From 71270226b14733a4b1f2cde58ea9265caa50b38d Mon Sep 17 00:00:00 2001 From: Adrian Panella Date: Thu, 9 Mar 2017 09:37:17 +0100 Subject: [PATCH 67/69] generic: Mangle bootloader's kernel arguments The command-line arguments provided by the boot loader will be appended to a new device tree property: bootloader-args. If there is a property "append-rootblock" in DT under /chosen and a root= option in bootloaders command line it will be parsed and added to DT bootargs with the form: XX. Only command line ATAG will be processed, the rest of the ATAGs sent by bootloader will be ignored. This is usefull in dual boot systems, to get the current root partition without afecting the rest of the system. Signed-off-by: Adrian Panella --- arch/arm/Kconfig | 11 +++++ arch/arm/boot/compressed/atags_to_fdt.c | 72 ++++++++++++++++++++++++++++++++- init/main.c | 16 ++++++++ 3 files changed, 98 insertions(+), 1 deletion(-) --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1588,6 +1588,17 @@ config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEN The command-line arguments provided by the boot loader will be appended to the the device tree bootargs property. +config ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE + bool "Append rootblock parsing bootloader's kernel arguments" + help + The command-line arguments provided by the boot loader will be + appended to a new device tree property: bootloader-args. + If there is a property "append-rootblock" in DT under /chosen + and a root= option in bootloaders command line it will be parsed + and added to DT bootargs with the form: XX. + Only command line ATAG will be processed, the rest of the ATAGs + sent by bootloader will be ignored. + endchoice config CMDLINE --- a/arch/arm/boot/compressed/atags_to_fdt.c +++ b/arch/arm/boot/compressed/atags_to_fdt.c @@ -5,6 +5,8 @@ #if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND) #define do_extend_cmdline 1 +#elif defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE) +#define do_extend_cmdline 1 #else #define do_extend_cmdline 0 #endif @@ -20,6 +22,7 @@ static int node_offset(void *fdt, const return offset; } +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE static int setprop(void *fdt, const char *node_path, const char *property, void *val_array, int size) { @@ -28,6 +31,7 @@ static int setprop(void *fdt, const char return offset; return fdt_setprop(fdt, offset, property, val_array, size); } +#endif static int setprop_string(void *fdt, const char *node_path, const char *property, const char *string) @@ -38,6 +42,7 @@ static int setprop_string(void *fdt, con return fdt_setprop_string(fdt, offset, property, string); } +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE static int setprop_cell(void *fdt, const char *node_path, const char *property, uint32_t val) { @@ -46,6 +51,7 @@ static int setprop_cell(void *fdt, const return offset; return fdt_setprop_cell(fdt, offset, property, val); } +#endif static const void *getprop(const void *fdt, const char *node_path, const char *property, int *len) @@ -58,6 +64,7 @@ static const void *getprop(const void *f return fdt_getprop(fdt, offset, property, len); } +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE static uint32_t get_cell_size(const void *fdt) { int len; @@ -68,6 +75,81 @@ static uint32_t get_cell_size(const void cell_size = fdt32_to_cpu(*size_len); return cell_size; } +#endif + +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE) +/** + * taken from arch/x86/boot/string.c + * local_strstr - Find the first substring in a %NUL terminated string + * @s1: The string to be searched + * @s2: The string to search for + */ +static char *local_strstr(const char *s1, const char *s2) +{ + size_t l1, l2; + + l2 = strlen(s2); + if (!l2) + return (char *)s1; + l1 = strlen(s1); + while (l1 >= l2) { + l1--; + if (!memcmp(s1, s2, l2)) + return (char *)s1; + s1++; + } + return NULL; +} + +static char *append_rootblock(char *dest, const char *str, int len, void *fdt) +{ + char *ptr, *end, *tmp; + const char *root="root="; + const char *find_rootblock; + int i, l; + const char *rootblock; + + find_rootblock = getprop(fdt, "/chosen", "find-rootblock", &l); + if (!find_rootblock) + find_rootblock = root; + + //ARM doesn't have __HAVE_ARCH_STRSTR, so it was copied from x86 + ptr = local_strstr(str, find_rootblock); + + if(!ptr) + return dest; + + end = strchr(ptr, ' '); + end = end ? (end - 1) : (strchr(ptr, 0) - 1); + + // Some boards ubi.mtd=XX,ZZZZ, so let's check for '," too. + tmp = strchr(ptr, ','); + + if(tmp) + end = end < tmp ? end : tmp - 1; + + //find partition number (assumes format root=/dev/mtdXX | /dev/mtdblockXX | yy:XX | ubi.mtd=XX,ZZZZ ) + for( i = 0; end >= ptr && *end >= '0' && *end <= '9'; end--, i++); + ptr = end + 1; + + /* if append-rootblock property is set use it to append to command line */ + rootblock = getprop(fdt, "/chosen", "append-rootblock", &l); + if(rootblock != NULL) { + if(*dest != ' ') { + *dest = ' '; + dest++; + len++; + } + if (len + l + i <= COMMAND_LINE_SIZE) { + memcpy(dest, rootblock, l); + dest += l - 1; + memcpy(dest, ptr, i); + dest += i; + } + } + return dest; +} +#endif static void merge_fdt_bootargs(void *fdt, const char *fdt_cmdline) { @@ -88,18 +170,28 @@ static void merge_fdt_bootargs(void *fdt /* and append the ATAG_CMDLINE */ if (fdt_cmdline) { + +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE) + //save original bootloader args + //and append ubi.mtd with root partition number to current cmdline + setprop_string(fdt, "/chosen", "bootloader-args", fdt_cmdline); + ptr = append_rootblock(ptr, fdt_cmdline, len, fdt); + +#else len = strlen(fdt_cmdline); if (ptr - cmdline + len + 2 < COMMAND_LINE_SIZE) { *ptr++ = ' '; memcpy(ptr, fdt_cmdline, len); ptr += len; } +#endif } *ptr = '\0'; setprop_string(fdt, "/chosen", "bootargs", cmdline); } +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE static void hex_str(char *out, uint32_t value) { uint32_t digit; @@ -117,6 +209,7 @@ static void hex_str(char *out, uint32_t } *out = '\0'; } +#endif /* * Convert and fold provided ATAGs into the provided FDT. @@ -131,9 +224,11 @@ int atags_to_fdt(void *atag_list, void * struct tag *atag = atag_list; /* In the case of 64 bits memory size, need to reserve 2 cells for * address and size for each bank */ +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE __be32 mem_reg_property[2 * 2 * NR_BANKS]; - int memcount = 0; - int ret, memsize; + int memsize, memcount = 0; +#endif + int ret; /* make sure we've got an aligned pointer */ if ((u32)atag_list & 0x3) @@ -168,7 +263,9 @@ int atags_to_fdt(void *atag_list, void * else setprop_string(fdt, "/chosen", "bootargs", atag->u.cmdline.cmdline); - } else if (atag->hdr.tag == ATAG_MEM) { + } +#ifndef CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE + else if (atag->hdr.tag == ATAG_MEM) { if (memcount >= sizeof(mem_reg_property)/4) continue; if (!atag->u.mem.size) @@ -212,6 +309,10 @@ int atags_to_fdt(void *atag_list, void * setprop(fdt, "/memory", "reg", mem_reg_property, 4 * memcount * memsize); } +#else + + } +#endif return fdt_pack(fdt); } --- a/init/main.c +++ b/init/main.c @@ -112,6 +112,10 @@ #include +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE) +#include +#endif + static int kernel_init(void *); extern void init_IRQ(void); @@ -991,6 +995,18 @@ asmlinkage __visible void __init __no_sa pr_notice("Kernel command line: %s\n", saved_command_line); /* parameters may set static keys */ jump_label_init(); + +#if defined(CONFIG_ARM_ATAG_DTB_COMPAT_CMDLINE_MANGLE) + //Show bootloader's original command line for reference + if(of_chosen) { + const char *prop = of_get_property(of_chosen, "bootloader-args", NULL); + if(prop) + pr_notice("Bootloader command line (ignored): %s\n", prop); + else + pr_notice("Bootloader command line not present\n"); + } +#endif + parse_early_param(); after_dashes = parse_args("Booting kernel", static_command_line, __start___param,