Merge branch 'drm-patches' of master.kernel.org:/pub/scm/linux/kernel/git/airlied...

[linux-drm-fsl-dcu.git] / arch / powerpc / boot / crt0.S

diff --git a/arch/powerpc/boot/crt0.S b/arch/powerpc/boot/crt0.S
index d2f2ace56cd34df5e1203a85ce5248e763e3133a..5a4215c4b0146aa063fe87c5bb503a398232f6d3 100644 (file)
--- a/arch/powerpc/boot/crt0.S
+++ b/arch/powerpc/boot/crt0.S
@@ -12,17 +12,26 @@
 #include "ppc_asm.h"
 
        .text
+       /* a procedure descriptor used when booting this as a COFF file */
+_zimage_start_opd:
+       .long   _zimage_start, 0, 0, 0
+
+       .weak   _zimage_start
        .globl  _zimage_start
 _zimage_start:
+       .globl  _zimage_start_lib
+_zimage_start_lib:
+       /* Work out the offset between the address we were linked at
+          and the address where we're running. */
        bl      1f
-
-1:
-       mflr    r0
+1:     mflr    r0
        lis     r9,1b@ha
        addi    r9,r9,1b@l
        subf.   r0,r9,r0
-       beq     3f
+       beq     3f              /* if running at same address as linked */
 
+       /* The .got2 section contains a list of addresses, so add
+          the address offset onto each entry. */
        lis     r9,__got2_start@ha
        addi    r9,r9,__got2_start@l
        lis     r8,__got2_end@ha
@@ -32,15 +41,15 @@ _zimage_start:
        srwi.   r8,r8,2
        mtctr   r8
        add     r9,r0,r9
-2:
-       lwz     r8,0(r9)
+2:     lwz     r8,0(r9)
        add     r8,r8,r0
        stw     r8,0(r9)
        addi    r9,r9,4
        bdnz    2b
 
-3:
-       lis     r9,_start@h
+       /* Do a cache flush for our text, in case the loader didn't */
+3:     lis     r9,_start@ha
+       addi    r9,r9,_start@l
        add     r9,r0,r9
        lis     r8,_etext@ha
        addi    r8,r8,_etext@l
@@ -48,11 +57,39 @@ _zimage_start:
 4:     dcbf    r0,r9
        icbi    r0,r9
        addi    r9,r9,0x20
-       cmplwi  0,r9,8
+       cmplw   cr0,r9,r8
        blt     4b
        sync
        isync
 
-       mr      r6,r1
-       b       start
+       /* Clear the BSS */
+       lis     r9,__bss_start@ha
+       addi    r9,r9,__bss_start@l
+       add     r9,r0,r9
+       lis     r8,_end@ha
+       addi    r8,r8,_end@l
+       add     r8,r0,r8
+       li      r10,0
+5:     stw     r10,0(r9)
+       addi    r9,r9,4
+       cmplw   cr0,r9,r8
+       blt     5b
+
+       /* Possibly set up a custom stack */
+.weak  _platform_stack_top
+       lis     r8,_platform_stack_top@ha
+       addi    r8,r8,_platform_stack_top@l
+       cmpwi   r8,0
+       beq     6f
+       add     r8,r0,r8
+       lwz     r1,0(r8)
+       add     r1,r0,r1
+       li      r0,0
+       stwu    r0,-16(r1)      /* establish a stack frame */
+6:
 
+       /* Call platform_init() */
+       bl      platform_init
+
+       /* Call start */
+       b       start