############################################################################# Filename:      start.S## Version:       $Id: start.S,v 1.15 1999/10/03 22:03:52 erikm Exp $## Copyright:     Copyright (C) 1999, Erik Mouw## Author:        Erik Mouw <J.A.K.Mouw@its.tudelft.nl>## Description:   blob start code## Created at:    Sun Jul 18 20:29:08 1999## Modified by:   Erik Mouw <J.A.K.Mouw@its.tudelft.nl>## Modified at:   Sun Oct  3 21:07:36 1999###########################################################################/* * start.S: blob start code * * Copyright (C) 1999  Erik Mouw (J.A.K.Mouw@its.tudelft.nl) and  *                     Jan-Derk Bakker (J.D.Bakker@its.tudelft.nl) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA * *//* * This is the blob start code. The SA-1100 jumps to address 0x00000000 * after a reset. We put a single branch code at this position which jumps * to a safe region to do the actual setup. All other vectors just point * to an endless loop for the moment. * * Documentation:  * [1] Intel Corporation, "Intel StrongARM SA-1100 Microprocessor *     Developer's Manual", April 1999 * [2] S. Furber, "ARM System Architecture", Addison Wesley Longman *     Ltd., Essex, England, 1996. */.ident "$Id: start.S,v 1.15 1999/10/03 22:03:52 erikm Exp $".text/* extern function to blink the LED */.extern blink_led/* Jump vector table as in table 3.1 in [1] */.globl _start_start:	b	reset	b	undefined_instruction	b	software_interrupt	b	abort_prefetch	b	abort_data	b	not_used	b	irq	b	fiq			reset:old_blink_led:		/* Register addresses can be found in [1] Appendix A */	/* Switch the SA-1100 to 220 MHz */	mov	r1, #0x90000000	add	r1, r1, #0x20000	mov	r2, #0xB	str	r2, [r1, #0x14]	/* Set up the DRAM in banks 0 and 1 */	mov	r1, #0xA0000000	mov	r2,     #0xC7000000	add	r2, r2, #0x001C0000	add	r2, r2, #0x00007000	add	r2, r2, #0x0000003F	str	r2, [r1, #0x04]	mov	r2,     #0xFF000000	add	r2, r2, #0x00C70000	add	r2, r2, #0x00001C00	add	r2, r2, #0x00000071	str	r2, [r1, #0x08]		mov	r2,     #0xFF000000	add	r2, r2, #0x00FF0000	add	r2, r2, #0x0000FF00	add	r2, r2, #0x000000FF	str	r2, [r1, #0x0C]		mov	r2,     #0x03000000	add	r2, r2, #0x00340000	add	r2, r2, #0x0000B200	add	r2, r2, #0x00000023	str	r2, [r1, #0x00]	/* Try to transmit over the serial port III. */	/* Do port setup the paranoid way */	/* First, mask **ALL** interrupts */	mov	r1, #0x90000000	add	r1, r1, #0x50000	mov	r2, #0x00	str	r2, [r1, #0x4]	/* Now clear all 'sticky' bits in serial III registers, cf. [1] 11.11 */	mov	r1, #0x80000000	add	r1, r1, #0x50000	mov	r2, #0xFF	str	r2, [r1, #0x1C]		/* Set the serial port to sensible defaults: no break, no interrupts, */	/* no parity, 8 databits, 1 stopbit. */	mov	r2, #0x00	str	r2, [r1, #0x0C]	mov	r2, #0x08	str	r2, [r1, #0x00]	/* Set BRD to 5, for a baudrate of 38k4 ([1] 11.11.4.1) */	/* Set BRD to 23, for a baudrate of 9k6 ([1] 11.11.4.1) */	mov	r2, #0x00	str	r2, [r1, #0x04]	mov	r2, #23	str	r2, [r1, #0x08]	/* Initialize the GPDR (GPIO Pin Direction Register) in such a	way that the LED is on an output port */	/* load the GPIO base in r2 */		mov	r2, #0x90000000	add	r2, r2, #0x40000	/* Bit 23 is the LED, according to JDB */	mov	r1, #0x00800000	str	r1, [r2, #0x04]	/* The LED controls FORCE_ON, so turn it on here */	str     r1, [r2, #0x08]	/* Prepare to send some characters out in a loop */	mov	r1, #0x80000000	add	r1, r1, #0x50000			/* Enable the transmitter */	mov	r2, #0x02	str	r2, [r1, #0x0C]	/* Send out a welcome message */	adr	r0, welcome	bl	print_str	/* Determine whether this code runs from main flash or external flash */	/* Clue: Main flash is 32 bit, external is 16 bit. */	mov	r1, #0xA0000000	ldr	r0, [r1, #0x10]	ands	r0, r0, #0x04	bne	cpy_ext2int	/* Put the main flash to the correct speed */	mov	r2,     #0xAD000000	add	r2, r2, #0x006C0000	add	r2, r2, #0x00004800	add	r2, r2, #0x00000068	str	r2, [r1, #0x10]	adr	r0, int_flash_str	bl	print_strtest_mem:	/* Start the memory tester, hardcoded bank 0 & 1 for now */	adr	r0, start_test	bl	print_str	/* Erase memory */	adr	r0, zeroing_mem	bl	print_str	mov	r4, #0xC0000000	mov	r5, #0xD0000000	mov	r6, #0x400000	sub	r6, r6, #0x01	mov	r0, r4	bl	print_hexzero_loop:	mov	r0, #0x0	mov	r1, #0x0	mov	r2, #0x0	mov	r3, #0x0	mov	r7, #0x0	mov	r8, #0x0	mov	r9, #0x0	mov	r10, #0x0zero_loop1:	stmia	r4!, {r0-r3, r7-r10}	stmia	r4!, {r0-r3, r7-r10}	stmia	r4!, {r0-r3, r7-r10}	stmia	r4!, {r0-r3, r7-r10}	tst	r4, r6	bne	zero_loop1	adr	r0, del10	bl	print_str	mov	r0, r4	bl	print_hex	cmp	r4, r5	blt	zero_loop	adr	r0, zeroing_done	bl	print_str	mov	r4, #0xC0000000	mov	r5, #0xD0000000	mov	r6, r4 /* Base for current block */	mov	r7, #0x0 /* Diff between r4 and [r4] */	/* Go hunting for aliases */alias_loop:	ldr	r8, [r4]	cmp	r8, #0x0	streq	r4, [r4] /* If the value was zero, load r4 to it */	moveq	r8, r4	sub	r9, r4, r8	cmp	r9, r7 /* Is this a new block ? */	bne	alias_detected	add	r4, r4, #0x1000	cmp	r4, r5	blt	alias_loop		b	alias_donealias_detected:#	adr	r0, block_at_str#	bl	print_str#	mov	r0, r6#	bl	print_hex#	adr	r0, length_str#	bl	print_str#	sub	r0, r4, r6#	bl	print_hex	sub	r8, r6, r7	cmp	r7, #0x0	/* Is this a 'new' block ? */	moveq	r10, r6		/* If so, remember the start of this block...*/ 	moveq	r11, r4		/* ...and the start of the next block */	mov	r6, r4	mov	r7, r9	beq	alias_loop#	adr	r0, alias_for_str#	bl	print_str#	mov	r0, r8#	bl	print_hex	b	alias_loopalias_done:	/* Set up the stack pointer */	sub	sp, r11, #0x04	/* Arg 0 of the C code is the start of the block it can use; */	/* arg 1 is the size of that block. */	mov	r0, r10	sub	r1, r11, r10	/* Jump to the C code */jump_to_c:	bl	c_main	/* The c code should never return ! */	b	resetblinky:	/* The old blinker */	mov     r2, #0x90000000	add     r2, r2, #0x40000	mov     r1, #0x00800000old_led_on:	/* turn on the LED by writing the GPSR (GPIO Pin output Set	Register) */	str	r1, [r2, #0x08]	mov	r4, #0x10000loop1:	subs	r4, r4, #1	bne	loop1old_led_off:	/* turn off the LED by writing the GPCR (GPIO Pin output Clear	Register) */	str	r1, [r2, #0x0c]	mov     r4, #0x10000loop2:	subs    r4, r4, #1	bne	loop2	/* and loop forever */	b	old_led_on.align 4welcome:	.string "\n\r\n\rConsider yourself LARTed!\n\r".align 4int_flash_str:	.string "Running from internal Flash.\n\r".align 4start_test:	.string "Starting the memory tester...\n\r".align 4zeroing_mem:	.string "Zeroing memory...".align 4zeroing_done:	.string "\n\rZeroing done. Testing for aliases...\n\r".align 4del10:	.string "\b\b\b\b\b\b\b\b\b\b".align 4block_at_str:	.string "\n\rBlock at ".align 4length_str:	.string " with length ".align 4alias_for_str:	.string " is an alias of ".align 4	/* Subroutine that sends a string over the serial port */	/* The address of the string should be in r0 */print_str:	/* Save the return address */	mov	r13, r14	mov	r2, r0prs1:	ldrsb	r0, [r2]	add	r2, r2, #0x01	ands	r0, r0, #0xFF	beq	prs2	bl	print_byte	b	prs1prs2:	/* Return */	mov	pc, r13	/* Subroutine to send a hex word (in r0) over the serial port */print_hex:	mov	r13, r14	mov	r2, r0	mov	r3, #0x08	mov	r0, #0x30	bl	print_byte	mov	r0, #0x78	bl	print_byteprh1:	and	r0, r2, #0xF0000000	mov	r0, r0, lsr #28	add	r0, r0, #0x30	cmp	r0, #0x3A	addge	r0, r0, #0x07	bl	print_byte	mov	r2, r2, lsl #4	subs	r3, r3, #0x01		bne	prh1	mov	pc, r13	/* Subroutine that sends a byte over the serial port. */	/* The byte is in r0 */print_byte:	/* Wait for room in the tx fifo */	mov     r1, #0x80000000	add     r1, r1, #0x50000	ldr     r1, [r1, #0x1C]	ands    r1, r1, #0x01	beq	print_byte	mov     r1, #0x80000000	add     r1, r1, #0x50000	str	r0, [r1, #0x14]	mov	pc, r14	cpy_ext2int:	/* Put the Flash to the correct speed */	mov	r1, #0xA0000000	mov	r2,     #0x48000000	add	r2, r2, #0x00680000	add	r2, r2, #0x0000AD00	add	r2, r2, #0x0000006C	str	r2, [r1, #0x10]	adr	r0, ext_flash_str	bl	print_str	/* Get the ID of the internal flash */	mov	r0, #0x0090	add	r0, r0, #0x00900000	bl	data_to_flash	mov	r4, #0x08000000	str	r0, [r4]	ldr	r0, [r4]	bl	data_from_flash	mov	r5, r0	ldr	r0, [r4, #0x04]	bl	data_from_flash	mov	r6, r0	mov	r3, #0x0089	add	r3, r3, #0x00890000	cmp	r3, r5	beq	flash_man_ok	adr	r0, int_unknown_str	bl	print_str	mov	r0, r5	bl	print_hex