#
# For a description of the syntax of this configuration file,
# see misc/tools/kconfig-language.txt.
#
comment "Standard C Library Options"
config STDIO_BUFFER_SIZE
int "C STDIO buffer size"
default 64
---help---
Size of buffers using within the C buffered I/O interfaces.
(printf, putchar, fwrite, etc.).
config STDIO_LINEBUFFER
bool "STDIO line buffering"
default y
---help---
Flush buffer I/O whenever a newline character is found in
the output data stream.
config NUNGET_CHARS
int "Number unget() characters"
default 2
---help---
Number of characters that can be buffered by ungetc() (Only if NFILE_STREAMS > 0)
config LIB_HOMEDIR
string "Home directory"
default "/"
depends on !DISABLE_ENVIRON
---help---
The home directory to use with operations like such as 'cd ~'
source libc/math/Kconfig
config NOPRINTF_FIELDWIDTH
bool "Disable sprintf support fieldwidth"
default n
---help---
sprintf-related logic is a
little smaller if we do not support fieldwidthes
config LIBC_FLOATINGPOINT
bool "Enable floating point in printf"
default n
---help---
By default, floating point
support in printf, sscanf, etc. is disabled.
choice
prompt "Newline Options"
default EOL_IS_EITHER_CRLF
---help---
This selection determines the line terminating character that is used.
Some environments may return CR as end-of-line, others LF, and others
both. If not specified, the default is either CR or LF (but not both)
as the line terminating charactor.
config EOL_IS_CR
bool "EOL is CR"
config EOL_IS_LF
bool "EOL is LF"
config EOL_IS_BOTH_CRLF
bool "EOL is CR and LF"
config EOL_IS_EITHER_CRLF
bool "EOL is CR or LF"
endchoice
config LIBC_EXECFUNCS
bool "Enable exec[l|v] / posix_spawn() Support"
default n
depends on !BINFMT_DISABLE
---help---
Enable support for the exec[l|v] family of functions that can be
used to start other programs, terminating the current program and
the posix_spawn() familty of functions that can be used start other
programs without terminating the current program. The typical
usage of the exec[l|v] functions is (1) first call vfork() to create
a new thread, then (2) call exec[l|v] to replace the new thread with
a program from the file system.
NOTE 1: This two step process start is completely unnecessary in
NuttX and is provided only for compatibily with Unix systems. These
functions are essentially just wrapper functions that (1) call the
non-standard binfmt function 'exec', and then (2) exit(0). Since
the new thread will be terminated by the exec[l|v] call, it really
served no purpose other than to suport Unix compatility.
The posix_spawn() functions do not have this inefficiency.
NOTE 2: Support for exec[l|v] and posix_spawn() is conditional
because they require additional support for symbol tables that
will not be available in the typical system.
if LIBC_EXECFUNCS
config EXECFUNCS_SYMTAB
string "Symbol table used by exec[l|v]"
default "g_symtab"
---help---
The exec[l|v] and posix_spawn() functions are wrapper functions that
call the non-standard binfmt function 'exec'). The binfmt
function 'exec' needs to have (1) a symbol table that provides the
list of symbols exported by the base code, and (2) the number of
symbols in that table. This selection provides the name of that
symbol table.
config EXECFUNCS_NSYMBOLS
int "Number of Symbols in the Table"
default 0
---help---
The exec[l|v] and posix_spawn() functions are wrapper functions that
call the non-standard binfmt function 'exec'). The binfmt
function 'exec' needs to have (1) a symbol table that provides the
list of symbols exported by the base code, and (2) the number of
symbols in that table. This selection provides the number of
symbols in the symbol table.
endif
config POSIX_SPAWN_PROXY_STACKSIZE
int "Spawn Stack Size"
default 1024
---help---
If posix_spawn[p]() and task_spawn() use I/O redirection options,
they will require an intermediary/proxy task to muck with the file
descriptors. This configuration item specifies the stack size
used for the proxy. Default: 1024 bytes.
config TASK_SPAWN_DEFAULT_STACKSIZE
int "Default task_spawn Stack Size"
default 2048
---help---
The actual size to use for the child task's stack can be set with
task_spawnattr_setstacksize(). This value specifies the default
stack size to use if task_spawnattr_setstacksize() is not used.
Default: 2048.
config LIBC_STRERROR
bool "Enable strerror"
default n
---help---
strerror() is useful because it decodes 'errno' values into a human readable
strings. But it can also require a lot of memory. If this option is selected,
strerror() will still exist in the build but it will not decode error values.
This option should be used by other logic to decide if it should use strerror()
or not. For example, the NSH application will not use strerror() if this
option is not selected; perror() will not use strerror() is this option is not
selected (see also NSH_STRERROR).
config LIBC_STRERROR_SHORT
bool "Use short error descriptions in strerror()"
default n
depends on LIBC_STRERROR
---help---
If this option is selected, then strerror() will use a shortened string when
it decodes the error. Specifically, strerror() is simply use the string that
is the common name for the error. For example, the 'errno' value of 2 will
produce the string "No such file or directory" is LIBC_STRERROR_SHORT
is not defined but the string "ENOENT" is LIBC_STRERROR_SHORT is defined.
config LIBC_PERROR_STDOUT
bool "perror() to stdout"
default n
---help---
POSIX requires that perror() provide its output on stderr. This option may
be defined, however, to provide perror() output that is serialized with
other stdout messages.
config ARCH_LOWPUTC
bool "Low-level console output"
default "y"
---help---
architecture supports low-level, boot time console output
config LIB_SENDFILE_BUFSIZE
int "sendfile() buffer size"
default 512
---help---
Size of the I/O buffer to allocate in sendfile(). Default: 512b
config ARCH_ROMGETC
bool "Support for ROM string access"
default n
---help---
In Harvard architectures, data accesses and instruction accesses
occur on different busses, perhaps concurrently. All data accesses
are performed on the data bus unless special machine instructions
are used to read data from the instruction address space. Also, in
the typical MCU, the available SRAM data memory is much smaller that
the non-volatile FLASH instruction memory. So if the application
requires many constant strings, the only practical solution may be
to store those constant strings in FLASH memory where they can only
be accessed using architecture-specific machine instructions.
If ARCH_ROMGETC is defined, then the architecture logic must export
the function up_romgetc(). up_romgetc() will simply read one byte
of data from the instruction space.
If ARCH_ROMGETC, certain C stdio functions are effected: (1) All
format strings in printf, fprintf, sprintf, etc. are assumed to lie
in FLASH (string arguments for %s are still assumed to reside in SRAM).
And (2), the string argument to puts and fputs is assumed to reside
in FLASH. Clearly, these assumptions may have to modified for the
particular needs of your environment. There is no "one-size-fits-all"
solution for this problem.
config ARCH_OPTIMIZED_FUNCTIONS
bool "Enable arch optimized functions"
default n
---help---
Allow for architecture optimized implementations of certain library
functions. Architecture-specific implementations can improve overall
system performance.
if ARCH_OPTIMIZED_FUNCTIONS
config ARCH_MEMCPY
bool "memcpy()"
default n
---help---
Select this option if the architecture provides an optimized version
of memcpy().
config MEMCPY_VIK
bool "Vik memcpy()"
default n
depends on !ARCH_MEMCPY
---help---
Select this option to use the optimized memcpy() function by Daniel Vik.
Select this option for improved performance at the expense of increased
size. See licensing information in the top-level COPYING file.
if MEMCPY_VIK
config MEMCPY_PRE_INC_PTRS
bool "Pre-increment pointers"
default n
---help---
Use pre-increment of pointers. Default is post increment of pointers.
config MEMCPY_INDEXED_COPY
bool "Array indexing"
default y
---help---
Copying data using array indexing. Using this option, disables the
MEMCPY_PRE_INC_PTRS option.
config MEMCPY_64BIT
bool "64-bit memcpy()"
default n
---help---
Compiles memcpy() for architectures that suppport 64-bit operations
efficiently.
endif
config ARCH_MEMCMP
bool "memcmp()"
default n
---help---
Select this option if the architecture provides an optimized version
of memcmp().
config ARCH_MEMMOVE
bool "memmove()"
default n
---help---
Select this option if the architecture provides an optimized version
of memmove().
config ARCH_MEMSET
bool "memset()"
default n
---help---
Select this option if the architecture provides an optimized version
of memset().
config MEMSET_OPTSPEED
bool "Optimize memset() for speed"
default n
depends on !ARCH_MEMSET
---help---
Select this option to use a version of memcpy() optimized for speed.
Default: memcpy() is optimized for size.
config MEMSET_64BIT
bool "64-bit memset()"
default n
depends on MEMSET_OPTSPEED
---help---
Compiles memset() for architectures that suppport 64-bit operations
efficiently.
config ARCH_STRCHR
bool "strchr()"
default n
---help---
Select this option if the architecture provides an optimized version
of strchr().
config ARCH_STRCMP
bool "strcmp()"
default n
---help---
Select this option if the architecture provides an optimized version
of strcmp().
config ARCH_STRCPY
bool "strcpy()"
default n
---help---
Select this option if the architecture provides an optimized version
of strcpy().
config ARCH_STRNCPY
bool "strncpy()"
default n
---help---
Select this option if the architecture provides an optimized version
of strncpy().
config ARCH_STRLEN
bool "strlen"
default n
---help---
Select this option if the architecture provides an optimized version
of strlen().
config ARCH_STRNLEN
bool "strlen()"
default n
---help---
Select this option if the architecture provides an optimized version
of strnlen().
config ARCH_BZERO
bool "bzero()"
default n
---help---
Select this option if the architecture provides an optimized version
of bzero().
endif
comment "Non-standard Library Support"
config SCHED_WORKQUEUE
bool "Enable worker thread"
default n
depends on !DISABLE_SIGNALS
---help---
Create a dedicated "worker" thread to handle delayed processing from interrupt
handlers. This feature is required for some drivers but, if there are no
complaints, can be safely disabled. The worker thread also performs
garbage collection -- completing any delayed memory deallocations from
interrupt handlers. If the worker thread is disabled, then that clean up will
be performed by the IDLE thread instead (which runs at the lowest of priority
and may not be appropriate if memory reclamation is of high priority).
if SCHED_WORKQUEUE
config SCHED_HPWORK
bool "High priority (kernel) worker thread"
default y
---help---
If SCHED_WORKQUEUE is defined, then a single, high priority work queue is
created by default. This high priority worker thread is intended to serve
as the "bottom half" for driver interrupt handling.
if SCHED_HPWORK
config SCHED_WORKPRIORITY
int "High priority worker thread priority"
default 192
---help---
The execution priority of the worker thread. Default: 192
config SCHED_WORKPERIOD
int "High priority worker thread period"
default 50000
---help---
How often the worker thread checks for work in units of microseconds.
Default: 50*1000 (50 MS).
config SCHED_WORKSTACKSIZE
int "High priority worker thread stack size"
default 2048
depends on SCHED_WORKQUEUE
---help---
The stack size allocated for the worker thread. Default: 2K.
config SCHED_LPWORK
bool "Low priority (kernel) worker thread"
default n
---help---
If SCHED_WORKQUEUE is defined, then a single work queue is created by
default. If SCHED_LPWORK is also defined then an additional, lower-
priority work queue will also be created. This lower priority work
queue is better suited for more extended processing (such as file system
clean-up operations)
if SCHED_LPWORK
config SCHED_LPWORKPRIORITY
int "Low priority worker thread priority"
default 50
---help---
The execution priority of the lopwer priority worker thread. Default: 192
config SCHED_LPWORKPERIOD
int "Low priority worker thread period"
default 50000
---help---
How often the lower priority worker thread checks for work in units
of microseconds. Default: 50*1000 (50 MS).
config SCHED_LPWORKSTACKSIZE
int "Low priority worker thread stack size"
default 2048
---help---
The stack size allocated for the lower priority worker thread. Default: 2K.
endif # SCHED_LPWORK
endif # SCHED_HPWORK
if NUTTX_KERNEL
config SCHED_USRWORK
bool "User mode worker thread"
default n
---help---
User space work queues can also be made available for deferred processing in the NuttX kernel build.
if SCHED_USRWORK
config SCHED_LPWORKPRIORITY
int "User mode priority worker thread priority"
default 50
---help---
The execution priority of the lopwer priority worker thread. Default: 192
config SCHED_LPWORKPERIOD
int "User mode worker thread period"
default 50000
---help---
How often the lower priority worker thread checks for work in units
of microseconds. Default: 50*1000 (50 MS).
config SCHED_LPWORKSTACKSIZE
int "User mode worker thread stack size"
default 2048
---help---
The stack size allocated for the lower priority worker thread. Default: 2K.
endif # SCHED_USRWORK
endif # NUTTX_KERNEL
endif # SCHED_WORKQUEUE
config LIB_KBDCODEC
bool "Keyboard CODEC"
default n
---help---
In NuttX, a keyboard/keypad driver is simply a character driver that
may have an (optional) encoding/decoding layer on the data returned
by the character driver. A keyboard may return simple text data
(alphabetic, numeric, and punctuaction) or control characters
(enter, control-C, etc.). We can think about this the normal
"in-band" keyboard data stream. However, in addition, most
keyboards support actions that cannot be represented as text data.
Such actions include things like cursor controls (home, up arrow,
page down, etc.), editing functions (insert, delete, etc.), volume
controls, (mute, volume up, etc.) and other special functions. We
can think about this as special, "out-of-band" keyboard commands.
In this case, some special encoding may be required to multiplex
the in-band text data and out-of-band command streams.
This option enables the functions that implement the encoding and
decoding of keyboard data. These are the interfaces prototyped in
include/nuttx/input/kbd_codec.h. While not correctly a part of
the C library, it is included here because the decoding side of this
interface must be accessible by end user programs.
