patch-2.4.19 linux-2.4.19/arch/ppc64/boot/crt0.S

• Lines: 49
• Date: Fri Aug 2 17:39:43 2002
• Orig file: linux-2.4.18/arch/ppc64/boot/crt0.S
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.18/arch/ppc64/boot/crt0.S linux-2.4.19/arch/ppc64/boot/crt0.S
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) Paul Mackerras 1997.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * NOTE: this code runs in 32 bit mode and is packaged as ELF32.
+ */
+
+#include <asm/ppc_asm.tmpl>
+
+	.text
+	.globl	_start
+_start:
+	lis	r9,_start@h
+	lis	r8,_etext@ha
+	addi	r8,r8,_etext@l
+1:	dcbf	r0,r9
+	icbi	r0,r9
+	addi	r9,r9,0x20
+	cmplwi	0,r9,8
+	blt	1b
+	sync
+	isync
+
+	## Clear out the BSS as per ANSI C requirements
+
+	lis	r7,_end@ha
+	addi    r7,r7,_end@l		# r7 = &_end 
+	lis	r8,__bss_start@ha	# 
+	addi    r8,r8,__bss_start@l	# r8 = &_bss_start
+
+	## Determine how large an area, in number of words, to clear
+
+	subf	r7,r8,r7		# r7 = &_end - &_bss_start + 1 
+	addi	r7,r7,3			# r7 += 3 
+	srwi.	r7,r7,2			# r7 = size in words.
+	beq	3f			# If the size is zero, don't bother
+	addi	r8,r8,-4		# r8 -= 4 
+	mtctr	r7			# SPRN_CTR = number of words to clear
+	li	r0,0			# r0 = 0
+2:	stwu	r0,4(r8)		# Clear out a word
+	bdnz	2b			# Keep clearing until done
+3:
+	b	start
+