path: root/arch/arm/boot/compressed/head.S

/*
 *  linux/arch/arm/boot/compressed/head.S
 *
 *  Copyright (C) 1996-2002 Russell King
 *  Copyright (C) 2004 Hyok S. Choi (MPU support)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/linkage.h>

/*
 * Debugging stuff
 *
 * Note that these macros must not contain any code which is not
 * 100% relocatable.  Any attempt to do so will result in a crash.
 * Please select one of the following when turning on debugging.
 */
#ifdef DEBUG

#if defined(CONFIG_DEBUG_ICEDCC)
		.macro	loadsp, rb
		.endm
		.macro	writeb, ch, rb
		mcr	p14, 0, \ch, c0, c1, 0
		.endm
#else

#include <asm/arch/debug-macro.S>

		.macro	writeb,	ch, rb
		senduart \ch, \rb
		.endm

#if defined(CONFIG_ARCH_SA1100)
		.macro	loadsp, rb
		mov	\rb, #0x80000000	@ physical base address
#ifdef CONFIG_DEBUG_LL_SER3
		add	\rb, \rb, #0x00050000	@ Ser3
#else
		add	\rb, \rb, #0x00010000	@ Ser1
#endif
		.endm
#elif defined(CONFIG_ARCH_IOP331)
		.macro loadsp, rb
                mov   	\rb, #0xff000000
                orr     \rb, \rb, #0x00ff0000
                orr     \rb, \rb, #0x0000f700   @ location of the UART
		.endm
#elif defined(CONFIG_ARCH_S3C2410)
		.macro loadsp, rb
		mov	\rb, #0x50000000
		add	\rb, \rb, #0x4000 * CONFIG_S3C2410_LOWLEVEL_UART_PORT
		.endm
#else
		.macro	loadsp,	rb
		addruart \rb
		.endm
#endif
#endif
#endif

		.macro	kputc,val
		mov	r0, \val
		bl	putc
		.endm

		.macro	kphex,val,len
		mov	r0, \val
		mov	r1, #\len
		bl	phex
		.endm

		.macro	debug_reloc_start
#ifdef DEBUG
		kputc	#'\n'
		kphex	r6, 8		/* processor id */
		kputc	#':'
		kphex	r7, 8		/* architecture id */
		kputc	#':'
		mrc	p15, 0, r0, c1, c0
		kphex	r0, 8		/* control reg */
		kputc	#'\n'
		kphex	r5, 8		/* decompressed kernel start */
		kputc	#'-'
		kphex	r9, 8		/* decompressed kernel end  */
		kputc	#'>'
		kphex	r4, 8		/* kernel execution address */
		kputc	#'\n'
#endif
		.endm

		.macro	debug_reloc_end
#ifdef DEBUG
		kphex	r5, 8		/* end of kernel */
		kputc	#'\n'
		mov	r0, r4
		bl	memdump		/* dump 256 bytes at start of kernel */
#endif
		.endm

		.section ".start", #alloc, #execinstr
/*
 * sort out different calling conventions
 */
		.align
start:
		.type	start,#function
		.rept	8
		mov	r0, r0
		.endr

		b	1f
		.word	0x016f2818		@ Magic numbers to help the loader
		.word	start			@ absolute load/run zImage address
		.word	_edata			@ zImage end address
1:		mov	r7, r1			@ save architecture ID
		mov	r8, r2			@ save atags pointer

#ifndef __ARM_ARCH_2__
		/*
		 * Booting from Angel - need to enter SVC mode and disable
		 * FIQs/IRQs (numeric definitions from angel arm.h source).
		 * We only do this if we were in user mode on entry.
		 */
		mrs	r2, cpsr		@ get current mode
		tst	r2, #3			@ not user?
		bne	not_angel
		mov	r0, #0x17		@ angel_SWIreason_EnterSVC
		swi	0x123456		@ angel_SWI_ARM
not_angel:
		mrs	r2, cpsr		@ turn off interrupts to
		orr	r2, r2, #0xc0		@ prevent angel from running
		msr	cpsr_c, r2
#else
		teqp	pc, #0x0c000003		@ turn off interrupts
#endif

		/*
		 * Note that some cache flushing and other stuff may
		 * be needed here - is there an Angel SWI call for this?
		 */

		/*
		 * some architecture specific code can be inserted
		 * by the linker here, but it should preserve r7, r8, and r9.
		 */

		.text
		adr	r0, LC0
		ldmia	r0, {r1, r2, r3, r4, r5, r6, ip, sp}
		subs	r0, r0, r1		@ calculate the delta offset