NuttX TODO List (Last updated January 6, 2008)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
(6) Task/Scheduler (sched/)
(1) Dynamic loader (N/A)
(2) Memory Managment (mm/)
(1) Signals (sched/, arch/)
(1) pthreads (sched/)
(1) C++ Support
(11) Network (net/, netutils/)
(2) USB (drivers/usbdev)
(3) Libraries (lib/)
(2) File system (fs/, drivers/)
(1) Pascal add-on (pcode/)
(2) Documentation (Documentation/)
(3) Build system
(0) Applications & Tests (examples/)
(1) ARM (arch/arm/)
(1) ARM/C5471 (arch/arm/src/c5471/)
(2) ARM/DM320 (arch/arm/src/dm320/)
(2) ARM/LPC214x (arch/arm/src/lpc214x/)
(4) pjrc-8052 / MCS51 (arch/pjrc-8051/)
(2) z80 (arch/z80/)
(4) z16 (arch/z16/)
o Task/Scheduler (sched/)
^^^^^^^^^^^^^^^^^^^^^^^
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.
Description: atexit() supports registration of one function called on exit().
Should task_delete() also cause atexit() function to be called?
Status: Open
Priority: Low, task_delete() is non-standard and its behavior is
unspecified.
Description: Implement sys/mman.h and functions
Status: Open
Priority: Low
Description: Implement sys/wait.h and functions. Consider implementing wait,
waitpid, waitid. At present, a parent has no information about
child tasks.
Status: Open
Priority: Low
Description: Implement priority inheritance
Status: Open
Priority: Medium, this is a good feature for realtime systems.
Description: Several APIs do not set errno. Need to review all APIs.
Status: Open
Priority: Medium, required for standard compliance (but makes the
code bigger)
o Dynamic Loader
^^^^^^^^^^^^^^
Description: At some point in the future, I intend to port the XFLAT
dynamic loader into NuttX (see http://xflat.sourceforge.net/).
That would allow NuttX to dynamically load and link
external code in a mounted filesystem.
Status: Open
Priority: Low, Nice feature and I might do it someday
o Memory Managment (mm/)
^^^^^^^^^^^^^^^^^^^^^^
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.
Status: Open
Priority: Medium/Low, a good feature to prevent memory leaks but would
have negative impact on memory usage and code size.
Description: Current logic adapts size_t for 16-bit address machines vs.
32-bit address machines. But a small memory option should also
be provided so that the small offset option can be used with
32-bit machines that have small RAM memories (like the lpc2148)
Status: Open
Priority: High, a good feature enhancement.
o Signals (sched/, arch/)
^^^^^^^^^^^^^^^^^^^^^^^
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.
o pthreads (sched/)
^^^^^^^^^^^^^^^^^
Description: pthread_cancel(): Should implement cancellation points and
pthread_testcancel()
Status: Open
Priority: Low, probably not that useful
o C++ Support
^^^^^^^^^^^
Description: Need to call static constructors
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 Network (net/, netutils/)
^^^^^^^^^^^^^^^^^^^^^^^^^
Description: Several of the netutils/ apps are untested. These include
uIP's netutils/smtp, dhcpd, resolv, webclient. Only minimal
testing of the others has been performed.
Status: Open
Priority: Medium, Important but not core NuttX functionality
Description: Should implement SOCK_RAW, SOCK_PACKET
Status: Open
Priority: Low
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.
Description: Sendoto() 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.
Description: uIP/Socket callback logic is not thread safe. This means that
a socket cannot be used concurrently by two threads. Minimal
fix: Add mutex to support exclusion for protection.
Status: Open
Priority: Low. The currently socket design cannot be use concurrently
by threads with out a major redesign. The feature is not
of great value since the use model for multi-thread sockets
is not common. Adding mutex support would only mask the
underlying issue.
Description: IPv6 support is incomplete
Status: Open
Priority: Medium
Description: Incoming UDP broadcast should only be accepted if listening on
INADDR_ANY(?)
Status: Open
Priority: Low
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
Description: Need to standardize collection of statistics from network
drivers. examples/nsh ifconfig command should present
statistics.
Status: Open
Priority: Low
Description: Outgoing packets are dropped and overwritten by ARP packets
if the destination IP has not been mapped to a MAC. Could
improve send() performance by explicitly performing ARP before
sending the packet.
Status: Open
Priority: Medium
Description: Port PPP support from http://contiki.cvs.sourceforge.net/contiki/contiki-2.x/backyard/core/net/ppp/
Status: Open
Priority: Low
o USB (drivers/usbdev)
^^^^^^^^^^^^^^^^^^^^
Description: Implement USB device support
Status: Open
Priority: High
Description: Implement USB bulk / serial device support
Status: Open
Priority: High
o Libraries (lib/)
^^^^^^^^^^^^^^^^
Description: sscanf() and lib_vsprintf() do not support floating point
values.
Status: Open
Priority: Low
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
Description: There are two different copies of getenv(): One in
sched/env_getenv.c and one in lib/lib_getenv(). Keep one.
Status: Open
Priority: Low
o File system (fs/, drivers/)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
Description: Add chmod(), truncate().
Status: Open
Priority: Low
Description: FAT32: long file names
Status: Open
Priority: Medium
o Pascal Add-On (pcode/)
^^^^^^^^^^^^^^^^^^^^^^
Description: Need a test to verify execution of P-Code from files.
Need APIs to verify execution of P-Code from memory buffer.
Status: Open
Priority: Medium
o Documentation (Documentation/)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Description: Document driver/ logic
Status: Open
Priority: Low
Description: Document C-library APIs
Status: Open
Priority: Low
o Build system
^^^^^^^^^^^^
Description: Some names under arch are still incorrect. These should be
processor architecture names: pjrc-8051 should be 805x
Status: Open
Priority: Low
Description: configs/pjrc-8051 should be configs/pjrc-87c52
Status: Open
Priority: Low
Description: Dependencies do not work correctly under configs/<board>/src
(same as arch/<arch>/src/board). Seems to be worse using SDCC.
Status: Open
Priority: Medium (maybe higher for z80 target)
o Applications & Tests (examples/)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
o ARM (arch/arm/)
^^^^^^^^^^^^^^^
Description: Add option to use a separate stack for interrupt handling. At
present, each interrupt executes on top of the user stack
allocation making each user stack allocation larger than needed.
Status: Open
Priority: Medium
o ARM/C5471 (arch/arm/src/c5471/)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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/)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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
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/LPC214x (arch/arm/src/lpc214x/)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Description: Finish bringup
Status: Open
Priority: High
Description: Add MMC and USB support
Status: Open
Priority: Mediam
o pjrc-8052 / MCS51 (arch/pjrc-8051/)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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.
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
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
examples/ostest/barrier.c around lines 53 and 74
examples/ostest/sighand.c at 225 and 244
driver/serial.c in usleep calls around 347 and 354
Status: Open
Priority: Medium
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 z80 (arch/z80)
^^^^^^^^^^^^^^^
Description: The Has the same problems with interger 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
Priority: See pjrc-8051
Description: The simulated 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.
o z16 (arch/z16)
^^^^^^^^^^^^^^^^
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.
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.
Description: The system delays do not appear to be correct with the
examples/ostest/timedmqueue.c test.
Status: Open
Priority: Medium-High
Description: At present, the z16f port does not run properly when CONFIG_DEBUG
is disabled. I have not determined the cause for this -- it
may be an issue with optimization?? Or clock setup??
Status: Open
Priority: Medium-High
