blob: 3ba0247f5dd3e91331730d66d55ef8197547ba74 [file] [log] [blame]
* arch/ppc/boot/simple/head.S
* Initial board bringup code for many different boards.
* Author: Tom Rini
* Derived from arch/ppc/boot/prep/head.S (Cort Dougan, many others).
* 2001-2003 (c) MontaVista, Software, Inc. This file is licensed under
* the terms of the GNU General Public License version 2. This program
* is licensed "as is" without any warranty of any kind, whether express
* or implied.
#include <linux/config.h>
#include <asm/processor.h>
#include <asm/cache.h>
#include <asm/ppc_asm.h>
* Begin at some arbitrary location in RAM or Flash
* Initialize core registers
* Configure memory controller (Not executing from RAM)
* Move the boot code to the link address (8M)
* Setup C stack
* Initialize UART
* Decompress the kernel to 0x0
* Jump to the kernel entry
.globl start
bl start_
/* The IBM OpenBIOS bootroms know that the address of the bootrom
* read only structure is 4 bytes after _start.
.long 0x62726f6d # structure ID - "brom"
.long 0x5f726f00 # - "_ro\0"
.long 1 # structure version
.long bootrom_cmdline # address of *bootrom_cmdline
/* We have some really bad firmware. We must disable the L1
* icache/dcache now or the board won't boot.
li r4,0x0000
mtspr HID0,r4
#if defined(CONFIG_MBX) || defined(CONFIG_RPX6)
mr r29,r3 /* On the MBX860, r3 is the board info pointer.
* On the RPXSUPER, r3 points to the
* NVRAM configuration keys.
mflr r3 /* Save our actual starting address. */
/* The following functions we call must not modify r3 or r4.....
#ifdef CONFIG_6xx
bl disable_6xx_mmu
bl disable_6xx_l1cache
#if defined(CONFIG_FORCE) || defined(CONFIG_K2) || defined(CONFIG_EV64260)
bl _setup_L2CR
/* If 745x, turn off L3CR as well */
mfspr r8,PVR
srwi r8,r8,16
cmpli cr0,r8,0x8000 /* 7450 */
cmpli cr1,r8,0x8001 /* 7455 */
cmpli cr2,r8,0x8002 /* 7457 */
cror 4*cr0+eq,4*cr0+eq,4*cr1+eq /* Now test if any are true. */
cror 4*cr0+eq,4*cr0+eq,4*cr2+eq
beql _setup_L3CR
#ifdef CONFIG_8xx
mfmsr r8 /* Turn off interrupts */
li r9,0
ori r9,r9,MSR_EE
andc r8,r8,r9
mtmsr r8
/* We do this because some boot roms don't initialize the
* processor correctly. Don't do this if you want to debug
* using a BDM device.
li r4,0 /* Zero DER to prevent FRZ */
mtspr SPRN_DER,r4
/* All of this Redwood 4 stuff will soon disappear when the
* boot rom is straightened out.
mr r29, r3 /* Easier than changing the other code */
bl HdwInit
mr r3, r29
#if defined(CONFIG_MBX) || defined(CONFIG_RPX6)
mr r4,r29 /* put the board info pointer where the relocate
* routine will find it
#ifdef CONFIG_EV64260
/* Move 64260's base regs & CS window for external UART */
bl ev64260_init
/* Get the load address.
subi r3, r3, 4 /* Get the actual IP, not NIP */
b relocate