post1.s

AT91RM9200的完整启动代码：包括loader, boot及U-boot三部分均已编译通过！欢迎下载使用！

/*
 * (C) Copyright 2001
 * Bill Hunter, Wave 7 Optics, [e-mail]
 *  and
 * Erik Theisen, Wave 7 Optics, [e-mail]
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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
 */
/*
 * Description:
 *	Routine to exercise memory for the bringing up of our boards.
 */
#include <config.h>
#include <ppc4xx.h>

#define _LINUX_CONFIG_H 1       /* avoid reading Linux autoconf.h file  */

#include <ppc_asm.tmpl>
#include <ppc_defs.h>

#include <asm/cache.h>
#include <asm/mmu.h>

#include <watchdog.h>

#include "errors.h"

#define _ASMLANGUAGE

	.globl	test_sdram
	.globl	test_led
	.globl	log_stat
	.globl	log_warn
	.globl	log_err
	.globl  temp_uart_init
	.globl  post_puts
	.globl  disp_hex

/*****************************************************
*******   Text Strings for low level printing   ******
*******          In section got2               *******
*****************************************************/

/*
 * Define the text strings for errors and warnings.
 * Switch to .data section.
 */
	.section ".data"
err_str: 	.asciz "*** POST ERROR   = "
warn_str:	.asciz "*** POST WARNING = "
end_str:  .asciz "\r\n"

/*
 * Enter the labels in Global Entry Table (GOT).
 * Switch to .got2 section.
 */
	START_GOT
	GOT_ENTRY(err_str)
	GOT_ENTRY(warn_str)
	GOT_ENTRY(end_str)
	END_GOT

/*
 * Switch  back to .text section.
 */
	.text

/****************************************
 ****************************************
 ********    LED register test   ********
 ****************************************
 ***************************************/
test_led:
	/* save the return info on stack */
	mflr	r0			/* Get link register */
	stwu	r1, -12(r1)		/* Save back chain and move SP */
	stw	r0, +16(r1)		/* Save link register */
	stw	r4, +8(r1)		/* save R4 */

	WATCHDOG_RESET        		/* Reset the watchdog */

	addi    r3, 0, ERR_FF		/* first test value is ffff */
	addi	r4, r3, 0		/* save copy of pattern */
	bl	set_led			/* store first test value */
	bl	get_led			/* read it back */
	xor.	r4, r4, r3		/* compare to original */
#if defined(CONFIG_W7OLMC)
	andi.   r4, r4, 0x00ff		/* lmc has 8 bits */
#else
	andi.   r4, r4, 0xffff		/* lmg has 16 bits */
#endif
	beq     LED2			/* next test */
	addi    r3, 0, ERR_LED		/* error code = 1 */
	bl	log_err			/* display error and halt */
LED2:	addi    r3, 0, ERR_00		/* 2nd test value is 0000 */
	addi	r4, r3, 0		/* save copy of pattern */
	bl	set_led			/* store first test value */
	bl	get_led			/* read it back */
	xor.	r4, r4, r3		/* compare to original */
#if defined(CONFIG_W7OLMC)
	andi.   r4, r4, 0x00ff		/* lmc has 8 bits */
#else
	andi.   r4, r4, 0xffff		/* lmg has 16 bits */
#endif
	beq     LED3			/* next test */
	addi    r3, 0, ERR_LED		/* error code = 1 */
	bl	log_err			/* display error and halt */

LED3:	/* restore stack and return */
	lwz	r0, +16(r1)		/* Get saved link register */
	mtlr	r0			/* Restore link register */
	lwz	r4, +8(r1)		/* restore r4 */
	addi	r1, r1, +12		/* Remove frame from stack */
	blr				/* Return to calling function */

/****************************************
 ****************************************
 ********     SDRAM TESTS        ********
 ****************************************
 ***************************************/
test_sdram:
	/* called with mem size in r3 */
	/* save the return info on stack */
	mflr	r0			/* Get link register */
	stwu	r1, -16(r1)		/* Save back chain and move SP */
	stw	r0, +20(r1)		/* Save link register */
	stmw	r30, +8(r1)		/* save R30,R31 */
					/* r30 is log2(mem size) */
					/* r31 is mem size */

	/* take log2 of total mem size */
	addi	r31, r3, 0		/* save total mem size */
	addi	r30, 0, 0		/* clear r30 */
l2_loop:
	srwi.	r31, r31, 1		/* shift right 1 */
	addi	r30, r30, 1		/* count shifts */
	bne	l2_loop			/* loop till done */
	addi	r30, r30, -1		/* correct for over count */
	addi	r31, r3, 0		/* save original size */

	/* now kick the dog and test the mem */
	WATCHDOG_RESET        		/* Reset the watchdog */
	bl	Data_Buster		/* test crossed/shorted data lines */
	addi	r3, r30, 0		/* get log2(memsize) */
	addi	r4, r31, 0		/* get memsize */
	bl	Ghost_Buster		/* test crossed/shorted addr lines */
	addi	r3, r31, 0		/* get mem size */
	bl	Bit_Buster		/* check for bad internal bits */

	/* restore stack and return */
	lmw	r30, +8(r1)		/* Restore r30, r31 */
	lwz	r0, +20(r1)		/* Get saved link register */
	mtlr	r0			/* Restore link register */
	addi	r1, r1, +16		/* Remove frame from stack */
	blr				/* Return to calling function */


/****************************************
 ********  sdram data bus test   ********
 ***************************************/
Data_Buster:
	/* save the return info on stack */
	mflr	r0			/* Get link register */
	stwu	r1, -24(r1)		/* Save back chain and move SP */
	stw	r0, +28(r1)		/* Save link register */
	stmw	r28, 8(r1)		/* save r28 - r31 on stack */
					/* r31 i/o register */
					/* r30 sdram base address */
					/* r29 5555 syndrom */
					/* r28 aaaa syndrom */

	/* set up led register for this test */
	addi    r3, 0, ERR_RAMG		/* set led code to 1 */
	bl	log_stat		/* store test value */
	/* now test the dram data bus */
	xor	r30, r30, r30		/* load r30 with base addr of sdram */
	addis	r31, 0, 0x5555		/* load r31 with test value */
	ori	r31, r31, 0x5555
	stw	r31,0(r30)		/* sto the value */
	lwz	r29,0(r30)		/* read it back */
	xor	r29,r31,r29		/* compare it to original */
	addis	r31, 0, 0xaaaa		/* load r31 with test value */
	ori	r31, r31, 0xaaaa
	stw	r31,0(r30)		/* sto the value */
	lwz	r28,0(r30)		/* read it back */
	xor	r28,r31,r28		/* compare it to original */
	or	r3,r28,r29		/* or together both error terms */
	/*
	 * Now that we have the error bits,
	 * we have to decide which part they are in.
	 */
	bl	get_idx			/* r5 is now index to error */
	addi	r3, r3, ERR_RAMG
	cmpwi	r3, ERR_RAMG		/* check for errors */
	beq	db_done			/* skip if no errors */
	bl	log_err			/* log the error */

db_done:
	lmw	r28, 8(r1)		/* restore r28 - r31 from stack */
	lwz	r0, +28(r1)		/* Get saved link register */
	addi	r1, r1, +24		/* Remove frame from stack */
	mtlr	r0			/* Restore link register */
	blr				/* Return to calling function */


/****************************************************
 ********  test for address ghosting in dram ********
 ***************************************************/

Ghost_Buster:
	/* save the return info on stack */
	mflr	r0			/* Get link register */
	stwu	r1, -36(r1)		/* Save back chain and move SP */
	stw	r0, +40(r1)		/* Save link register */
	stmw	r25, 8(r1)		/* save r25 - r31 on stack */
					/* r31 = scratch register */
					/* r30 is main referance loop counter,
					   0 to 23 */
					/* r29 is ghost loop count, 0 to 22 */
					/* r28 is referance address */
					/* r27 is ghost address */
					/* r26 is log2 (mem size) =
					     number of byte addr bits */
					/* r25 is mem size */

	/* save the log2(mem size) and mem size */
	addi	r26, r3, 0		/* r26 is number of byte addr bits */
	addi	r25, r4, 0		/* r25 is mem size in bytes */

	/* set the leds for address ghost test */
	addi	r3, 0, ERR_ADDG
	bl	set_led

	/* first fill memory with zeros */
	srwi	r31, r25, 2		/* convert bytes to longs */
	mtctr	r31			/* setup byte counter */
	addi	r28, 0, 0		/* start at address at 0 */
	addi	r31, 0, 0		/* data value = 0 */
clr_loop:
	stw	r31, 0(r28)		/* Store zero value */
	addi	r28, r28, 4		/* Increment to next word */
	andi.	r27, r28, 0xffff	/* check for 2^16 loops */
	bne	clr_skip		/* if not there, then skip */
	WATCHDOG_RESET   		/* kick the dog every now and then */
clr_skip:
	bdnz	clr_loop		/* Round and round... */

	/* now do main test */
	addi	r30, 0, 0		/* start referance counter at 0 */
outside:
	/*
	 * Calculate the referance address
	 *   the referance address is calculated by setting the (r30-1)
	 *   bit of the base address
	 * when r30=0, the referance address is the base address.
	 * thus the sequence 0,1,2,4,8,..,2^(n-1)
	 * setting the bit is done with the following shift functions.
	 */
	WATCHDOG_RESET   		/* Reset the watchdog */

	addi	r31, 0, 1		/* r31 = 1 */
	slw	r28, r31, r30		/* set bit coresponding to loop cnt */
	srwi	r28, r28, 1		/* then shift it right one so  */
					/*   we start at location 0 */
	/* fill referance address with Fs */
	addi	r31, 0, 0x00ff		/* r31 = one byte of set bits */
	stb     r31,0(r28)		/* save ff in referance address */

        /* ghost (inner) loop, now check all posible ghosted addresses */
	addi	r29, 0, 0		/* start ghosted loop counter at 0 */
inside:
	/*
	 * Calculate the ghost address by flipping one
	 *  bit of referance address.  This gives the
	 *  sequence 1,2,4,8,...,2^(n-1)
	 */
	addi	r31, 0, 1		/* r31 = 1 */
	slw     r27, r31, r29		/* set  bit coresponding to loop cnt */
	xor	r27, r28, r27		/* ghost address = ref addr with
					     bit flipped*/

	/* now check for ghosting */
	lbz     r31,0(r27)		/* get content of ghost addr */
	cmpwi   r31, 0			/* compare read value to 0 */
	bne	Casper			/*   we found a ghost! */

	/* now close ghost ( inner ) loop */
	addi 	r29, r29, 1		/* increment inner loop counter */
	cmpw 	r29, r26		/* check for last inner loop */
	blt		inside		/* do more inner loops */

	/* now close referance ( outer ) loop */
	addi 	r31, 0, 0 		/* r31 = zero */
	stb	r31, 0(28)		/* zero out the altered address loc. */
	/*
	 * Increment and check for end, count is zero based.
	 * With the ble, this gives us one more loops than
	 * address bits for sequence 0,1,2,4,8,...2^(n-1)
	*/
	addi 	r30, r30, 1		/* increment outer loop counter */
	cmpw 	r30, r26		/* check for last inner loop */
	ble	outside			/* do more outer loops */

	/* were done, lets go home */
	b	gb_done
Casper:					/* we found a ghost !! */
	addi	r3, 0, ERR_ADDF		/* get indexed error message */
	bl	log_err			/* log error led error code */
gb_done: /*  pack your bags, and go home */
        lmw     r25, 8(r1)              /* restore r25 - r31 from stack */
        lwz     r0, +40(r1)             /* Get saved link register */
        addi    r1, r1, +36             /* Remove frame from stack */
        mtlr    r0                      /* Restore link register */
        blr                             /* Return to calling function */

/****************************************************
 ********      SDRAM data fill tests       **********
 ***************************************************/
Bit_Buster:
	/* called with mem size in r3 */
	/* save the return info on stack */
	mflr	r0			/* Get link register */
	stwu	r1, -16(r1)		/* Save back chain and move SP */
	stw	r0, +20(r1)		/* Save link register */
	stw	r4, +8(r1)		/* save R4 */
	stw	r5, +12(r1)		/* save r5 */

	addis	r5, r3, 0		/* save mem size */

	/* Test 55555555 */
	addi	r3, 0, ERR_R55G		/* set up error code in case we fail */
	bl	log_stat		/* store test value */
	addis	r4, 0, 0x5555
	ori	r4, r4, 0x5555
	bl	fill_test

	/* Test aaaaaaaa  */
	addi	r3, 0, ERR_RAAG		/* set up error code in case we fail */
	bl	log_stat		/* store test value */
	addis	r4, 0, 0xAAAA
	ori	r4, r4, 0xAAAA
	bl	fill_test

	/* Test 00000000  */
	addi	r3, 0, ERR_R00G		/* set up error code in case we fail */
	bl	log_stat		/* store test value */
	addis	r4, 0, 0
	ori	r4, r4, 0
	bl	fill_test

	/* restore stack and return */
	lwz	r5, +12(r1)		/* restore r4 */
	lwz	r4, +8(r1)		/* restore r4 */
	lwz	r0, +20(r1)		/* Get saved link register */
	addi	r1, r1, +16		/* Remove frame from stack */
	mtlr	r0			/* Restore link register */
	blr				/* Return to calling function */