diff options
| author | Grant Likely <grant.likely@secretlab.ca> | 2011-04-28 14:27:20 -0600 |
|---|---|---|
| committer | Grant Likely <grant.likely@secretlab.ca> | 2011-05-11 15:12:32 +0200 |
| commit | 4c2896e88d976d0e5b2213c64cde885f5677fa2b (patch) | |
| tree | d5573124e35cb3b81b7ac56fb4d7708eacf4991d /arch/arm/kernel | |
| parent | 7ee4b98eca42c1ff1df7dcf443dac07f0a2ea93d (diff) | |
arm/dt: Make __vet_atags also accept a dtb image
The dtb is passed to the kernel via register r2, which is the same
method that is used to pass an atags pointer. This patch modifies
__vet_atags to not clear r2 when it encounters a dtb image.
v2: fixed bugs pointed out by Nicolas Pitre
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'arch/arm/kernel')
| -rw-r--r-- | arch/arm/kernel/head-common.S | 24 | ||||
| -rw-r--r-- | arch/arm/kernel/head.S | 8 |
2 files changed, 22 insertions, 10 deletions
diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S index c84b57d27d07..854bd22380d3 100644 --- a/arch/arm/kernel/head-common.S +++ b/arch/arm/kernel/head-common.S @@ -15,6 +15,12 @@ #define ATAG_CORE_SIZE ((2*4 + 3*4) >> 2) #define ATAG_CORE_SIZE_EMPTY ((2*4) >> 2) +#ifdef CONFIG_CPU_BIG_ENDIAN +#define OF_DT_MAGIC 0xd00dfeed +#else +#define OF_DT_MAGIC 0xedfe0dd0 /* 0xd00dfeed in big-endian */ +#endif + /* * Exception handling. Something went wrong and we can't proceed. We * ought to tell the user, but since we don't have any guarantee that @@ -28,20 +34,26 @@ /* Determine validity of the r2 atags pointer. The heuristic requires * that the pointer be aligned, in the first 16k of physical RAM and - * that the ATAG_CORE marker is first and present. Future revisions + * that the ATAG_CORE marker is first and present. If CONFIG_OF_FLATTREE + * is selected, then it will also accept a dtb pointer. Future revisions * of this function may be more lenient with the physical address and * may also be able to move the ATAGS block if necessary. * * Returns: - * r2 either valid atags pointer, or zero + * r2 either valid atags pointer, valid dtb pointer, or zero * r5, r6 corrupted */ __vet_atags: tst r2, #0x3 @ aligned? bne 1f - ldr r5, [r2, #0] @ is first tag ATAG_CORE? - cmp r5, #ATAG_CORE_SIZE + ldr r5, [r2, #0] +#ifdef CONFIG_OF_FLATTREE + ldr r6, =OF_DT_MAGIC @ is it a DTB? + cmp r5, r6 + beq 2f +#endif + cmp r5, #ATAG_CORE_SIZE @ is first tag ATAG_CORE? cmpne r5, #ATAG_CORE_SIZE_EMPTY bne 1f ldr r5, [r2, #4] @@ -49,7 +61,7 @@ __vet_atags: cmp r5, r6 bne 1f - mov pc, lr @ atag pointer is ok +2: mov pc, lr @ atag/dtb pointer is ok 1: mov r2, #0 mov pc, lr @@ -61,7 +73,7 @@ ENDPROC(__vet_atags) * * r0 = cp#15 control register * r1 = machine ID - * r2 = atags pointer + * r2 = atags/dtb pointer * r9 = processor ID */ __INIT diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index c9173cfbbc74..a5e5c5b9b48e 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -59,7 +59,7 @@ * * This is normally called from the decompressor code. The requirements * are: MMU = off, D-cache = off, I-cache = dont care, r0 = 0, - * r1 = machine nr, r2 = atags pointer. + * r1 = machine nr, r2 = atags or dtb pointer. * * This code is mostly position independent, so if you link the kernel at * 0xc0008000, you call this at __pa(0xc0008000). @@ -91,7 +91,7 @@ ENTRY(stext) #endif /* - * r1 = machine no, r2 = atags, + * r1 = machine no, r2 = atags or dtb, * r8 = phys_offset, r9 = cpuid, r10 = procinfo */ bl __vet_atags @@ -339,7 +339,7 @@ __secondary_data: * * r0 = cp#15 control register * r1 = machine ID - * r2 = atags pointer + * r2 = atags or dtb pointer * r4 = page table pointer * r9 = processor ID * r13 = *virtual* address to jump to upon completion @@ -376,7 +376,7 @@ ENDPROC(__enable_mmu) * * r0 = cp#15 control register * r1 = machine ID - * r2 = atags pointer + * r2 = atags or dtb pointer * r9 = processor ID * r13 = *virtual* address to jump to upon completion * |