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https://github.com/AsahiLinux/u-boot
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726 lines
24 KiB
ArmAsm
726 lines
24 KiB
ArmAsm
/*
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* (C) Copyright 2001
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* Bill Hunter, Wave 7 Optics, william.hunter@mediaone.net
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* and
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* Erik Theisen, Wave 7 Optics, etheisen@mindspring.com
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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/*
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* Description:
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* Routine to exercise memory for the bringing up of our boards.
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*/
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#include <config.h>
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#include <asm/ppc4xx.h>
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#define _LINUX_CONFIG_H 1 /* avoid reading Linux autoconf.h file */
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#include <ppc_asm.tmpl>
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#include <ppc_defs.h>
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#include <asm/cache.h>
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#include <asm/mmu.h>
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#include <watchdog.h>
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#include "errors.h"
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#define _ASMLANGUAGE
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.globl test_sdram
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.globl test_led
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.globl log_stat
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.globl log_warn
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.globl log_err
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.globl temp_uart_init
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.globl post_puts
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.globl disp_hex
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/*****************************************************
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******* Text Strings for low level printing ******
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******* In section got2 *******
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*****************************************************/
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/*
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* Define the text strings for errors and warnings.
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* Switch to .data section.
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*/
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.section ".data"
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err_str: .asciz "*** POST ERROR = "
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warn_str: .asciz "*** POST WARNING = "
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end_str: .asciz "\r\n"
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/*
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* Enter the labels in Global Entry Table (GOT).
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* Switch to .got2 section.
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*/
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START_GOT
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GOT_ENTRY(err_str)
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GOT_ENTRY(warn_str)
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GOT_ENTRY(end_str)
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END_GOT
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/*
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* Switch back to .text section.
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*/
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.text
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/****************************************
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****************************************
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******** LED register test ********
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****************************************
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***************************************/
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test_led:
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/* save the return info on stack */
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mflr r0 /* Get link register */
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stwu r1, -12(r1) /* Save back chain and move SP */
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stw r0, +16(r1) /* Save link register */
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stw r4, +8(r1) /* save R4 */
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WATCHDOG_RESET /* Reset the watchdog */
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addi r3, 0, ERR_FF /* first test value is ffff */
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addi r4, r3, 0 /* save copy of pattern */
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bl set_led /* store first test value */
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bl get_led /* read it back */
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xor. r4, r4, r3 /* compare to original */
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#if defined(CONFIG_W7OLMC)
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andi. r4, r4, 0x00ff /* lmc has 8 bits */
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#else
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andi. r4, r4, 0xffff /* lmg has 16 bits */
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#endif
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beq LED2 /* next test */
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addi r3, 0, ERR_LED /* error code = 1 */
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bl log_err /* display error and halt */
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LED2: addi r3, 0, ERR_00 /* 2nd test value is 0000 */
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addi r4, r3, 0 /* save copy of pattern */
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bl set_led /* store first test value */
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bl get_led /* read it back */
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xor. r4, r4, r3 /* compare to original */
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#if defined(CONFIG_W7OLMC)
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andi. r4, r4, 0x00ff /* lmc has 8 bits */
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#else
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andi. r4, r4, 0xffff /* lmg has 16 bits */
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#endif
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beq LED3 /* next test */
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addi r3, 0, ERR_LED /* error code = 1 */
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bl log_err /* display error and halt */
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LED3: /* restore stack and return */
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lwz r0, +16(r1) /* Get saved link register */
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mtlr r0 /* Restore link register */
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lwz r4, +8(r1) /* restore r4 */
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addi r1, r1, +12 /* Remove frame from stack */
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blr /* Return to calling function */
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/****************************************
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****************************************
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******** SDRAM TESTS ********
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****************************************
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***************************************/
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test_sdram:
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/* called with mem size in r3 */
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/* save the return info on stack */
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mflr r0 /* Get link register */
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stwu r1, -16(r1) /* Save back chain and move SP */
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stw r0, +20(r1) /* Save link register */
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stmw r30, +8(r1) /* save R30,R31 */
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/* r30 is log2(mem size) */
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/* r31 is mem size */
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/* take log2 of total mem size */
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addi r31, r3, 0 /* save total mem size */
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addi r30, 0, 0 /* clear r30 */
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l2_loop:
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srwi. r31, r31, 1 /* shift right 1 */
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addi r30, r30, 1 /* count shifts */
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bne l2_loop /* loop till done */
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addi r30, r30, -1 /* correct for over count */
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addi r31, r3, 0 /* save original size */
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/* now kick the dog and test the mem */
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WATCHDOG_RESET /* Reset the watchdog */
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bl Data_Buster /* test crossed/shorted data lines */
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addi r3, r30, 0 /* get log2(memsize) */
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addi r4, r31, 0 /* get memsize */
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bl Ghost_Buster /* test crossed/shorted addr lines */
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addi r3, r31, 0 /* get mem size */
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bl Bit_Buster /* check for bad internal bits */
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/* restore stack and return */
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lmw r30, +8(r1) /* Restore r30, r31 */
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lwz r0, +20(r1) /* Get saved link register */
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mtlr r0 /* Restore link register */
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addi r1, r1, +16 /* Remove frame from stack */
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blr /* Return to calling function */
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/****************************************
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******** sdram data bus test ********
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***************************************/
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Data_Buster:
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/* save the return info on stack */
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mflr r0 /* Get link register */
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stwu r1, -24(r1) /* Save back chain and move SP */
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stw r0, +28(r1) /* Save link register */
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stmw r28, 8(r1) /* save r28 - r31 on stack */
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/* r31 i/o register */
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/* r30 sdram base address */
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/* r29 5555 syndrom */
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/* r28 aaaa syndrom */
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/* set up led register for this test */
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addi r3, 0, ERR_RAMG /* set led code to 1 */
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bl log_stat /* store test value */
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/* now test the dram data bus */
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xor r30, r30, r30 /* load r30 with base addr of sdram */
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addis r31, 0, 0x5555 /* load r31 with test value */
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ori r31, r31, 0x5555
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stw r31,0(r30) /* sto the value */
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lwz r29,0(r30) /* read it back */
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xor r29,r31,r29 /* compare it to original */
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addis r31, 0, 0xaaaa /* load r31 with test value */
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ori r31, r31, 0xaaaa
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stw r31,0(r30) /* sto the value */
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lwz r28,0(r30) /* read it back */
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xor r28,r31,r28 /* compare it to original */
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or r3,r28,r29 /* or together both error terms */
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/*
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* Now that we have the error bits,
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* we have to decide which part they are in.
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*/
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bl get_idx /* r5 is now index to error */
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addi r3, r3, ERR_RAMG
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cmpwi r3, ERR_RAMG /* check for errors */
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beq db_done /* skip if no errors */
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bl log_err /* log the error */
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db_done:
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lmw r28, 8(r1) /* restore r28 - r31 from stack */
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lwz r0, +28(r1) /* Get saved link register */
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addi r1, r1, +24 /* Remove frame from stack */
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mtlr r0 /* Restore link register */
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blr /* Return to calling function */
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/****************************************************
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******** test for address ghosting in dram ********
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***************************************************/
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Ghost_Buster:
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/* save the return info on stack */
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mflr r0 /* Get link register */
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stwu r1, -36(r1) /* Save back chain and move SP */
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stw r0, +40(r1) /* Save link register */
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stmw r25, 8(r1) /* save r25 - r31 on stack */
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/* r31 = scratch register */
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/* r30 is main referance loop counter,
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0 to 23 */
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/* r29 is ghost loop count, 0 to 22 */
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/* r28 is referance address */
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/* r27 is ghost address */
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/* r26 is log2 (mem size) =
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number of byte addr bits */
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/* r25 is mem size */
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/* save the log2(mem size) and mem size */
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addi r26, r3, 0 /* r26 is number of byte addr bits */
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addi r25, r4, 0 /* r25 is mem size in bytes */
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/* set the leds for address ghost test */
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addi r3, 0, ERR_ADDG
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bl set_led
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/* first fill memory with zeros */
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srwi r31, r25, 2 /* convert bytes to longs */
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mtctr r31 /* setup byte counter */
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addi r28, 0, 0 /* start at address at 0 */
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addi r31, 0, 0 /* data value = 0 */
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clr_loop:
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stw r31, 0(r28) /* Store zero value */
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addi r28, r28, 4 /* Increment to next word */
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andi. r27, r28, 0xffff /* check for 2^16 loops */
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bne clr_skip /* if not there, then skip */
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WATCHDOG_RESET /* kick the dog every now and then */
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clr_skip:
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bdnz clr_loop /* Round and round... */
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/* now do main test */
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addi r30, 0, 0 /* start referance counter at 0 */
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outside:
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/*
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* Calculate the referance address
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* the referance address is calculated by setting the (r30-1)
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* bit of the base address
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* when r30=0, the referance address is the base address.
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* thus the sequence 0,1,2,4,8,..,2^(n-1)
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* setting the bit is done with the following shift functions.
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*/
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WATCHDOG_RESET /* Reset the watchdog */
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addi r31, 0, 1 /* r31 = 1 */
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slw r28, r31, r30 /* set bit coresponding to loop cnt */
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srwi r28, r28, 1 /* then shift it right one so */
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/* we start at location 0 */
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/* fill referance address with Fs */
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addi r31, 0, 0x00ff /* r31 = one byte of set bits */
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stb r31,0(r28) /* save ff in referance address */
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/* ghost (inner) loop, now check all posible ghosted addresses */
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addi r29, 0, 0 /* start ghosted loop counter at 0 */
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inside:
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/*
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* Calculate the ghost address by flipping one
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* bit of referance address. This gives the
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* sequence 1,2,4,8,...,2^(n-1)
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*/
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addi r31, 0, 1 /* r31 = 1 */
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slw r27, r31, r29 /* set bit coresponding to loop cnt */
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xor r27, r28, r27 /* ghost address = ref addr with
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bit flipped*/
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/* now check for ghosting */
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lbz r31,0(r27) /* get content of ghost addr */
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cmpwi r31, 0 /* compare read value to 0 */
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bne Casper /* we found a ghost! */
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/* now close ghost ( inner ) loop */
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addi r29, r29, 1 /* increment inner loop counter */
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cmpw r29, r26 /* check for last inner loop */
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blt inside /* do more inner loops */
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/* now close referance ( outer ) loop */
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addi r31, 0, 0 /* r31 = zero */
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stb r31, 0(28) /* zero out the altered address loc. */
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/*
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* Increment and check for end, count is zero based.
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* With the ble, this gives us one more loops than
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* address bits for sequence 0,1,2,4,8,...2^(n-1)
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*/
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addi r30, r30, 1 /* increment outer loop counter */
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cmpw r30, r26 /* check for last inner loop */
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ble outside /* do more outer loops */
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/* were done, lets go home */
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b gb_done
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Casper: /* we found a ghost !! */
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addi r3, 0, ERR_ADDF /* get indexed error message */
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bl log_err /* log error led error code */
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gb_done: /* pack your bags, and go home */
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lmw r25, 8(r1) /* restore r25 - r31 from stack */
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lwz r0, +40(r1) /* Get saved link register */
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addi r1, r1, +36 /* Remove frame from stack */
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mtlr r0 /* Restore link register */
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blr /* Return to calling function */
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/****************************************************
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******** SDRAM data fill tests **********
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***************************************************/
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Bit_Buster:
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/* called with mem size in r3 */
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/* save the return info on stack */
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mflr r0 /* Get link register */
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stwu r1, -16(r1) /* Save back chain and move SP */
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stw r0, +20(r1) /* Save link register */
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stw r4, +8(r1) /* save R4 */
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stw r5, +12(r1) /* save r5 */
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addis r5, r3, 0 /* save mem size */
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/* Test 55555555 */
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addi r3, 0, ERR_R55G /* set up error code in case we fail */
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bl log_stat /* store test value */
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addis r4, 0, 0x5555
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ori r4, r4, 0x5555
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bl fill_test
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/* Test aaaaaaaa */
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addi r3, 0, ERR_RAAG /* set up error code in case we fail */
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bl log_stat /* store test value */
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addis r4, 0, 0xAAAA
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ori r4, r4, 0xAAAA
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bl fill_test
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/* Test 00000000 */
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addi r3, 0, ERR_R00G /* set up error code in case we fail */
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bl log_stat /* store test value */
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addis r4, 0, 0
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ori r4, r4, 0
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bl fill_test
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/* restore stack and return */
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lwz r5, +12(r1) /* restore r4 */
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lwz r4, +8(r1) /* restore r4 */
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lwz r0, +20(r1) /* Get saved link register */
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addi r1, r1, +16 /* Remove frame from stack */
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mtlr r0 /* Restore link register */
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blr /* Return to calling function */
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/****************************************************
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******** fill test ********
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***************************************************/
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/* tests memory by filling with value, and reading back */
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/* r5 = Size of memory in bytes */
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/* r4 = Value to write */
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/* r3 = Error code */
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fill_test:
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mflr r0 /* Get link register */
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stwu r1, -32(r1) /* Save back chain and move SP */
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stw r0, +36(r1) /* Save link register */
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stmw r27, 8(r1) /* save r27 - r31 on stack */
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/* r31 - scratch register */
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/* r30 - memory address */
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mr r27, r3
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mr r28, r4
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mr r29, r5
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WATCHDOG_RESET /* Reset the watchdog */
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/* first fill memory with Value */
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srawi r31, r29, 2 /* convert bytes to longs */
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mtctr r31 /* setup counter */
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addi r30, 0, 0 /* Make r30 = addr 0 */
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ft_0: stw r28, 0(r30) /* Store value */
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addi r30, r30, 4 /* Increment to next word */
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andi. r31, r30, 0xffff /* check for 2^16 loops */
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bne ft_0a /* if not there, then skip */
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WATCHDOG_RESET /* kick the dog every now and then */
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ft_0a: bdnz ft_0 /* Round and round... */
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WATCHDOG_RESET /* Reset the watchdog */
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/* Now confirm Value is in memory */
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srawi r31, r29, 2 /* convert bytes to longs */
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mtctr r31 /* setup counter */
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addi r30, 0, 0 /* Make r30 = addr 0 */
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ft_1: lwz r31, 0(r30) /* get value from memory */
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xor. r31, r31, r28 /* Writen = Read ? */
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bne ft_err /* If bad, than halt */
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addi r30, r30, 4 /* Increment to next word */
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andi. r31, r30, 0xffff /* check for 2^16 loops*/
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bne ft_1a /* if not there, then skip */
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WATCHDOG_RESET /* kick the dog every now and then */
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ft_1a: bdnz ft_1 /* Round and round... */
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WATCHDOG_RESET /* Reset the watchdog */
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b fill_done /* restore and return */
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ft_err: addi r29, r27, 0 /* save current led code */
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addi r27, r31, 0 /* get pattern in r27 */
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bl get_idx /* get index from r27 */
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add r27, r27, r29 /* add index to old led code */
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bl log_err /* output led err code, halt CPU */
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fill_done:
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lmw r27, 8(r1) /* restore r27 - r31 from stack */
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lwz r0, +36(r1) /* Get saved link register */
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addi r1, r1, +32 /* Remove frame from stack */
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mtlr r0 /* Restore link register */
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blr /* Return to calling function */
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/****************************************************
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******* get error index from r3 pattern ********
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***************************************************/
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get_idx: /* r3 = (MSW(r3) !=0)*2 +
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(LSW(r3) !=0) */
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/* save the return info on stack */
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mflr r0 /* Get link register */
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stwu r1, -12(r1) /* Save back chain and move SP */
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stw r0, +16(r1) /* Save link register */
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stw r4, +8(r1) /* save R4 */
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andi. r4, r3, 0xffff /* check for lower bits */
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beq gi2 /* skip if no bits set */
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andis. r4, r3, 0xffff /* check for upper bits */
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beq gi3 /* skip if no bits set */
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addi r3, 0, 3 /* both upper and lower bits set */
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b gi_done
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gi2: andis. r4, r3, 0xffff /* check for upper bits*/
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beq gi4 /* skip if no bits set */
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addi r3, 0, 2 /* only upper bits set */
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b gi_done
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gi3: addi r3, 0, 1 /* only lower bits set */
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b gi_done
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gi4: addi r3, 0, 0 /* no bits set */
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gi_done:
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/* restore stack and return */
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lwz r0, +16(r1) /* Get saved link register */
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mtlr r0 /* Restore link register */
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lwz r4, +8(r1) /* restore r4 */
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addi r1, r1, +12 /* Remove frame from stack */
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blr /* Return to calling function */
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/****************************************************
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******** set LED to R5 and hang ********
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***************************************************/
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log_stat: /* output a led code and continue */
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set_led:
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/* save the return info on stack */
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mflr r0 /* Get link register */
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stwu r1, -12(r1) /* Save back chain and move SP */
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stw r0, +16(r1) /* Save link register */
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stw r4, +8(r1) /* save R4 */
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addis r4, 0, 0xfe00 /* LED buffer is at 0xfe000000 */
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#if defined(CONFIG_W7OLMG) /* only on gateway, invert outputs */
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xori r3,r3, 0xffff /* complement led code, active low */
|
|
sth r3, 0(r4) /* store first test value */
|
|
xori r3,r3, 0xffff /* complement led code, active low */
|
|
#else /* if not gateway, then don't invert */
|
|
sth r3, 0(r4) /* store first test value */
|
|
#endif
|
|
|
|
/* 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 */
|
|
|
|
get_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 */
|
|
|
|
addis r4, 0, 0xfe00 /* LED buffer is at 0xfe000000 */
|
|
lhz r3, 0(r4) /* store first test value */
|
|
#if defined(CONFIG_W7OLMG) /* only on gateway, invert inputs */
|
|
xori r3,r3, 0xffff /* complement led code, active low */
|
|
#endif
|
|
|
|
/* 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 */
|
|
|
|
log_err: /* output the error and hang the board ( for now ) */
|
|
/* 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 r3, +8(r1) /* save a copy of error code */
|
|
bl set_led /* set the led pattern */
|
|
GET_GOT /* get GOT address in r14 */
|
|
lwz r3,GOT(err_str) /* get address of string */
|
|
bl post_puts /* output the warning string */
|
|
lwz r3, +8(r1) /* get error code */
|
|
addi r4, 0, 2 /* set disp length to 2 nibbles */
|
|
bl disp_hex /* output the error code */
|
|
lwz r3,GOT(end_str) /* get address of string */
|
|
bl post_puts /* output the warning string */
|
|
halt:
|
|
b halt /* hang */
|
|
|
|
/* restore stack and return */
|
|
lwz r0, +16(r1) /* Get saved link register */
|
|
mtlr r0 /* Restore link register */
|
|
addi r1, r1, +12 /* Remove frame from stack */
|
|
blr /* Return to calling function */
|
|
|
|
log_warn: /* output a warning, then continue with operations */
|
|
/* 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 r3, +8(r1) /* save a copy of error code */
|
|
stw r14, +12(r1) /* save a copy of r14 (used by GOT) */
|
|
|
|
bl set_led /* set the led pattern */
|
|
GET_GOT /* get GOT address in r14 */
|
|
lwz r3,GOT(warn_str) /* get address of string */
|
|
bl post_puts /* output the warning string */
|
|
lwz r3, +8(r1) /* get error code */
|
|
addi r4, 0, 2 /* set disp length to 2 nibbles */
|
|
bl disp_hex /* output the error code */
|
|
lwz r3,GOT(end_str) /* get address of string */
|
|
bl post_puts /* output the warning string */
|
|
|
|
addis r3, 0, 64 /* has a long delay */
|
|
mtctr r3
|
|
log_2:
|
|
WATCHDOG_RESET /* this keeps dog from barking, */
|
|
/* and takes time */
|
|
bdnz log_2 /* loop till time expires */
|
|
|
|
/* restore stack and return */
|
|
lwz r0, +20(r1) /* Get saved link register */
|
|
lwz r14, +12(r1) /* restore r14 */
|
|
mtlr r0 /* Restore link register */
|
|
addi r1, r1, +16 /* Remove frame from stack */
|
|
blr /* Return to calling function */
|
|
|
|
/*******************************************************************
|
|
* temp_uart_init
|
|
* Temporary UART initialization routine
|
|
* Sets up UART0 to run at 9600N81 off of the internal clock.
|
|
* R3-R4 are used.
|
|
******************************************************************/
|
|
temp_uart_init:
|
|
/* save the return info on stack */
|
|
mflr r0 /* Get link register */
|
|
stwu r1, -8(r1) /* Save back chain and move SP */
|
|
stw r0, +12(r1) /* Save link register */
|
|
|
|
addis r3, 0, 0xef60
|
|
ori r3, r3, 0x0303 /* r3 = UART0_LCR */
|
|
addi r4, 0, 0x83 /* n81 format, divisor regs enabled */
|
|
stb r4, 0(r3)
|
|
|
|
/* set baud rate to use internal clock,
|
|
baud = (200e6/16)/31/42 = 9600 */
|
|
|
|
addis r3, 0, 0xef60 /* Address of baud divisor reg */
|
|
ori r3, r3, 0x0300 /* UART0_DLM */
|
|
addi r4, 0, +42 /* uart baud divisor LSB = 93 */
|
|
stb r4, 0(r3) /* baud = (200 /16)/14/93 */
|
|
|
|
addi r3, r3, 0x0001 /* uart baud divisor addr */
|
|
addi r4, 0, 0
|
|
stb r4, 0(r3) /* Divisor Latch MSB = 0 */
|
|
|
|
addis r3, 0, 0xef60
|
|
ori r3, r3, 0x0303 /* r3 = UART0_LCR */
|
|
addi r4, 0, 0x03 /* n81 format, tx/rx regs enabled */
|
|
stb r4, 0(r3)
|
|
|
|
/* output a few line feeds */
|
|
addi r3, 0, '\n' /* load line feed */
|
|
bl post_putc /* output the char */
|
|
addi r3, 0, '\n' /* load line feed */
|
|
bl post_putc /* output the char */
|
|
|
|
/* restore stack and return */
|
|
lwz r0, +12(r1) /* Get saved link register */
|
|
mtlr r0 /* Restore link register */
|
|
addi r1, r1, +8 /* Remove frame from stack */
|
|
blr /* Return to calling function */
|
|
|
|
/**********************************************************************
|
|
** post_putc
|
|
** outputs charactor in R3
|
|
** r3 returns the error code ( -1 if there is an error )
|
|
*********************************************************************/
|
|
|
|
post_putc:
|
|
|
|
/* save the return info on stack */
|
|
mflr r0 /* Get link register */
|
|
stwu r1, -20(r1) /* Save back chain and move SP */
|
|
stw r0, +24(r1) /* Save link register */
|
|
stmw r29, 8(r1) /* save r29 - r31 on stack
|
|
r31 - uart base address
|
|
r30 - delay counter
|
|
r29 - scratch reg */
|
|
|
|
addis r31, 0, 0xef60 /* Point to uart base */
|
|
ori r31, r31, 0x0300
|
|
addis r30, 0, 152 /* Load about 10,000,000 ticks. */
|
|
pputc_lp:
|
|
lbz r29, 5(r31) /* Read Line Status Register */
|
|
andi. r29, r29, 0x20 /* Check THRE status */
|
|
bne thre_set /* Branch if FIFO empty */
|
|
addic. r30, r30, -1 /* Decrement and check if empty. */
|
|
bne pputc_lp /* Try, try again */
|
|
addi r3, 0, -1 /* Load error code for timeout */
|
|
b pputc_done /* Bail out with error code set */
|
|
thre_set:
|
|
stb r3, 0(r31) /* Store character to UART */
|
|
addi r3, 0, 0 /* clear error code */
|
|
pputc_done:
|
|
lmw r29, 8(r1) /*restore r29 - r31 from stack */
|
|
lwz r0, +24(r1) /* Get saved link register */
|
|
addi r1, r1, +20 /* Remove frame from stack */
|
|
mtlr r0 /* Restore link register */
|
|
blr /* Return to calling function */
|
|
|
|
|
|
/****************************************************************
|
|
post_puts
|
|
Accepts a null-terminated string pointed to by R3
|
|
Outputs to the serial port until 0x00 is found.
|
|
r3 returns the error code ( -1 if there is an error )
|
|
*****************************************************************/
|
|
post_puts:
|
|
|
|
/* 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 r31, 8(r1) /* save r31 - char pointer */
|
|
|
|
addi r31, r3, 0 /* move pointer to R31 */
|
|
pputs_nxt:
|
|
lbz r3, 0(r31) /* Get next character */
|
|
addic. r3, r3, 0 /* Check for zero */
|
|
beq pputs_term /* bail out if zero */
|
|
bl post_putc /* output the char */
|
|
addic. r3, r3, 0 /* check for error */
|
|
bne pputs_err
|
|
addi r31, r31, 1 /* point to next char */
|
|
b pputs_nxt /* loop till term */
|
|
pputs_err:
|
|
addi r3, 0, -1 /* set error code */
|
|
b pputs_end /* were outa here */
|
|
pputs_term:
|
|
addi r3, 0, 1 /* set success code */
|
|
/* restore stack and return */
|
|
pputs_end:
|
|
lwz r31, 8(r1) /* restore r27 - r31 from stack */
|
|
lwz r0, +16(r1) /* Get saved link register */
|
|
addi r1, r1, +12 /* Remove frame from stack */
|
|
mtlr r0 /* Restore link register */
|
|
blr /* Return to calling function */
|
|
|
|
|
|
/********************************************************************
|
|
***** disp_hex
|
|
***** Routine to display a hex value from a register.
|
|
***** R3 is value to display
|
|
***** R4 is number of nibbles to display ie 2 for byte 8 for (long)word
|
|
***** Returns -1 in R3 if there is an error ( ie serial port hangs )
|
|
***** Returns 0 in R3 if no error
|
|
*******************************************************************/
|
|
disp_hex:
|
|
/* 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 on stack */
|
|
/* r31 output char */
|
|
/* r30 uart base address */
|
|
addi r30, 0, 8 /* Go through 8 nibbles. */
|
|
addi r31, r3, 0
|
|
pputh_nxt:
|
|
rlwinm r31, r31, 4, 0, 31 /* Rotate next nibble into position */
|
|
andi. r3, r31, 0x0f /* Get nibble. */
|
|
addi r3, r3, 0x30 /* Add zero's ASCII code. */
|
|
cmpwi r3, 0x03a
|
|
blt pputh_out
|
|
addi r3, r3, 0x07 /* 0x27 for lower case. */
|
|
pputh_out:
|
|
cmpw r30, r4
|
|
bgt pputh_skip
|
|
bl post_putc
|
|
addic. r3, r3, 0 /* check for error */
|
|
bne pputh_err
|
|
pputh_skip:
|
|
addic. r30, r30, -1
|
|
bne pputh_nxt
|
|
xor r3, r3, r3 /* Clear error code */
|
|
b pputh_done
|
|
pputh_err:
|
|
addi r3, 0, -1 /* set error code */
|
|
pputh_done:
|
|
/* restore stack and return */
|
|
lmw r30, 8(r1) /* restore r30 - r31 from stack */
|
|
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 */
|