# # For a description of the syntax of this configuration file, # see the file kconfig-language.txt in the NuttX tools repository. # menu "Program Execution Options" 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() family of functions that can be used to 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 compatibility 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 support Unix compatibility. 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 depends on !BUILD_KERNEL ---help--- If you have a system symbol table, then you may select this option in order to use it. Symbol tables are required in most cases in order to link executable programs to the base code. NOTE: This option only pre-initializes the system symbol table as defined by CONFIG_EXECFUNCS_SYMTAB_ARRAY and CONFIG_EXECFUNCS_NSYMBOLS_VAR. This is simply an optional, automatic initialization of the system symbol table. You would need to do this, for example, in in the kernel build were the first task must be run from a program on the file system. This option has no other effect. Optionally, you can always call binfmt_setsymtab() from your board-specific logic or, equivalently, call boardctl(BOARDIOC_APP_SYMTAB) from your application initialization logic. if EXECFUNCS_HAVE_SYMTAB config EXECFUNCS_SYMTAB_ARRAY string "Symbol table name 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_VAR string "Name of variable holding the number of symbols" default "g_nsymbols" ---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 an 'int' variable that contains the number of symbols in the symbol table. config EXECFUNCS_SYSTEM_SYMTAB bool "Generate and include system symbol table" default n ---help--- Generate symbol table which includes symbols for all available syscalls, libc and libm functions. It makes system significantly larger but actual applications can reuse maximum from the system image. The symbol table array is named g_symtab and variable holding number of exported symbols g_nsymbols. It matches expected defaults from entries above. But they can be changed and generated symbol table can be used as template by application. endif # EXECFUNCS_HAVE_SYMTAB endif # LIBC_EXECFUNCS config POSIX_SPAWN_DEFAULT_STACKSIZE int "Default task_spawn Stack Size" default DEFAULT_TASK_STACKSIZE ---help--- The actual size to use for the child task's stack can be set with posix_spawnattr_setstacksize(). This value specifies the default stack size to use if posix_spawnattr_setstacksize() is not used. Default: 2048. endmenu # Program Execution Options config LIBC_HOSTNAME string "Host name for this device" default "" ---help--- A unique name to identify device on the network config LIBC_OPEN_MAX int "OPEN_MAX for this device" default 256 ---help--- The maximum number of files that a process can have open at any time. Must not be less than _POSIX_OPEN_MAX.