diff options
| -rw-r--r-- | arch/arc/kernel/head.S | 4 | ||||
| -rw-r--r-- | arch/arc/kernel/setup.c | 87 |
2 files changed, 64 insertions, 27 deletions
diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S index 26e33a8b2d18..1f945d0f40da 100644 --- a/arch/arc/kernel/head.S +++ b/arch/arc/kernel/head.S @@ -103,9 +103,9 @@ ENTRY(stext) #ifdef CONFIG_ARC_UBOOT_SUPPORT ; Uboot - kernel ABI ; r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2 - ; r1 = magic number (board identity, unused as of now + ; r1 = magic number (always zero as of now) ; r2 = pointer to uboot provided cmdline or external DTB in mem - ; These are handled later in setup_arch() + ; These are handled later in handle_uboot_args() st r0, [@uboot_tag] st r2, [@uboot_arg] #endif diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c index def19b0ef8c6..8bb156164556 100644 --- a/arch/arc/kernel/setup.c +++ b/arch/arc/kernel/setup.c @@ -462,43 +462,80 @@ void setup_processor(void) arc_chk_core_config(); } -static inline int is_kernel(unsigned long addr) +static inline bool uboot_arg_invalid(unsigned long addr) { - if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end) - return 1; - return 0; + /* + * Check that it is a untranslated address (although MMU is not enabled + * yet, it being a high address ensures this is not by fluke) + */ + if (addr < PAGE_OFFSET) + return true; + + /* Check that address doesn't clobber resident kernel image */ + return addr >= (unsigned long)_stext && addr <= (unsigned long)_end; } -void __init setup_arch(char **cmdline_p) +#define IGNORE_ARGS "Ignore U-boot args: " + +/* uboot_tag values for U-boot - kernel ABI revision 0; see head.S */ +#define UBOOT_TAG_NONE 0 +#define UBOOT_TAG_CMDLINE 1 +#define UBOOT_TAG_DTB 2 + +void __init handle_uboot_args(void) { + bool use_embedded_dtb = true; + bool append_cmdline = false; + #ifdef CONFIG_ARC_UBOOT_SUPPORT - /* make sure that uboot passed pointer to cmdline/dtb is valid */ - if (uboot_tag && is_kernel((unsigned long)uboot_arg)) - panic("Invalid uboot arg\n"); + /* check that we know this tag */ + if (uboot_tag != UBOOT_TAG_NONE && + uboot_tag != UBOOT_TAG_CMDLINE && + uboot_tag != UBOOT_TAG_DTB) { + pr_warn(IGNORE_ARGS "invalid uboot tag: '%08x'\n", uboot_tag); + goto ignore_uboot_args; + } + + if (uboot_tag != UBOOT_TAG_NONE && + uboot_arg_invalid((unsigned long)uboot_arg)) { + pr_warn(IGNORE_ARGS "invalid uboot arg: '%px'\n", uboot_arg); + goto ignore_uboot_args; + } + + /* see if U-boot passed an external Device Tree blob */ + if (uboot_tag == UBOOT_TAG_DTB) { + machine_desc = setup_machine_fdt((void *)uboot_arg); - /* See if u-boot passed an external Device Tree blob */ - machine_desc = setup_machine_fdt(uboot_arg); /* uboot_tag == 2 */ - if (!machine_desc) + /* external Device Tree blob is invalid - use embedded one */ + use_embedded_dtb = !machine_desc; + } + + if (uboot_tag == UBOOT_TAG_CMDLINE) + append_cmdline = true; + +ignore_uboot_args: #endif - { - /* No, so try the embedded one */ + + if (use_embedded_dtb) { machine_desc = setup_machine_fdt(__dtb_start); if (!machine_desc) panic("Embedded DT invalid\n"); + } - /* - * If we are here, it is established that @uboot_arg didn't - * point to DT blob. Instead if u-boot says it is cmdline, - * append to embedded DT cmdline. - * setup_machine_fdt() would have populated @boot_command_line - */ - if (uboot_tag == 1) { - /* Ensure a whitespace between the 2 cmdlines */ - strlcat(boot_command_line, " ", COMMAND_LINE_SIZE); - strlcat(boot_command_line, uboot_arg, - COMMAND_LINE_SIZE); - } + /* + * NOTE: @boot_command_line is populated by setup_machine_fdt() so this + * append processing can only happen after. + */ + if (append_cmdline) { + /* Ensure a whitespace between the 2 cmdlines */ + strlcat(boot_command_line, " ", COMMAND_LINE_SIZE); + strlcat(boot_command_line, uboot_arg, COMMAND_LINE_SIZE); } +} + +void __init setup_arch(char **cmdline_p) +{ + handle_uboot_args(); /* Save unparsed command line copy for /proc/cmdline */ *cmdline_p = boot_command_line; |