size of the CGI program stack from 1024 to 2048 (on the LM3S) eliminates the problem. So the most likely cause is probably a stack overflow, not a hard sofware bug. Priority: Probably Low o ARM/STM32 (arch/arm/src/stm32/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: NOR FLASH DRIVER Description: NOR Flash driver with FTL layer to support a file system. Status: Open Priority: Low Title: USBSERIAL ISSUES Description A USB device-side driver is in place but not well tested. At present, the apps/examples/usbserial test sometimes fails. The situation that causes the failure is: - Host-side of the test started after the target side sends the first serial message. The general failure is as follows: - The target message pends in the endpoint packet memory - When the host-side of the test is stated, it correctly reads this pending data. - an EP correct transfer interrupt occurs and the next pending outgoing message is setup - But, the host never receives the next message If the host-side driver is started before the first target message is sent, the driver works fine. Status: Open Priority: Medium-High Title: FSMC EXTERNAL MEMORY UNTESTED Description: FSMC external memory support is untested Status: Open Priority: Low Title: DMA EXTENSIONS Description: DMA logic needs to be extended. DMA2, Channel 5, will not work because the DMA2 channels 4 & 5 share the same interrupt. Status: Open Priority: Low until someone needs DMA1, Channel 5 (ADC3, UART4_TX, TIM5_CH1, or TIM8_CH2). Title: UNFINISHED DRIVERS Description: The following drivers are incomplete: DAC. The following drivers are untested: DMA on the F4, CAN. Status: Open Priority: Medium Title: F4 SDIO MULTI-BLOCK TRANSFER FAILURES Description: If you use a large I/O buffer to access the file system, then the MMCSD driver will perform multiple block SD transfers. With DMA ON, this seems to result in CRC errors detected by the hardware during the transfer. Workaround: CONFIG_MMCSD_MULTIBLOCK_DISABLE=y. Status: Open Priority: Medium Title: DMA BOUNDARY CROSSING Description: I see this statement in the reference manual: "The burst configuration has to be selected in order to respect the AHB protocol, where bursts must not cross the 1 KB address boundary because the minimum address space that can be allocated to a single slave is 1 KB. This means that the 1 KB address boundary should not be crossed by a burst block transfer, otherwise an AHB error would be generated, that is not reported by the DMA registers." The implication is that there may be some unenforced alignment requirements for some DMAs. There is nothing in the DMA driver to prevent this now. Status: Open Priority: Low (I am not even sure if this is a problem yet). o AVR (arch/avr) ^^^^^^^^^^^^^^ Title: AMBER WEB SERVER UNTESTED Description: There is a port for the Amber Web Server ATMega128, however this is completely untested due to the lack to compatible, functional test equipment. Status: Open Priority: The priority might as well be low since there is nothing I can do about it anyway. Title: STRINGS IN RAM Description: Many printf-intensive examples (such as the OS test) cannot be executed on most AVR platforms. The reason is because these tests/examples generate a lot of string data. The build system currently places all string data in RAM and the string data can easily overflow the tiny SRAMs on these parts. A solution would be to put the string data into the more abundant FLASH memory, but this would require modification to the printf logic to access the strings from program memory. Status: Open Priority: Low. The AVR is probably not the architecuture that you want to use for extensive string operations. Title: SPI AND USB DRIVERS UNTESTED Description: An SPI driver and a USB device driver exist for the AT90USB (as well as a USB mass storage example). However, this configuration is not fully debugged as of the NuttX-6.5 release. Update 7/11: (1) The SPI/SD driver has been verified, however, (2) I believe that the current teensy/usbstorage configuration uses too much SRAM for the system to behave sanely. A lower memory footprint version of the mass storage driver will be required before this can be debugged Status: Open Priority: Medium-High. Title: AVR32 PORT IS NOT FULLY TESTED Description: A complete port for the AVR32 is provided and has been partially debugged. There may still be some issues with the serial port driver. Status: Open Priority: Medium o Intel x86 (arch/x86) ^^^^^^^^^^^^^^^^^^^^ o 8051 / MCS51 (arch/8051/) ^^^^^^^^^^^^^^^^^^^^^^^^^ Title: STACK OVERFLOWS DURING INTERRUPT HANDLING Description: Current status: - Basic OS task management seems OK - Fails when interrupts enabled. The stack pointer is around 0x6e before the failure occurs. It looks like some issue when the stack pointer moves from the directly to indirectly addressable region (0x80 boundary). - Work on the 8052 is temporarily on hold Status: Open Priority: Low, 8051 is a tough platform because of the tiny stack. Title: TIMER 0 AS SYSTEM TIMER Description: Use timer 0 as system timer. Timer 2 is needed for second UART. Logic is implemented, but there needs to be a system configuration to change the ticks-per-second value to match the timer interrupt rate Status: Open Priority: Low Title: OVERFLOWS DURING BUILD Description: During build, there are several integer overflows reported: sched/gmtime_r.c aroud lines 184 and 185 sched/clock_initialize.c at line 107 sched/pthread_create.c at 330 apps/examples/ostest/barrier.c around lines 53 and 74 apps/examples/ostest/sighand.c at 225 and 244 driver/serial.c in usleep calls around 347 and 354 Status: Open. Update: These were reviewed during the hcs12 port. The hcs12 also has 16-bit integer types (if -mshort is in the CFLAGS). I believe that the warnings in most of the above have been fixed but this has not been verified on this platform). Priority: Medium Title: DATA INITIALIZATION Description Global data is not being initialized. Logic like that of SDCCs crt0*.s needs to be incorporated into the system boot logic Status: Open Priority: Low -- only because there as so many other issues with 8051 o MIPS/PIC32(arch/mips) ^^^^^^^^^^^^^^^^^^^^^ Title: PIC32 USB DRIVER DOES NOT WORK WITH MASS STORAGE CLASS UPDATE: ** ONLY USING RAM DISK FOR EXPORTED VOLUME *** Description: The PIC32 USB driver either crashes or hangs when used with the mass storage class when trying to write files to the target storage device. This usually works with debug on, but does not work with debug OFF (implying some race condition?) Here are some details of what I see in debugging: 1. The USB MSC device completes processing of a read request and returns the read request to the driver. 2. Before the MSC device can even begin the wait for the next driver, many packets come in at interrupt level. The MSC device goes to sleep (on pthread_cond_wait) with all of the read buffers ready (16 in my test case). 3. The pthread_cond_wait() does not wake up. This implies a problem with pthread_con_wait(?). But in other cases, the MSC device does wake up, but then immediately crashes because its stack is bad. 4. If I force the pthread_cond_wait to wake up (by using pthread_cond_timedwait instead), then the thread wakes up and crashes with a bad stack. So far, I have no clue why this is failing. UPDATE: This bug was recorded using the PIC32 Ethernet Starter kit with a RAM disk (that board has no SD card slot). Howevever, using the USB mass storage device with the Mikroelektronika using a real SD card, there is no such problem -- the mass storage device seems quite stable. UPDATE: Hmmm.. retesting with the Mikroelectronka board shows problems again. I think that there are some subtle timing bugs whose effects can very from innocuous to severe. Status: Open Priority: Originally, High BUT reduced to very Low based on the UPDATED comments. Title: PIC32 USB MASS STORAGE DEVICE FAILS TO RE-CONNECT Description: Found using configuration configs/pic32mx7mmb/nsh. In this configuratin, the NSH 'msconn' command will connect the mass storage device to the host; the 'msdis' command will disconnect the device. The first 'msconn' works perfectly. However, when attempting to re-connect, the second 'msconn' command does not command properly: Windows reports an unrecognized device. Apparently, some state is being properly reset when the mass storage device is disconnected. Shouldn't be hard to fix. Status: Open Priority: Medium Title: POSSIBLE INTERRUPT CONTROL ISSUE Description: There is a kludge in the file arch/mips/src/common/up_idle.c. Basically, if there is nothing else going on in the IDLE loop, you have to disable then re-enable interrupts. Logically nothing changes, but if you don't do this interrupts will be be disabled in the IDLE loop which is a very bad thing to happen. Some odd behavior in the interrupt setup on the IDLE loop is not really a big concern, but what I do not understand is if this behavior is occurring on all threads after all context switches: Are interrupts always disabled until re-enabled? This requires some further investigation at some point; it may be nothing but may also be a symptom of some changes required to the interrupt return logic (perhaps some CP0 status hazard?) Status: Open Priority: Low. Puzzling and needs some investigation, but there there is no known misbehavior. o Hitachi/Renesas SH-1 (arch/sh/src/sh1) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: SH-1 IS UNUSABLE Description: There are instabilities that make the SH-1 port un-usable. The nature of these is not understood; the behavior is that certain SH-1 instructions stop working as advertised. I have seen the following examples: 412b jmp @r1 - Set a return address in PR, i.e., it behaved like 410b jsr @r1. Normally 412b works correctly, but in the failure condition, it reliably set the PR. 69F6 mov.l @r15+,r9 - wrote the value of R1 to @r15+. This behavior does not correspond to any known SH-1 instruction This could be a silicon problem, some pipeline issue that is not handled properly by the gcc 3.4.5 toolchain (which has very limit SH-1 support to begin with), or perhaps with the CMON debugger. At any rate, I have exhausted all of the energy that I am willing to put into this cool old processor for the time being. Update: This bug will probably never be addressed now. I just cleaned house and my old SH-1 was one of the things that went. Status: Open Priority: Low -- because the SH-1, SH7032, is very old and only of historical interest. o Renesas M16C/26 (arch/sh/src/m16c) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: M16C DOES NOT BUILD Description: The M16C target cannot be built. The GNU m16c-elf-ld link fails with the following message: m32c-elf-ld: BFD (GNU Binutils) 2.19 assertion fail /home/Owner/projects/nuttx/buildroot/toolchain_build_m32c/binutils-2.19/bfd/elf32-m32c.c:482 Where the reference line is: /* If the symbol is out of range for a 16-bit address, we must have allocated a plt entry. */ BFD_ASSERT (*plt_offset != (bfd_vma) -1); No workaround is known at this time. Status: Open Priority: High -- this is a show stopper for M16C. Title: M16C PORT UNTESTED Description: Coding of the initial port is complete, but is untested. Status: Open Priority: Low Title: NO SERIAL CONNECTOR Description: Serial drivers were developed for the M16C, however, the SKP16C26 StarterKit has no serial connectors. Status: Open Priority: Low Title: UNIMPLEMENTED M16C DRIVERS Description: Should implement SPI, I2C, Virual EEPROM, FLASH, RTC drivers Status: Open Priority: Medium o z80/z8/ez80 (arch/z80) ^^^^^^^^^^^^^^^^^^^^^^^ Title: SDCC INTEGER OVERFLOWS Description: The SDCC version the same problems with integer overflow during compilation as described for pjrc-8051. At typical cause is code like usleep(500*1000) which exceeds the range of a 16-bit integer. Status: See pjrc-8051. These have probably been fixed but have not yet been verified on these platforms. Priority: See pjrc-8051 Title: Z80 SIMULATED CONSOLE Description: The simulated Z80 serial console (configs/z80sim/src/z80_serial.c + driver/serial.c) does not work. This is because there are no interrupts in the simulation so there is never any serial traffic. Status: Open Priority: Low -- the simulated console is not critical path and the designs to solve the problem are complex. Title: ZDS-II LIBRARIAN WARNINGS Description: ZDS-II Librarian complains that the source for the .obj file is not in the library. Status: Open Priority: Low, thought to be cosmetic. I think this is a consequence of replacing vs. inserting the library. Title: ZDS-II COMPILER PROBLEMS Description: The ZDS-II compiler (version 4.10.1) fails with an internal error while compiler mm/mm_initialize. This has been reported as incident 81509. I have found the following workaround that I use to build for the time being: --- mm/mm_initialize.c.SAVE 2008-02-13 08:06:46.833857700 -0600 +++ mm/mm_initialize.c 2008-02-13 08:07:26.367608900 -0600 @@ -94,8 +94,11 @@ { int i; +#if 0 /* DO NOT CHECK IN */ CHECK_ALLOCNODE_SIZE; CHECK_FREENODE_SIZE; +#endif /* Set up global variables */ Status: Open Priority: High Title: EZ8 PRIORITY INTERRUPTS Description: Add support for prioritized ez8 interrupts. Currently logic supports only nominal interrupt priority. Status: Open Priority: Low Title: Z8ENCORE ONLY VERIFIED ON SIMULATOR Description: The z8Encore! port has only been verified on the ZDS-II instruction set simulator. Status: Open Priority: Medium Title: XTRS CLEAN Description: The XTRS target (configs/xtrs) has a clean problem. The clean rule removes .asm files. This works because there are no .asm files except in sub-directories that are provided from 'make clean' -- except for XTRS: It has a .asm file in its src/ directory that gets removed everytime clean is performd. Status: Open Priority: High if you happen to be working with XTRS. Title: SPI/I2C UNTESTED Description: A "generic" SPI and I2C drivers have been coded for the eZ80Acclaim! However, these remains untested since I have no SPI or I2C devices for the board (yet). Status: Open Priority: Med Title: SPI METHODS ARE NOT THREAD SAFE Description: SPI methods are not thread safe. Needs a semaphore to protect from re-entrancy. Status: Open Priority: Medium -- Will be very high if you do SPI access from multiple threads. Title: I2C UNTESTED Description: A "generic" I2C driver has been coded for the eZ8Encore! However, this remains untested since I have no I2C devices for the board (yet). Status: Open Priority: Med o z16 (arch/z16) ^^^^^^^^^^^^^^^^ Title: ZDS-II LIBRARIAN WARNINGS Description: ZDS-II Librarian complains that the source for the .obj file is not in the library. Status: Open Priority: Low, thought to be cosmetic. I think this is a consequence of replacing vs. inserting the library. Title: SERIAL DRIVER HANGS Description: When the interrupt-driven serial driver is used, the system hangs. This is because of TX ready (TRDE) interrupts that get lost while interrupts are disabled. The existing serial driver appears to be limited to hardware with a latching, level-sensitive TX ready interrupt. Status: Open Priority: Medium. A polled, write-only serial driver is used in the interim for system testing. Title: SYSTEM DELAYS Description: The system delays do not appear to be correct with the apps/examples/ostest/timedmqueue.c test. Status: Open Priority: Medium-High Title: PROBLEMS WHEN DEBUG DISABLED Description: At present, the z16f port does not run properly when CONFIG_DEBUG is disabled: The obvious symptom is that there is no printf() output. I have isolated with problem to errors in optimization. With -reduceopt on the command line, I can get the printf output. However, there are still errors in the compiled code -- specifically in sched/timer_create.c. I have submitted a bug report to ZiLOG for this (support incident 81400). You can see the status of the bug report (and lots more technical detail) here: http://support.zilog.com/support/incident/incident_support.asp?iIncidentId=81400&iSiteId=1&chLanguageCode=ENG Summary of ZiLOG analysis: "This is a ZNEO compiler problem. ... [a] workaround is to replace: if ( !timerid || (clockid != 0) ) By: if ((clockid != 0) || !timerid)" Status: Open Priority: Medium-High Title: PASCAL ADD-ON Description: The pascal add-on does not work with the z16f (that is configuration z16f2800100zcog/pashello). This appears to be another ZDS-II error: when executing the instruction SYSIO 0, WRITESTR a large case statement is executed. This involves a call into the ZiLOG runtime library to __uwcase(). __uwcase is passed a pointer to a structure containing jump information. The cause of the failure appears to be that the referenced switch data is bad. This is submited as ZiLOG support incident 81459. Summary of ZiLOG analysis: "This is a ZNEO run time library problem. One workaround is to replace the line 58 in uwcase.asm From: ADD R9,#4 ; Skip handler To: ADD R9,#2 ; Skip handler And add uwcase.asm to the project. If the customer does not want to modify uwcase.asm then the other workaround is to add a dummy case and make it same as default: case 0x8000: default: This will make sure that uwcase is not called but ulcase is called." Status: Open. Due to licensing issues, I cannot include the modified uwcase in the NuttX code base. Priority: Medium Title: USE SPOV Description: Add support to maintain SPOV in context switching. This improvement will provide protection against stack overflow and make a safer system solution. Status: Open Priority: Low Title: PRIORITIZED INTERRUPTS Description: Add support for prioritized interrupts. Currently logic supports only nominal interrupt priority. Status: Open Priority: Low Title: ZDS-II COMPILER PROBLEMS Description: The file drivers/mmcsd/mmcsd_sdio.c generates an internal compiler error like: mmcsd\mmcsd_sdio.c Internal Error(0503) On line 2504 of "MMCSD\MMCSD_SDIO.C" File , Args(562,46) Status: Open. Recommended workaround: remove mmcsd_sdio.c from drivers/mmcsd/Make.defs. There is no SDIO support for the Z16 anyway Priority: Low o mc68hc1x (arch/hc) ^^^^^^^^^^^^^^^^^^ Title: BANKED MODE Description: There is no script for building in banked mode (more correctly, there is a script, but logic inside the script has not yet been implemented). It would be necessary to implement banked mode to able to access more the 48K of FLASH. Status: Open. Priority: Medium/Low o Network Utilities (apps/netutils/) Title: UIP RESOLVER Description: One critical part of netutils/ apps is untested: The uIP resolver in netutils/resolv. The webclient code has been tested on host using gethosbyname(), but still depends on the untested resolve logic. Status: Open Priority: Medium, Important but not core NuttX functionality Title: PPP PORT Description: Port PPP support from http://contiki.cvs.sourceforge.net/contiki/contiki-2.x/backyard/core/net/ppp/ Status: Open Priority: Low Title: UNVERIFIED THTTPD FEATURES Description: Not all THTTPD features/options have been verified. In particular, there is no test case of a CGI program receiving POST input. Only the configuration of apps/examples/thttpd has been tested. Status: Open Priority: Medium Title: THE ARP ISSUES AGAIN Description: The first GET received by THTTPD is not responded to. Refreshing the page from the browser solves the problem and THTTPD works fine after thatg. I believe that this is the duplicate of another bug: "Outgoing [uIP] packets are dropped and overwritten by ARP packets if the destination IP has not been mapped to a MAC." Status: Open Priority: Medium Title: THTTPD WARNINGS Description: If the network is enabled, but THTTPD is not configured, it spews out lots of pointless warnings. This is kind of annoying and unprofessional; needs to be fixed someday. Status: Open. An annoyance, but not a real problem. Priority: Low o NuttShell (NSH) (apps/nshlib) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: WGET UNTESTED Description: The wget command has been incorporated into NSH, however it is still untested as of this writing (only because I have not had the correct network setup for the testing yet). Since wget depends on the also untest uIP resolv/ logic, it is like non-functional. Status: Open Priority: Med-High Title: IFCONFIG AND MULTIPLE NETWORK INTERFACES Descripton: The ifconfig command will not behave correctly if an interface is provided and there are multiple interfaces. It should only show status for the single interface on the command line; it will still show status for all interfaces. Status: Open Priority: Low (multiple network interfaces not fully supported yet anyway). Title: RUN NXFLAT PROGRAMS Description: Add support to NSH to run NXFLAT programs from a ROMFS file system Status: Open Priority: Low (enhancement) Title: ARP COMMAND Description: Add an ARP command so that we can see the contents of the ARP table. Status: Open Priority: Low (enhancement) o System libraries apps/system (apps/system) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: READLINE IMPLEMENTATION Description: readline implementation does not use C-buffered I/O, but rather talks to serial driver directly via read(). It includes VT-100 specific editting commands. A more generic readline() should be implemented using termios' tcsetattr() to put the serial driver into a "raw" mode. Status: Open Priority: Low (unless you are using mixed C-buffered I/O with readline and fgetc, for example). o Other Applications & Tests (apps/examples/) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Title: EXAMPLES/PIPE ON CYGWIN Description: The redirection test (part of examples/pipe) terminates incorrectly on the Cywgin-based simulation platform (but works fine on the Linux-based simulation platform). Status: Open Priority: Low Title: EXAMPLES/WGET UNTESTED Description: examples/wget is untested on the target (it has been tested on the host, but not in the target using the uIP resolv logic). Status: Open Priority: Med Title: EXAMPLES/SENDMAIL UNTESTED Description: examples/sendmail is untested on the target (it has been tested on the host, but not on the target). Status: Open Priority: Med Title: EXAMPLES/NX FONT CACHING Description: The font caching logic in examples/nx is incomplete. Fonts are added to the cache, but never removed. When the cache is full it stops rendering. This is not a problem for the examples/nx code because it uses so few fonts, but if the logic were leveraged for more general purposes, it would be a problem. Update: see examples/nxtext for some improved font cache handling. Status: Open Priority: Low. This is not really a problem becauses examples/nx works fine with its bogus font caching. Title: EXAMPLES/NXTEXT ARTIFACTS Description: examples/nxtext. Artifacts when the pop-up window is opened. There are some artifacts that appear in the upper left hand corner. These seems to be related to window creation. At tiny artifact would not be surprising (the initial window should like at (0,0) and be of size (1,1)), but sometimes the artifact is larger. Status: Open Priority: Medium.