diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/Kconfig | 45 | ||||
| -rw-r--r-- | arch/x86/kernel/setup.c | 16 |
2 files changed, 61 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index ac2fb0641a0..fbcb79bbafd 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1392,6 +1392,51 @@ config COMPAT_VDSO If unsure, say Y. +config CMDLINE_BOOL + bool "Built-in kernel command line" + default n + help + Allow for specifying boot arguments to the kernel at + build time. On some systems (e.g. embedded ones), it is + necessary or convenient to provide some or all of the + kernel boot arguments with the kernel itself (that is, + to not rely on the boot loader to provide them.) + + To compile command line arguments into the kernel, + set this option to 'Y', then fill in the + the boot arguments in CONFIG_CMDLINE. + + Systems with fully functional boot loaders (i.e. non-embedded) + should leave this option set to 'N'. + +config CMDLINE + string "Built-in kernel command string" + depends on CMDLINE_BOOL + default "" + help + Enter arguments here that should be compiled into the kernel + image and used at boot time. If the boot loader provides a + command line at boot time, it is appended to this string to + form the full kernel command line, when the system boots. + + However, you can use the CONFIG_CMDLINE_OVERRIDE option to + change this behavior. + + In most cases, the command line (whether built-in or provided + by the boot loader) should specify the device for the root + file system. + +config CMDLINE_OVERRIDE + bool "Built-in command line overrides boot loader arguments" + default n + depends on CMDLINE_BOOL + help + Set this option to 'Y' to have the kernel ignore the boot loader + command line, and use ONLY the built-in command line. + + This is used to work around broken boot loaders. This should + be set to 'N' under normal conditions. + endmenu config ARCH_ENABLE_MEMORY_HOTPLUG diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 68b48e3fbcb..2f31cddd27b 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -223,6 +223,9 @@ unsigned long saved_video_mode; #define RAMDISK_LOAD_FLAG 0x4000 static char __initdata command_line[COMMAND_LINE_SIZE]; +#ifdef CONFIG_CMDLINE_BOOL +static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE; +#endif #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE) struct edd edd; @@ -673,6 +676,19 @@ void __init setup_arch(char **cmdline_p) bss_resource.start = virt_to_phys(&__bss_start); bss_resource.end = virt_to_phys(&__bss_stop)-1; +#ifdef CONFIG_CMDLINE_BOOL +#ifdef CONFIG_CMDLINE_OVERRIDE + strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE); +#else + if (builtin_cmdline[0]) { + /* append boot loader cmdline to builtin */ + strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE); + strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE); + strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE); + } +#endif +#endif + strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE); *cmdline_p = command_line; |