X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=arch%2Fpowerpc%2Fboot%2Fcrt0.S;h=5a4215c4b0146aa063fe87c5bb503a398232f6d3;hb=18062a91d2ddc40e19fc674afeb7cad58cfa23ab;hp=d2f2ace56cd34df5e1203a85ce5248e763e3133a;hpb=1e6b39fbb61800e3ecee58dc8c4bca57c89365cd;p=linux-2.6

diff --git a/arch/powerpc/boot/crt0.S b/arch/powerpc/boot/crt0.S
index d2f2ace56c..5a4215c4b0 100644
--- 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