u-boot/board/cray/L1/init.S

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ArmAsm
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/*
* SPDX-License-Identifier: GPL-2.0 IBM-pibs
*/
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/*----------------------------------------------------------------------------- */
/* Function: ext_bus_cntlr_init */
/* Description: Initializes the External Bus Controller for the external */
/* peripherals. IMPORTANT: For pass1 this code must run from */
/* cache since you can not reliably change a peripheral banks */
/* timing register (pbxap) while running code from that bank. */
/* For ex., since we are running from ROM on bank 0, we can NOT */
/* execute the code that modifies bank 0 timings from ROM, so */
/* we run it from cache. */
/* Bank 0 - Flash and SRAM */
/* Bank 1 - NVRAM/RTC */
/* Bank 2 - Keyboard/Mouse controller */
/* Bank 3 - IR controller */
/* Bank 4 - not used */
/* Bank 5 - not used */
/* Bank 6 - not used */
/* Bank 7 - FPGA registers */
/*-----------------------------------------------------------------------------#include <config.h> */
#include <asm/ppc4xx.h>
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#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>
/* CRAY - L1: only nominally a 'walnut', since ext.Bus.Cntlr is all empty */
/* except for #1 which we use for DMA'ing to IOCA-like things, so the */
/* control registers to set that up are determined by what we've */
/* empirically discovered work there. */
.globl ext_bus_cntlr_init
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ext_bus_cntlr_init:
mflr r4 /* save link register */
bl ..getAddr
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..getAddr:
mflr r3 /* get address of ..getAddr */
mtlr r4 /* restore link register */
addi r4,0,14 /* set ctr to 10; used to prefetch */
mtctr r4 /* 10 cache lines to fit this function */
/* in cache (gives us 8x10=80 instrctns) */
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..ebcloop:
icbt r0,r3 /* prefetch cache line for addr in r3 */
addi r3,r3,32 /* move to next cache line */
bdnz ..ebcloop /* continue for 10 cache lines */
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/*------------------------------------------------------------------- */
/* Delay to ensure all accesses to ROM are complete before changing */
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/* bank 0 timings. 200usec should be enough. */
/* 200,000,000 (cycles/sec) X .000200 (sec) = 0x9C40 cycles */
/*------------------------------------------------------------------- */
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addis r3,0,0x0
ori r3,r3,0xA000 /* ensure 200usec have passed since reset */
mtctr r3
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..spinlp:
bdnz ..spinlp /* spin loop */
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/*---------------------------------------------------------------------- */
/* Peripheral Bank 0 (Flash) initialization */
/*---------------------------------------------------------------------- */
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/* 0x7F8FFE80 slowest boot */
addi r4,0,PB1AP
mtdcr EBC0_CFGADDR,r4
addis r4,0,0x9B01
ori r4,r4,0x5480
mtdcr EBC0_CFGDATA,r4
addi r4,0,PB0CR
mtdcr EBC0_CFGADDR,r4
addis r4,0,0xFFC5 /* BAS=0xFFC,BS=0x4(4MB),BU=0x3(R/W), */
ori r4,r4,0x8000 /* BW=0x0( 8 bits) */
mtdcr EBC0_CFGDATA,r4
blr
/*---------------------------------------------------------------------- */
/* Peripheral Bank 1 (NVRAM/RTC) initialization */
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/* CRAY:the L1 has NOT this bank, it is tied to SV2/IOCA/etc/ instead */
/* and we do DMA on it. The ConfigurationRegister part is threfore */
/* almost arbitrary, except that our linux driver needs to know the */
/* address, but it can query, it.. */
/* */
/* The AccessParameter is CRITICAL, */
/* thouch, since it needs to agree with the electrical timings on the */
/* IOCA parallel interface. That value is: 0x0185,4380 */
/* BurstModeEnable BME=0 */
/* TransferWait TWT=3 */
/* ChipSelectOnTiming CSN=1 */
/* OutputEnableOnTimimg OEN=1 */
/* WriteByteEnableOnTiming WBN=1 */
/* WriteByteEnableOffTiming WBF=0 */
/* TransferHold TH=1 */
/* ReadyEnable RE=1 */
/* SampleOnReady SOR=1 */
/* ByteEnableMode BEM=0 */
/* ParityEnable PEN=0 */
/* all reserved bits=0 */
/*---------------------------------------------------------------------- */
/*---------------------------------------------------------------------- */
addi r4,0,PB1AP
mtdcr EBC0_CFGADDR,r4
addis r4,0,0x0185 /* hiword */
ori r4,r4,0x4380 /* loword */
mtdcr EBC0_CFGDATA,r4
addi r4,0,PB1CR
mtdcr EBC0_CFGADDR,r4
addis r4,0,0xF001 /* BAS=0xF00,BS=0x0(1MB),BU=0x3(R/W), */
ori r4,r4,0x8000 /* BW=0x0( 8 bits) */
mtdcr EBC0_CFGDATA,r4
blr