u-boot/board/jse/init.S
Stefan Roese bbeff30cbd ppc4xx: Remove superfluous dram_init() call or replace it by initdram()
Historically the 405 U-Boot port had a dram_init() call in early init
stage. This function was still called from start.S and most of the time
coded in assembler. This is not needed anymore (since a long time) and
boards should implement the common initdram() function in C instead.

This patch now removed the dram_init() call from start.S and removes the
empty implementations that are scattered through most of the 405 board
ports. Some older board ports really implement this dram_init() though.
These are:

csb272
csb472
ERIC
EXBITGEN
W7OLMC
W7OLMG

I changed those boards to call this assembler dram_init() function now
from their board specific initdram() instead. This *should* work, but please
test again on those platforms. And it is perhaps a good idea that those
boards use some common 405 SDRAM initialization code from cpu/ppc4xx at
some time. So further patches welcome here.

Signed-off-by: Stefan Roese <sr@denx.de>
2008-06-03 20:22:19 +02:00

95 lines
3.9 KiB
ArmAsm

/*------------------------------------------------------------------------+ */
/* */
/* This source code has been made available to you by IBM on an AS-IS */
/* basis. Anyone receiving this source is licensed under IBM */
/* copyrights to use it in any way he or she deems fit, including */
/* copying it, modifying it, compiling it, and redistributing it either */
/* with or without modifications. No license under IBM patents or */
/* patent applications is to be implied by the copyright license. */
/* */
/* Any user of this software should understand that IBM cannot provide */
/* technical support for this software and will not be responsible for */
/* any consequences resulting from the use of this software. */
/* */
/* Any person who transfers this source code or any derivative work */
/* must include the IBM copyright notice, this paragraph, and the */
/* preceding two paragraphs in the transferred software. */
/* */
/* COPYRIGHT I B M CORPORATION 1995 */
/* LICENSED MATERIAL - PROGRAM PROPERTY OF I B M */
/*------------------------------------------------------------------------- */
/*------------------------------------------------------------------------- */
/* 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. */
/* */
/* */
/* The layout for the PEI JSE board: */
/* Bank 0 - Flash and SRAM */
/* Bank 1 - SystemACE */
/* Bank 2 - not used */
/* Bank 3 - not used */
/* Bank 4 - not used */
/* Bank 5 - not used */
/* Bank 6 - not used */
/* Bank 7 - not used */
/*------------------------------------------------------------------------- */
#include <ppc4xx.h>
#include <ppc_asm.tmpl>
#include <ppc_defs.h>
#include <asm/cache.h>
#include <asm/mmu.h>
#define cpc0_cr0 0xB1
.globl ext_bus_cntlr_init
ext_bus_cntlr_init:
mflr r4 /* save link register */
bl ..getAddr
..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) */
..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 */
/*----------------------------------------------------------------- */
/* Delay to ensure all accesses to ROM are complete before changing */
/* bank 0 timings. 200usec should be enough. */
/* 200,000,000 (cycles/sec) X .000200 (sec) = 0x9C40 cycles */
/*----------------------------------------------------------------- */
addis r3,0,0x0
ori r3,r3,0xA000 /* ensure 200usec have passed since reset */
mtctr r3
..spinlp:
bdnz ..spinlp /* spin loop */
/*----------------------------------------------------------------- */
/* Memory Bank 0 (Flash) initialization */
/*----------------------------------------------------------------- */
addi r4,0,pb0ap
mtdcr ebccfga,r4
addis r4,0,0x9B01
ori r4,r4,0x5480
mtdcr ebccfgd,r4
addi r4,0,pb0cr
mtdcr ebccfga,r4
addis r4,0,0xFFF1 /* BAS=0xFFF,BS=0x0(1MB),BU=0x3(R/W), */
ori r4,r4,0x8000 /* BW=0x0( 8 bits) */
mtdcr ebccfgd,r4
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