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06bffc6ea5
For some reason the AT91rm9200 lowlevel init writes to a bunch of reserved or read-only addresses. All the boards seem to define the value-to-be-written values as zero ... but they shouldn't actually be writing *anything* there. No documented erratum justifies these accesses. It looks like maybe some pre-release BDI-2000 setup code has been carried along by cargo cult programming since at least late 2004 (per GIT history). Here's a patch disabling what seems to be bogosity. Tested on a csb337; there were no behavioral changes. Signed-off-by: David Brownell <david-b@pacbell.net> on RM9200ek Tested-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
169 lines
4.2 KiB
ArmAsm
169 lines
4.2 KiB
ArmAsm
/*
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* Memory Setup stuff - taken from blob memsetup.S
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*
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* Copyright (C) 1999 2000 2001 Erik Mouw (J.A.K.Mouw@its.tudelft.nl) and
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* Jan-Derk Bakker (J.D.Bakker@its.tudelft.nl)
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*
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* Modified for the at91rm9200dk board by
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* (C) Copyright 2004
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* Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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#include <config.h>
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#include <version.h>
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#ifndef CONFIG_SKIP_LOWLEVEL_INIT
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/*
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* some parameters for the board
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*
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* This is based on rm9200dk.cfg for the BDI2000 from ABATRON which in
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* turn is based on the boot.bin code from ATMEL
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*
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*/
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#include <asm/arch/AT91RM9200.h>
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_MTEXT_BASE:
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#undef START_FROM_MEM
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#ifdef START_FROM_MEM
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.word TEXT_BASE-PHYS_FLASH_1
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#else
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.word TEXT_BASE
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#endif
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.globl lowlevel_init
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lowlevel_init:
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/* Get the CKGR Base Address */
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ldr r1, =AT91C_BASE_CKGR
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/* Main oscillator Enable register */
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#ifdef CONFIG_SYS_USE_MAIN_OSCILLATOR
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ldr r0, =0x0000FF01 /* Enable main oscillator, OSCOUNT = 0xFF */
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#else
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ldr r0, =0x0000FF00 /* Disable main oscillator, OSCOUNT = 0xFF */
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#endif
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str r0, [r1, #AT91C_CKGR_MOR]
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/* Add loop to compensate Main Oscillator startup time */
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ldr r0, =0x00000010
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LoopOsc:
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subs r0, r0, #1
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bhi LoopOsc
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/* memory control configuration */
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/* this isn't very elegant, but what the heck */
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ldr r0, =SMRDATA
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ldr r1, _MTEXT_BASE
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sub r0, r0, r1
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add r2, r0, #80
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0:
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/* the address */
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ldr r1, [r0], #4
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/* the value */
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ldr r3, [r0], #4
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str r3, [r1]
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cmp r2, r0
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bne 0b
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/* delay - this is all done by guess */
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ldr r0, =0x00010000
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/* (vs reading PMC_SR for LOCKA, LOCKB ... or MOSCS earlier) */
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1:
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subs r0, r0, #1
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bhi 1b
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ldr r0, =SMRDATA1
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ldr r1, _MTEXT_BASE
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sub r0, r0, r1
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add r2, r0, #176
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2:
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/* the address */
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ldr r1, [r0], #4
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/* the value */
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ldr r3, [r0], #4
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str r3, [r1]
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cmp r2, r0
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bne 2b
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/* switch from FastBus to Asynchronous clock mode */
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mrc p15, 0, r0, c1, c0, 0
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orr r0, r0, #0xC0000000 @ set bit 31 (iA) and 30 (nF)
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mcr p15, 0, r0, c1, c0, 0
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/* everything is fine now */
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mov pc, lr
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.ltorg
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SMRDATA:
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.word AT91C_EBI_CFGR
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.word CONFIG_SYS_EBI_CFGR_VAL
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.word AT91C_SMC_CSR0
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.word CONFIG_SYS_SMC_CSR0_VAL
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.word AT91C_PLLAR
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.word CONFIG_SYS_PLLAR_VAL
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.word AT91C_PLLBR
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.word CONFIG_SYS_PLLBR_VAL
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.word AT91C_MCKR
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.word CONFIG_SYS_MCKR_VAL
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/* here there's a delay */
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SMRDATA1:
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.word AT91C_PIOC_ASR
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.word CONFIG_SYS_PIOC_ASR_VAL
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.word AT91C_PIOC_BSR
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.word CONFIG_SYS_PIOC_BSR_VAL
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.word AT91C_PIOC_PDR
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.word CONFIG_SYS_PIOC_PDR_VAL
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.word AT91C_EBI_CSA
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.word CONFIG_SYS_EBI_CSA_VAL
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.word AT91C_SDRC_CR
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.word CONFIG_SYS_SDRC_CR_VAL
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.word AT91C_SDRC_MR
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.word CONFIG_SYS_SDRC_MR_VAL
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.word CONFIG_SYS_SDRAM
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.word CONFIG_SYS_SDRAM_VAL
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.word AT91C_SDRC_MR
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.word CONFIG_SYS_SDRC_MR_VAL1
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.word CONFIG_SYS_SDRAM
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.word CONFIG_SYS_SDRAM_VAL
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.word CONFIG_SYS_SDRAM
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.word CONFIG_SYS_SDRAM_VAL
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.word CONFIG_SYS_SDRAM
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.word CONFIG_SYS_SDRAM_VAL
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.word CONFIG_SYS_SDRAM
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.word CONFIG_SYS_SDRAM_VAL
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.word CONFIG_SYS_SDRAM
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.word CONFIG_SYS_SDRAM_VAL
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.word CONFIG_SYS_SDRAM
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.word CONFIG_SYS_SDRAM_VAL
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.word CONFIG_SYS_SDRAM
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.word CONFIG_SYS_SDRAM_VAL
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.word CONFIG_SYS_SDRAM
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.word CONFIG_SYS_SDRAM_VAL
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.word AT91C_SDRC_MR
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.word CONFIG_SYS_SDRC_MR_VAL2
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.word CONFIG_SYS_SDRAM1
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.word CONFIG_SYS_SDRAM_VAL
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.word AT91C_SDRC_TR
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.word CONFIG_SYS_SDRC_TR_VAL
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.word CONFIG_SYS_SDRAM
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.word CONFIG_SYS_SDRAM_VAL
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.word AT91C_SDRC_MR
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.word CONFIG_SYS_SDRC_MR_VAL3
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.word CONFIG_SYS_SDRAM
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.word CONFIG_SYS_SDRAM_VAL
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/* SMRDATA1 is 176 bytes long */
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#endif /* CONFIG_SKIP_LOWLEVEL_INIT */
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