--- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1568,6 +1568,14 @@ config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEN endchoice +config CMDLINE_OVERRIDE + bool "Use alternative cmdline from device tree" + help + Some bootloaders may have uneditable bootargs. While CMDLINE_FORCE can + be used, this is not a good option for kernels that are shared across + devices. This setting enables using "chosen/cmdline-override" as the + cmdline if it exists in the device tree. + config CMDLINE string "Default kernel command string" default "" --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -1189,6 +1189,17 @@ int __init early_init_dt_scan_chosen(cha if (p != NULL && l > 0) strlcat(cmdline, p, min_t(int, strlen(cmdline) + (int)l, COMMAND_LINE_SIZE)); + /* CONFIG_CMDLINE_OVERRIDE is used to fallback to a different + * device tree option of chosen/bootargs-override. This is + * helpful on boards where u-boot sets bootargs, and is unable + * to be modified. + */ +#ifdef CONFIG_CMDLINE_OVERRIDE + p = of_get_flat_dt_prop(node, "bootargs-override", &l); + if (p != NULL && l > 0) + strlcpy(cmdline, p, min((int)l, COMMAND_LINE_SIZE)); +#endif + handle_cmdline: /* * CONFIG_CMDLINE is meant to be a default in case nothing else --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2307,6 +2307,14 @@ config CMDLINE_FORCE endchoice +config CMDLINE_OVERRIDE + bool "Use alternative cmdline from device tree" + help + Some bootloaders may have uneditable bootargs. While CMDLINE_FORCE can + be used, this is not a good option for kernels that are shared across + devices. This setting enables using "chosen/cmdline-override" as the + cmdline if it exists in the device tree. + config EFI_STUB bool