/* * start.S: blob start code * * Copyright (C) 1999 2000 2001 Erik Mouw (J.A.K.Mouw@its.tudelft.nl) and *                     Jan-Derk Bakker (J.D.Bakker@its.tudelft.nl) * * 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. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA * *//* * This is the blob start code. The SA-1100 jumps to address 0x00000000 * after a reset. We put a single branch code at this position which jumps * to a safe region to do the actual setup. All other vectors just point * to an endless loop for the moment. * * Documentation: * [1] Intel Corporation, "Intel StrongARM SA-1100 Microprocessor *     Developer's Manual", April 1999 * [2] S. Furber, "ARM System Architecture", Addison Wesley Longman *     Ltd., Essex, England, 1996. * [3] Intel Corporation, "Intel StrongARM SA-1110 Microprocessor *     Advanced Developer's manual, December 1999 */.ident "$Id: start.S,v 1.2 2001/08/06 22:44:52 erikm Exp $"#ifdef HAVE_CONFIG_H# include <config.h>#endif.text/* Jump vector table as in table 3.1 in [1] */.globl _start_start:	b	reset	b	undefined_instruction	b	software_interrupt	b	prefetch_abort	b	data_abort	b	not_used	b	irq	b	fiq/* some defines to make life easier *//* Register addresses can be found in [1] Appendix A */IC_BASE:        .word   0x90050000#define ICMR    0x04	PWR_BASE:	.word	0x90020000#define PSPR	0x08#define PPCR	0x14	RST_BASE:	.word	0x90030000#define RCSR	0x04/* main memory starts at 0xc0000000 */MEM_START:	.long	0xc0000000/* The initial CPU speed. Note that the SA11x0 CPUs can be safely overclocked: * 190 MHz CPUs are able to run at 221 MHz, 133 MHz CPUs can do 206 Mhz. */#if (defined ASSABET) || (defined CLART) || (defined LART) \	|| (defined NESA) || (defined NESA)cpuspeed:	.long	0x0b	/* 221 MHz */#elif defined SHANNONcpuspeed:	.long	0x09	/* 191.7 MHz */#else#warning "FIXME: Include code to use the correct clock speed for your board"cpuspeed:	.long	0x05	/* safe 133 MHz speed */#endif/* the actual reset code */reset:	/* First, mask **ALL** interrupts */	ldr	r0, IC_BASE	mov	r1, #0x00	str	r1, [r0, #ICMR]	/* switch CPU to correct speed */	ldr	r0, PWR_BASE	LDR	r1, cpuspeed	str	r1, [r0, #PPCR]	/* setup memory */	bl	memsetup	/* init LED */	bl	ledinit		/* check if this is a wake-up from sleep */	ldr	r0, RST_BASE	ldr	r1, [r0, #RCSR]	and	r1, r1, #0x0f	teq	r1, #0x08	bne	normal_boot	/* no, continue booting */	/* yes, a wake-up. clear RCSR by writing a 1 (see 9.6.2.1 from [1]) */	mov	r1, #0x08	str	r1, [r0, #RCSR]	;		/* get the value from the PSPR and jump to it */	ldr	r0, PWR_BASE	ldr	r1, [r0, #PSPR]	mov	pc, r1normal_boot:	/* enable I-cache */	mrc	p15, 0, r1, c1, c0, 0	@ read control reg	orr	r1, r1, #0x1000		@ set Icache	mcr	p15, 0, r1, c1, c0, 0	@ write it back	/* check the first 1MB  in increments of 4k */	mov	r7, #0x1000	mov	r6, r7, lsl #8	/* 4k << 2^8 = 1MB */	ldr	r5, MEM_STARTmem_test_loop:	mov	r0, r5	bl	testram	teq	r0, #1	beq	badram	add	r5, r5, r7	subs	r6, r6, r7	bne	mem_test_loop	/* the first megabyte is OK, so let's clear it */	mov	r0, #((1024 * 1024) / (8 * 4))	/* 1MB in steps of 32 bytes */	ldr	r1, MEM_START	mov	r2, #0	mov	r3, #0	mov	r4, #0	mov	r5, #0	mov	r6, #0	mov	r7, #0	mov	r8, #0	mov	r9, #0clear_loop:	stmia	r1!, {r2-r9}	subs	r0, r0, #(8 * 4)	bne	clear_loop	/* get a clue where we are running, so we know what to copy */	and	r0, pc, #0xff000000	/* we don't care about the low bits */		/* relocate the second stage loader */	add	r2, r0, #(128 * 1024)	/* blob is 128kB */	add	r0, r0, #0x400		/* skip first 1024 bytes */	ldr	r1, MEM_START	add	r1, r1, #0x400		/* skip over here as well */	/* r0 = source address	 * r1 = target address	 * r2 = source end address	 */copy_loop:	ldmia	r0!, {r3-r10}	stmia	r1!, {r3-r10}	cmp	r0, r2	ble	copy_loop	/* turn off the LED. if it stays off it is an indication that	 * we didn't make it into the C code 	 */	bl led_off	/* set up the stack pointer */	ldr	r0, MEM_START	add	r1,r0, #(1024 * 1024) 	sub	sp, r1, #0x04	/* blob is copied to ram, so jump to it */	add	r0, r0, #0x400	mov	pc, r0badram:	b	blinky			blinky:	/* This is test code to blink the LED           very useful if nothing else works */	bl	led_on	bl	wait_loop	bl	led_off	bl	wait_loop	b blinkywait_loop:	/* busy wait loop*/	mov	r2, #0x1000000wait_loop1:	subs	r2, r2, #1	bne	wait_loop1	mov	pc, lr			undefined_instruction:	b	blinkysoftware_interrupt:	/* NOTE: This is NOT an error! If you think that blob should return	 * from software interrupts, you're plain WRONG. The source of the	 * problem is in the kernel: you should *disable* CONFIG_ANGELBOOT	 * simply because blob is not angel. -- Erik	 */	b	blinkyprefetch_abort:	b	blinkydata_abort:	b	blinkynot_used:	b	blinkyirq:	b	blinkyfiq:	b	blinky