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#
# For a description of the syntax of this configuration file,
# see misc/tools/kconfig-language.txt.
#
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 ~'
config HAVE_LIBM
bool "Architecture-specific libm.a"
default n
---help---
Architecture specific logic provides an implementation of libm.a
and a math.h header file that can be found at include/arch/math.h.
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.
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
config ARCH_MEMCMP
bool "memcmp"
default n
config ARCH_MEMMOVE
bool "memmove"
default n
config ARCH_MEMSET
bool "memset"
default n
config ARCH_STRCMP
bool "strcmp"
default n
config ARCH_STRCPY
bool "strcpy"
default n
config ARCH_STRNCPY
bool "strncpy"
default n
config ARCH_STRLEN
bool "strlen"
default n
config ARCH_STRNLEN
bool "strlen"
default n
config ARCH_BZERO
bool "bzero"
default n
endif
config ARCH_HEADER_FILES
bool "Customize header files"
default n
---help---
The architecture may provide custom versions of certain
standard header files
if ARCH_HEADER_FILES
config ARCH_STDBOOL_H
bool "stdbool.h"
default n
---help---
The stdbool.h header file can be found at nuttx/include/stdbool.h.
However, that header includes logic to redirect the inclusion of an
architecture specific header file like:
#ifdef CONFIG_ARCH_STDBOOL_H
# include <arch/stdbool.h>
#else
...
#endif
Recall that that include path, include/arch, is a symbolic link and
will refer to a version of stdbool.h at nuttx/arch/<architecture>/include/stdbool.h.
config ARCH_MATH_H
bool "math.h"
default n
---help---
There is also a re-directing version of math.h in the source tree.
However, it resides out-of-the-way at include/nuttx/math.h because it
conflicts too often with the system math.h. If ARCH_MATH_H=y is
defined, however, the top-level makefile will copy the redirecting
math.h header file from include/nuttx/math.h to include/math.h. math.h
will then include the architecture-specific version of math.h that you
must provide at nuttx/arch/>architecture</include/math.h.
#ifdef CONFIG_ARCH_MATH_H
# include <arch/math.h>
#endif
So for the architectures that define ARCH_MATH_H=y, include/math.h
will be the redirecting math.h header file; for the architectures
that don't select ARCH_MATH_H, the redirecting math.h header file
will stay out-of-the-way in include/nuttx/.
config ARCH_STDARG_H
bool "stdarg.h"
default n
---help---
There is also a redirecting version of stdarg.h in the source tree
as well. It also resides out-of-the-way at include/nuttx/stdarg.h.
This is because you should normally use your toolchain's stdarg.h
file. But sometimes, your toolchain's stdarg.h file may have other
header file dependencies and so may not be usable in the NuttX build
environment. In those cases, you may have to create a architecture-
specific stdarg.h header file at nuttx/arch/<architecture>/include/stdarg.h
If ARCH_STDARG_H=y is defined, the top-level makefile will copy the
re-directing stdarg.h header file from include/nuttx/stdarg.h to
include/stdarg.h. So for the architectures that cannot use their
toolchain's stdarg.h file, they can use this alternative by defining
ARCH_STDARG_H=y and providing. If ARCH_STDARG_H, is not defined, then
the stdarg.h header file will stay out-of-the-way in include/nuttx/.
endif
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