diff options
| -rw-r--r-- | arch/arm/Kconfig | 19 | ||||
| -rw-r--r-- | arch/arm/boot/compressed/atags_to_fdt.c | 62 |
2 files changed, 79 insertions, 2 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index b649c5904a4f..8c9d264f2108 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1960,6 +1960,25 @@ config ARM_ATAG_DTB_COMPAT bootloaders, this option allows zImage to extract the information from the ATAG list and store it at run time into the appended DTB. +choice + prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT + default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER + +config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER + bool "Use bootloader kernel arguments if available" + help + Uses the command-line options passed by the boot loader instead of + the device tree bootargs property. If the boot loader doesn't provide + any, the device tree bootargs property will be used. + +config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND + bool "Extend with bootloader kernel arguments" + help + The command-line arguments provided by the boot loader will be + appended to the the device tree bootargs property. + +endchoice + config CMDLINE string "Default kernel command string" default "" diff --git a/arch/arm/boot/compressed/atags_to_fdt.c b/arch/arm/boot/compressed/atags_to_fdt.c index 797f04bedb47..aabc02a68482 100644 --- a/arch/arm/boot/compressed/atags_to_fdt.c +++ b/arch/arm/boot/compressed/atags_to_fdt.c @@ -1,6 +1,12 @@ #include <asm/setup.h> #include <libfdt.h> +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND) +#define do_extend_cmdline 1 +#else +#define do_extend_cmdline 0 +#endif + static int node_offset(void *fdt, const char *node_path) { int offset = fdt_path_offset(fdt, node_path); @@ -36,6 +42,48 @@ static int setprop_cell(void *fdt, const char *node_path, return fdt_setprop_cell(fdt, offset, property, val); } +static const void *getprop(const void *fdt, const char *node_path, + const char *property, int *len) +{ + int offset = fdt_path_offset(fdt, node_path); + + if (offset == -FDT_ERR_NOTFOUND) + return NULL; + + return fdt_getprop(fdt, offset, property, len); +} + +static void merge_fdt_bootargs(void *fdt, const char *fdt_cmdline) +{ + char cmdline[COMMAND_LINE_SIZE]; + const char *fdt_bootargs; + char *ptr = cmdline; + int len = 0; + + /* copy the fdt command line into the buffer */ + fdt_bootargs = getprop(fdt, "/chosen", "bootargs", &len); + if (fdt_bootargs) + if (len < COMMAND_LINE_SIZE) { + memcpy(ptr, fdt_bootargs, len); + /* len is the length of the string + * including the NULL terminator */ + ptr += len - 1; + } + + /* and append the ATAG_CMDLINE */ + if (fdt_cmdline) { + len = strlen(fdt_cmdline); + if (ptr - cmdline + len + 2 < COMMAND_LINE_SIZE) { + *ptr++ = ' '; + memcpy(ptr, fdt_cmdline, len); + ptr += len; + } + } + *ptr = '\0'; + + setprop_string(fdt, "/chosen", "bootargs", cmdline); +} + /* * Convert and fold provided ATAGs into the provided FDT. * @@ -72,8 +120,18 @@ int atags_to_fdt(void *atag_list, void *fdt, int total_space) for_each_tag(atag, atag_list) { if (atag->hdr.tag == ATAG_CMDLINE) { - setprop_string(fdt, "/chosen", "bootargs", - atag->u.cmdline.cmdline); + /* Append the ATAGS command line to the device tree + * command line. + * NB: This means that if the same parameter is set in + * the device tree and in the tags, the one from the + * tags will be chosen. + */ + if (do_extend_cmdline) + merge_fdt_bootargs(fdt, + atag->u.cmdline.cmdline); + else + setprop_string(fdt, "/chosen", "bootargs", + atag->u.cmdline.cmdline); } else if (atag->hdr.tag == ATAG_MEM) { if (memcount >= sizeof(mem_reg_property)/4) continue; |