diff options
Diffstat (limited to 'arch/microblaze/kernel/head.S')
| -rw-r--r-- | arch/microblaze/kernel/head.S | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/arch/microblaze/kernel/head.S b/arch/microblaze/kernel/head.S index e568d6ec621b..e41c6ce2a7be 100644 --- a/arch/microblaze/kernel/head.S +++ b/arch/microblaze/kernel/head.S @@ -31,6 +31,7 @@ #include <linux/linkage.h> #include <asm/thread_info.h> #include <asm/page.h> +#include <asm/prom.h> /* for OF_DT_HEADER */ #ifdef CONFIG_MMU #include <asm/setup.h> /* COMMAND_LINE_SIZE */ @@ -54,11 +55,19 @@ ENTRY(_start) andi r1, r1, ~2 mts rmsr, r1 -/* save fdt to kernel location */ -/* r7 stores pointer to fdt blob */ - beqi r7, no_fdt_arg +/* r7 may point to an FDT, or there may be one linked in. + if it's in r7, we've got to save it away ASAP. + We ensure r7 points to a valid FDT, just in case the bootloader + is broken or non-existent */ + beqi r7, no_fdt_arg /* NULL pointer? don't copy */ + lw r11, r0, r7 /* Does r7 point to a */ + rsubi r11, r11, OF_DT_HEADER /* valid FDT? */ + beqi r11, _prepare_copy_fdt + or r7, r0, r0 /* clear R7 when not valid DTB */ + bnei r11, no_fdt_arg /* No - get out of here */ +_prepare_copy_fdt: or r11, r0, r0 /* incremment */ - ori r4, r0, TOPHYS(_fdt_start) /* save bram context */ + ori r4, r0, TOPHYS(_fdt_start) ori r3, r0, (0x4000 - 4) _copy_fdt: lw r12, r7, r11 /* r12 = r7 + r11 */ |