Most architectures have similar boot command line manipulation options. This patchs adds the definition in init/Kconfig, gated by CONFIG_HAVE_CMDLINE that the architectures can select to use them. CONFIG_CMDLINE_EXTEND is understood differently by architectures. For some of them it appends built-in CMDLINE to bootloader provided line. For others it appends the bootloader provided CMDLINE to the built-in one. To avoid confusion, this commit brings to different options: - CONFIG_CMDLINE_APPEND to append the built-in CMDLINE to the bootloader line. - CONFIG_CMDLINE_PREPEND to prepend the built-in CMDLINE in front of the bootloader line. For compatibility with existing architecture which uses CONFIG_OF, as OF has already been converted to generic cmdline, we keep CONFIG_CMDLINE_EXTEND as a synonym to CONFIG_CMDLINE_APPEND until arm, powerpc, riscv and sh architectures have been converted. A few differences are identified and will have to be taken into account when converting the architecture to generic cmdline: - riscv has CMDLINE_FALLBACK instead of CMDLINE_FROM_BOOTLOADER - Some architectures are using CONFIG_CMDLINE_OVERRIDE or CONFIG_CMDLINE_OVERWRITE instead of CONFIG_CMDLINE_FORCE. Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx> --- v3: - Comments from Will. - Remove CONFIG_CMDLINE_BOOL. Using CONFIG_CMDLINE != "" instead, like arm and powerpc. - Changed EXTEND to APPEND. Keep EXTEND for backward compatibility. --- include/linux/cmdline.h | 2 +- init/Kconfig | 52 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 53 insertions(+), 1 deletion(-) diff --git a/include/linux/cmdline.h b/include/linux/cmdline.h index dea87edd41be..38306c109041 100644 --- a/include/linux/cmdline.h +++ b/include/linux/cmdline.h @@ -36,7 +36,7 @@ static __always_inline void __cmdline_build(char *dst, const char *src, size_t l cmdline_strlcat(dst, src, len); - if (IS_ENABLED(CONFIG_CMDLINE_EXTEND)) + if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) || IS_ENABLED(CONFIG_CMDLINE_APPEND)) cmdline_strlcat(dst, " " CONFIG_CMDLINE, len); } diff --git a/init/Kconfig b/init/Kconfig index 5f5c776ef192..af0d84662cc2 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -117,6 +117,58 @@ config INIT_ENV_ARG_LIMIT Maximum of each of the number of arguments and environment variables passed to init from the kernel command line. +config GENERIC_CMDLINE + bool + +config CMDLINE + string "Default kernel command string" if GENERIC_CMDLINE + default "" + help + Defines a default kernel command string. + If this string is not empty, additional choices are proposed + below to determine how it will be used by the kernel. + +choice + prompt "Kernel command line type" if CMDLINE != "" + default CMDLINE_PREPEND if ARCH_WANT_CMDLINE_PREPEND_BY_DEFAULT + default CMDLINE_FROM_BOOTLOADER + depends on GENERIC_CMDLINE + help + Determine how the default kernel arguments are combined with any + arguments passed by the bootloader if any. + +config CMDLINE_FROM_BOOTLOADER + bool "Use bootloader kernel arguments if available" + help + Uses the command-line options passed by the boot loader. If + the boot loader doesn't provide any, the default kernel command + string provided in CMDLINE will be used. + +config CMDLINE_APPEND + bool "Append to the bootloader kernel arguments" + help + The default kernel command string will be appended to the + command-line arguments provided by the bootloader. + +config CMDLINE_PREPEND + bool "Prepend to the bootloader kernel arguments" + help + The default kernel command string will be prepended to the + command-line arguments provided by the bootloader. + +config CMDLINE_FORCE + bool "Always use the default kernel command string" + help + Always use the default kernel command string, ignoring any + arguments provided by the bootloader. +endchoice + +config CMDLINE_EXTEND + bool + default CMDLINE_APPEND + help + To be removed once all architectures are converted to generic CMDLINE + config COMPILE_TEST bool "Compile also drivers which will not load" depends on HAS_IOMEM -- 2.25.0
