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#
# For a description of the syntax of this configuration file,
# see the file kconfig-language.txt in the NuttX tools repository.
#
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 field
widths.
config LIBC_FLOATINGPOINT
bool "Enable floating point in printf"
default n
---help---
By default, floating point
support in printf, sscanf, etc. is disabled.
config LIBC_LONG_LONG
bool "Enable long long support in printf"
default y if !DEFAULT_SMALL
default n if DEFAULT_SMALL
---help---
Enables support for long long formats in printf, sscanf, etc. is
enabled. This is enabled by default but if you are trying to
reduce the FLASH footprint, then disabling this feature is one
option. The FLASH saves comes not from disabling the long long
formats, but rather from omitting the large long long arithmetic
libraries that will be drawn into the build if long long support
is enabled.
config LIBC_IOCTL_VARIADIC
bool "Enable variadic ioctl()"
default n
---help---
By default, NuttX implements the "old style," three-parameter,
ioctl() interface with this function prototype:
int ioctl(int fd, int req, unsigned long arg);
That function is implemented as part of the VFS. If
LIBC_IOCTL_VARIADIC is selected, then an additional compatibility
layer will be provided in the C library. The enabled, then function
prototype will become:
int ioctl(int fd, int req, ...);
The ioctl() is not controlled by any standard so it is really
arbitrary which format you used. You may select the variadic
function prototype with this option. That will slightly increase
code size and ioctl() processing time. It will not support a
variable number of arguments and it still always expects to see a
third argument of type 'unsigned long'. The only benefit of this
alternative function signature is that it may provide greater
compatibility if you are porting code from other platforms that use
the variadic ioctl() function.
WARNING: Use of this option could cause subtle system errors is
the third argument is omitted or if the sizeof the thread argument
is anything other than sizeof (unsigned long). Most small integers
will be promoted to 'int'. The following assertion appears in ioctl():
DEBUGASSERT(sizeof(int) == sizeof(unsigned long) &&
sizeof(FAR void *) == sizeof(unsigned long));
Do not enable this option if the above is not true. 32-bit ARM
should pass this test with all three types having sizeof(type) == 4
bytes. 'float' should also be tested. But 'long long' and 'double'
are out of the question! Don't event try to pass them.
And what will happen if no third argument is passed? In most cases,
this should just result in a garbage value for arg. But you may
discover cases where something worse happens!
config LIB_RAND_ORDER
int "Order of the random number generate"
default 1
range 1 3
---help---
The order of the random number generator. 1=fast but very bad random
numbers, 3=slow but very good random numbers.
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_HAVE_SYMTAB
bool "Have symbol table"
default n if BUILD_KERNEL
default y if !BUILD_KERNEL
---help---
If you have a system symbol table, then you must select this
option in order to use it. Symbol tables are required in most
cases in order to like executable programs to the base code.
if EXECFUNCS_HAVE_SYMTAB
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 # EXECFUNCS_HAVE_SYMTAB
endif # LIBC_EXECFUNCS
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
depends on !ARCH_ADDRENV
---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 LIBC_TMPDIR
string "Temporary file directory"
default "/tmp"
depends on FS_WRITABLE
---help---
If a write-able file system is selected, this string will be
provided to specify the full path to a directory where temporary
files can be created. This would be a good application of RAM disk:
To provide temporary storage for application data.
config LIBC_MAX_TMPFILE
int "Maximum size of a temporary file path"
default 32
depends on FS_WRITABLE
---help---
If a write-able file system is selected, then temporary file may be
supported at the path provided by LIBC_TMPDIR. The tmpnam() interface
keeps a static copy of this last filename produced; this value is the
maximum size of that last filename. This size is the size of the full
file path.
config ARCH_LOWPUTC
bool "Low-level console output"
default "y"
---help---
architecture supports low-level, boot time console output
config LIBC_LOCALTIME
bool "localtime API call support"
default "n"
depends on !DISABLE_ENVIRON
---help---
localtime API call support
Logic currently depends on file system support with, at a minimum, these
files in the zoneinfo directory: GMT and posixrules. An additional
timezone file is required for any additional, local time zone(s) and the
environment variable TZ must be set to the name of that timezone file
when tzset() is called.
See https://www.iana.org/time-zones . See also apps/system/zoneinfo
which provides a framework for incorporating the TZ database into a
NuttX build.
if LIBC_LOCALTIME
config LIBC_TZ_MAX_TIMES
int "Maximum number of times in timezone"
default 370
---help---
Timezone files with more than this number of times will not be usedi
(tmecnt).
Warning: Some files in IANA TZ database include many times. The current
posixrules file, for example, has timecnt = 236. The value of
TX_MAX_ITMES in the tzfile.h header file on my Linux system is 370, the
default used here. You may want to reduce this value for a smaller
footprint.
config LIBC_TZ_MAX_TYPES
int "Maximum number of TZ types"
default 20
---help---
Maximum number of local time types. You may want to reduce this value
for a smaller footprint.
config LIBC_TZDIR
string "zoneinfo directory path"
default "/etc/zoneinfo"
---help---
This is the full path to the location where the TZ database is expected
to be found.
endif
config TIME_EXTENDED
bool "Add day of week, year support"
default "n"
depends on !LIBC_LOCALTIME
---help---
Selecting TIME_EXTENDED adds tm_wday, tm_yday and tm_isdst
to the tm struct. This allows integration with 3rd party libraries
that expect the tm struct to contain these members.
Note: tm_isdst is always 0
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 buses, 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 is selected, 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 # MEMCPY_VIK
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 # ARCH_OPTIMIZED_FUNCTIONS
config LIBC_NETDB
bool
default n
menuconfig NETDB_HOSTFILE
bool "Network host file support"
default n
depends on FS_READABLE
select LIBC_NETDB
---help---
Enable network host table look ups via gethostbyname() and
gethostbyaddr().
if NETDB_HOSTFILE
config NETDB_HOSTCONF_PATH
string "Path to host configuration file"
default "/etc/hosts"
config NETDB_MAX_ALTNAMES
int "Max number of alternate host names"
default 4
config NETDB_BUFSIZE
int "gethostname() buffer size"
default 128
endif # NETDB_HOSTFILE
config NETDB_DNSCLIENT
bool "DNS Name resolution"
default n
depends on NET && NET_UDP
select LIBC_NETDB
---help---
Enable support for the name resolution; Enable network host
resolution via gethostbyname().
if NETDB_DNSCLIENT
config NETDB_DNSCLIENT_ENTRIES
int "Number of DNS resolver entries"
default 0 if DEFAULT_SMALL
default 8 if !DEFAULT_SMALL
range 0 255
---help---
Number of cached DNS resolver entries. Default: 8. Zero disables
all cached name resolutions.
Disabling the DNS cache means that each access call to
gethostbyname() will result in a new DNS network query. If
CONFIG_NETDB_DNSCLIENT_ENTRIES is non-zero, then entries will be
cached and if the name mapping can be found in that cache, the
network query can be avoid. Of course, this is only useful if you
query the same name often and if the IP address of the name is
stable. If the IP address can change, then cachin DNS address
might have undesirable side-effects (see help for
CONFIG_NETDB_DNSCLIENT_LIFESEC).
config NETDB_DNSCLIENT_NAMESIZE
int "Max size of a cached hostname"
default 32
---help---
The size of a hostname string in the DNS resolver cache is fixed.
This setting provides the maximum size of a hostname. Names longer
than this will be aliased! Default: 32
config NETDB_DNSCLIENT_LIFESEC
int "Life of a DNS cache entry (seconds)"
default 3600
---help---
Cached entries in the name resolution cache older than this will not
be used. Default: 1 hour. Zero means that entries will not expire.
Small values of CONFIG_NETDB_DNSCLIENT_LIFESEC may result in more
network DNS queries; larger values can make a host unreachable for
the entire duration of the timeout value. This might happen, for
example, if the remote host was assigned a different IP address by
a DHCP server.
config NETDB_DNSCLIENT_MAXRESPONSE
int "Max response size"
default 96
---help---
This setting determines the maximum size of response message that
can be received by the DNS resolver. The default is 96 but may
need to be larger on enterprise networks (perhaps 176).
choice
prompt "DNS server address type"
default NETDB_DNSSERVER_NOADDR
config NETDB_DNSSERVER_NOADDR
bool "No default DNS server address"
config NETDB_DNSSERVER_IPv4
bool "IPv4 DNS server address"
depends on NET_IPv4
config NETDB_DNSSERVER_IPv6
bool "IPv6 DNS server address"
depends on NET_IPv6
endchoice # DNS server address type
config NETDB_DNSSERVER_IPv4ADDR
hex "Target IPv4 address"
default 0x0a000001
depends on NETDB_DNSSERVER_IPv4
---help---
Default DNS server IPv4 address in host byte order. Default value
10.0.0.0.1. This may be changed via dns_setserver().
if NETDB_DNSSERVER_IPv6
config NETDB_DNSSERVER_IPv6ADDR_1
hex "[0]"
default 0xfc00
range 0x0 0xffff
---help---
This is the default IP address of the DNS server. This is a 16-bit
integer value in host order. Each of the eight values forming the
full IPv6 address must be specified individually. This is the first
of the 8-values. The default for all eight values is fc00::1.
config NETDB_DNSSERVER_IPv6ADDR_2
hex "[1]"
default 0x0000
range 0x0 0xffff
---help---
This is the default IP address of the DNS server. This is a 16-bit
integer value in host order. Each of the eight values forming the
full IPv6 address must be specified individually. This is the second
of the 8-values. The default for all eight values is fc00::1.
config NETDB_DNSSERVER_IPv6ADDR_3
hex "[2]"
default 0x0000
range 0x0 0xffff
---help---
This is the default IP address of the DNS server. This is a 16-bit
integer value in host order. Each of the eight values forming the
full IPv6 address must be specified individually. This is the third
of the 8-values. The default for all eight values is fc00::1.
config NETDB_DNSSERVER_IPv6ADDR_4
hex "[3]"
default 0x0000
range 0x0 0xffff
---help---
This is the default IP address of the DNS server. This is a 16-bit
integer value in host order. Each of the eight values forming the
full IPv6 address must be specified individually. This is the fourth
of the 8-values. The default for all eight values is fc00::1.
config NETDB_DNSSERVER_IPv6ADDR_5
hex "[4]"
default 0x0000
range 0x0 0xffff
---help---
This is the default IP address of the DNS server. This is a 16-bit
integer value in host order. Each of the eight values forming the
full IPv6 address must be specified individually. This is the fifth
of the 8-values. The default for all eight values is fc00::1.
config NETDB_DNSSERVER_IPv6ADDR_6
hex "[5]"
default 0x0000
range 0x0 0xffff
---help---
This is the default IP address of the DNS server. This is a 16-bit
integer value in host order. Each of the eight values forming the
full IPv6 address must be specified individually. This is the sixth
of the 8-values. The default for all eight values is fc00::1.
config NETDB_DNSSERVER_IPv6ADDR_7
hex "[6]"
default 0x0000
range 0x0 0xffff
---help---
This is the default IP address of the DNS server. This is a 16-bit
integer value in host order. Each of the eight values forming the
full IPv6 address must be specified individually. This is the seventh
of the 8-values. The default for all eight values is fc00::1.
config NETDB_DNSSERVER_IPv6ADDR_8
hex "[7]"
default 0x0001
range 0x0 0xffff
---help---
This is the default IP address of the DNS server. This is a 16-bit
integer value in host order. Each of the eight values forming the
full IPv6 address must be specified individually. This is the last
of the 8-values. The default for all eight values is fc00::1.
endif # NETDB_DNSSERVER_IPv6
endif # NETDB_DNSCLIENT
comment "Non-standard Library Support"
if BUILD_PROTECTED || BUILD_KERNEL
config LIB_USRWORK
bool "User mode worker thread"
default n
depends on !DISABLE_SIGNALS
---help---
User space work queues can also be made available for deferred
processing in the NuttX kernel build.
if LIB_USRWORK
config LIB_USRWORKPRIORITY
int "User mode priority worker thread priority"
default 100
---help---
The execution priority of the user-mode priority worker thread. Default: 100
config LIB_USRWORKPERIOD
int "User mode worker thread period"
default 100000
---help---
How often the lower priority worker thread checks for work in units
of microseconds. Default: 100*1000 (100 MS).
config LIB_USRWORKSTACKSIZE
int "User mode worker thread stack size"
default 2048
---help---
The stack size allocated for the lower priority worker thread. Default: 2K.
endif # LIB_USRWORK
endif # BUILD_PROTECTED || BUILD_KERNEL
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.). 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.
Some special encoding may be required to multiplex these two classes
of data.
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.
config LIB_SLCDCODEC
bool "Segment LCD CODEC"
default n
---help---
In NuttX, a character-oriented, segment LCD (SLCD) driver is simply
a character device that may have an (optional) encoding/decoding
layer on the data provided to the SLCD driver. The application may
provide simple text data (alphabetic, numeric, and punctuaction) or
control characters (enter, control-C, etc.). However, in addition,
most SLCDs support actions that cannot be represented as text data.
Such actions include things like cursor controls (home, up arrow,
page down, etc.) and other special functions (e.g., blinking). Some
special encoding may be required to multiplex these two classes of
data.
This option enables the functions that implement the encoding and
decoding of SLCD data. These are the interfaces prototyped in
include/nuttx/lcd/slcd_codec.h. While not correctly a part of the C
library, it is included here because the encoding side of this
interface must be accessible by end user programs.
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