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u-boot/arch/powerpc/cpu/mpc512x/start.S
Po-Yu Chuang 44c6e6591c rename _end to __bss_end__ 
Currently, _end is used for end of BSS section.  We want _end to mean
end of u-boot image, so we rename _end to __bss_end__ first.

Signed-off-by: Po-Yu Chuang <ratbert@faraday-tech.com>
2011-03-27 19:18:37 +02:00

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/*
* Copyright (C) 1998 Dan Malek <dmalek@jlc.net>
* Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
* Copyright (C) 2000-2009 Wolfgang Denk <wd@denx.de>
* Copyright Freescale Semiconductor, Inc. 2004, 2006.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
* Based on the MPC83xx code.
*/
/*
* U-Boot - Startup Code for MPC512x based Embedded Boards
*/
#include <asm-offsets.h>
#include <config.h>
#include <timestamp.h>
#include <version.h>
#define CONFIG_521X 1 /* needed for Linux kernel header files*/
#include <asm/immap_512x.h>
#include "asm-offsets.h"
#include <ppc_asm.tmpl>
#include <ppc_defs.h>
#include <asm/cache.h>
#include <asm/mmu.h>
#include <asm/u-boot.h>
#ifndef CONFIG_IDENT_STRING
#define CONFIG_IDENT_STRING "MPC512X"
#endif
/*
* Floating Point enable, Machine Check and Recoverable Interr.
*/
#undef MSR_KERNEL
#ifdef DEBUG
#define MSR_KERNEL (MSR_FP|MSR_RI)
#else
#define MSR_KERNEL (MSR_FP|MSR_ME|MSR_RI)
#endif
/* Macros for manipulating CSx_START/STOP */
#define START_REG(start) ((start) >> 16)
#define STOP_REG(start, size) (((start) + (size) - 1) >> 16)
/*
* Set up GOT: Global Offset Table
*
* Use r12 to access the GOT
*/
START_GOT
GOT_ENTRY(_GOT2_TABLE_)
GOT_ENTRY(_FIXUP_TABLE_)
GOT_ENTRY(_start)
GOT_ENTRY(_start_of_vectors)
GOT_ENTRY(_end_of_vectors)
GOT_ENTRY(transfer_to_handler)
GOT_ENTRY(__init_end)
GOT_ENTRY(__bss_end__)
GOT_ENTRY(__bss_start)
END_GOT
/*
* Magic number and version string
*/
.long 0x27051956 /* U-Boot Magic Number */
.globl version_string
version_string:
.ascii U_BOOT_VERSION
.ascii " (", U_BOOT_DATE, " - ", U_BOOT_TIME, ")"
.ascii " ", CONFIG_IDENT_STRING, "\0"
/*
* Vector Table
*/
.text
. = EXC_OFF_SYS_RESET
.globl _start
/* Start from here after reset/power on */
_start:
b boot_cold
.globl _start_of_vectors
_start_of_vectors:
/* Machine check */
STD_EXCEPTION(0x200, MachineCheck, MachineCheckException)
/* Data Storage exception. */
STD_EXCEPTION(0x300, DataStorage, UnknownException)
/* Instruction Storage exception. */
STD_EXCEPTION(0x400, InstStorage, UnknownException)
/* External Interrupt exception. */
STD_EXCEPTION(0x500, ExtInterrupt, UnknownException)
/* Alignment exception. */
. = 0x600
Alignment:
EXCEPTION_PROLOG(SRR0, SRR1)
mfspr r4,DAR
stw r4,_DAR(r21)
mfspr r5,DSISR
stw r5,_DSISR(r21)
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_TEMPLATE(Alignment, AlignmentException, MSR_KERNEL, COPY_EE)
/* Program check exception */
. = 0x700
ProgramCheck:
EXCEPTION_PROLOG(SRR0, SRR1)
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_TEMPLATE(ProgramCheck, ProgramCheckException,
MSR_KERNEL, COPY_EE)
/* Floating Point Unit unavailable exception */
STD_EXCEPTION(0x800, FPUnavailable, UnknownException)
/* Decrementer */
STD_EXCEPTION(0x900, Decrementer, timer_interrupt)
/* Critical interrupt */
STD_EXCEPTION(0xa00, Critical, UnknownException)
/* System Call */
STD_EXCEPTION(0xc00, SystemCall, UnknownException)
/* Trace interrupt */
STD_EXCEPTION(0xd00, Trace, UnknownException)
/* Performance Monitor interrupt */
STD_EXCEPTION(0xf00, PerfMon, UnknownException)
/* Intruction Translation Miss */
STD_EXCEPTION(0x1000, InstructionTLBMiss, UnknownException)
/* Data Load Translation Miss */
STD_EXCEPTION(0x1100, DataLoadTLBMiss, UnknownException)
/* Data Store Translation Miss */
STD_EXCEPTION(0x1200, DataStoreTLBMiss, UnknownException)
/* Instruction Address Breakpoint */
STD_EXCEPTION(0x1300, InstructionAddrBreakpoint, DebugException)
/* System Management interrupt */
STD_EXCEPTION(0x1400, SystemMgmtInterrupt, UnknownException)
.globl _end_of_vectors
_end_of_vectors:
. = 0x3000
boot_cold:
/* Save msr contents */
mfmsr r5
/* Set IMMR area to our preferred location */
lis r4, CONFIG_DEFAULT_IMMR@h
lis r3, CONFIG_SYS_IMMR@h
ori r3, r3, CONFIG_SYS_IMMR@l
stw r3, IMMRBAR(r4)
mtspr MBAR, r3 /* IMMRBAR is mirrored into the MBAR SPR (311) */
/* Initialise the machine */
bl cpu_early_init
/*
* Set up Local Access Windows:
*
* 1) Boot/CS0 (boot FLASH)
* 2) On-chip SRAM (initial stack purposes)
*/
/* Boot CS/CS0 window range */
lis r3, CONFIG_SYS_IMMR@h
ori r3, r3, CONFIG_SYS_IMMR@l
lis r4, START_REG(CONFIG_SYS_FLASH_BASE)
ori r4, r4, STOP_REG(CONFIG_SYS_FLASH_BASE, CONFIG_SYS_FLASH_SIZE)
stw r4, LPCS0AW(r3)
/*
* The SRAM window has a fixed size (256K), so only the start address
* is necessary
*/
lis r4, START_REG(CONFIG_SYS_SRAM_BASE) & 0xff00
stw r4, SRAMBAR(r3)
/*
* According to MPC5121e RM, configuring local access windows should
* be followed by a dummy read of the config register that was
* modified last and an isync
*/
lwz r4, SRAMBAR(r3)
isync
/*
* Set configuration of the Boot/CS0, the SRAM window does not have a
* config register so no params can be set for it
*/
lis r3, (CONFIG_SYS_IMMR + LPC_OFFSET)@h
ori r3, r3, (CONFIG_SYS_IMMR + LPC_OFFSET)@l
lis r4, CONFIG_SYS_CS0_CFG@h
ori r4, r4, CONFIG_SYS_CS0_CFG@l
stw r4, CS0_CONFIG(r3)
/* Master enable all CS's */
lis r4, CS_CTRL_ME@h
ori r4, r4, CS_CTRL_ME@l
stw r4, CS_CTRL(r3)
lis r4, (CONFIG_SYS_MONITOR_BASE)@h
ori r4, r4, (CONFIG_SYS_MONITOR_BASE)@l
addi r5, r4, in_flash - _start + EXC_OFF_SYS_RESET
mtlr r5
blr
in_flash:
lis r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET)@h
ori r1, r1, (CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_GBL_DATA_OFFSET)@l
li r0, 0 /* Make room for stack frame header and */
stwu r0, -4(r1) /* clear final stack frame so that */
stwu r0, -4(r1) /* stack backtraces terminate cleanly */
/* let the C-code set up the rest */
/* */
/* Be careful to keep code relocatable & stack humble */
/*------------------------------------------------------*/
GET_GOT /* initialize GOT access */
/* r3: IMMR */
lis r3, CONFIG_SYS_IMMR@h
/* run low-level CPU init code (in Flash) */
bl cpu_init_f
/* run 1st part of board init code (in Flash) */
bl board_init_f
/* NOTREACHED - board_init_f() does not return */
/*
* This code finishes saving the registers to the exception frame
* and jumps to the appropriate handler for the exception.
* Register r21 is pointer into trap frame, r1 has new stack pointer.
*/
.globl transfer_to_handler
transfer_to_handler:
stw r22,_NIP(r21)
lis r22,MSR_POW@h
andc r23,r23,r22
stw r23,_MSR(r21)
SAVE_GPR(7, r21)
SAVE_4GPRS(8, r21)
SAVE_8GPRS(12, r21)
SAVE_8GPRS(24, r21)
mflr r23
andi. r24,r23,0x3f00 /* get vector offset */
stw r24,TRAP(r21)
li r22,0
stw r22,RESULT(r21)
lwz r24,0(r23) /* virtual address of handler */
lwz r23,4(r23) /* where to go when done */
mtspr SRR0,r24
mtspr SRR1,r20
mtlr r23
SYNC
rfi /* jump to handler, enable MMU */
int_return:
mfmsr r28 /* Disable interrupts */
li r4,0
ori r4,r4,MSR_EE
andc r28,r28,r4
SYNC /* Some chip revs need this... */
mtmsr r28
SYNC
lwz r2,_CTR(r1)
lwz r0,_LINK(r1)
mtctr r2
mtlr r0
lwz r2,_XER(r1)
lwz r0,_CCR(r1)
mtspr XER,r2
mtcrf 0xFF,r0
REST_10GPRS(3, r1)
REST_10GPRS(13, r1)
REST_8GPRS(23, r1)
REST_GPR(31, r1)
lwz r2,_NIP(r1) /* Restore environment */
lwz r0,_MSR(r1)
mtspr SRR0,r2
mtspr SRR1,r0
lwz r0,GPR0(r1)
lwz r2,GPR2(r1)
lwz r1,GPR1(r1)
SYNC
rfi
/*
* This code initialises the machine, it expects original MSR contents to be in r5.
*/
cpu_early_init:
/* Initialize machine status; enable machine check interrupt */
/*-----------------------------------------------------------*/
li r3, MSR_KERNEL /* Set ME and RI flags */
rlwimi r3, r5, 0, 25, 25 /* preserve IP bit */
#ifdef DEBUG
rlwimi r3, r5, 0, 21, 22 /* debugger might set SE, BE bits */
#endif
mtmsr r3
SYNC
mtspr SRR1, r3 /* Mirror current MSR state in SRR1 */
lis r3, CONFIG_SYS_IMMR@h
#if defined(CONFIG_WATCHDOG)
/* Initialise the watchdog and reset it */
/*--------------------------------------*/
lis r4, CONFIG_SYS_WATCHDOG_VALUE
ori r4, r4, (SWCRR_SWEN | SWCRR_SWRI | SWCRR_SWPR)
stw r4, SWCRR(r3)
/* reset */
li r4, 0x556C
sth r4, SWSRR@l(r3)
li r4, 0x0
ori r4, r4, 0xAA39
sth r4, SWSRR@l(r3)
#else
/* Disable the watchdog */
/*----------------------*/
lwz r4, SWCRR(r3)
/*
* Check to see if it's enabled for disabling: once disabled by s/w
* it's not possible to re-enable it
*/
andi. r4, r4, 0x4
beq 1f
xor r4, r4, r4
stw r4, SWCRR(r3)
1:
#endif /* CONFIG_WATCHDOG */
/* Initialize the Hardware Implementation-dependent Registers */
/* HID0 also contains cache control */
/*------------------------------------------------------*/
lis r3, CONFIG_SYS_HID0_INIT@h
ori r3, r3, CONFIG_SYS_HID0_INIT@l
SYNC
mtspr HID0, r3
lis r3, CONFIG_SYS_HID0_FINAL@h
ori r3, r3, CONFIG_SYS_HID0_FINAL@l
SYNC
mtspr HID0, r3
lis r3, CONFIG_SYS_HID2@h
ori r3, r3, CONFIG_SYS_HID2@l
SYNC
mtspr HID2, r3
sync
blr
/* Cache functions.
*
* Note: requires that all cache bits in
* HID0 are in the low half word.
*/
.globl icache_enable
icache_enable:
mfspr r3, HID0
ori r3, r3, HID0_ICE
lis r4, 0
ori r4, r4, HID0_ILOCK
andc r3, r3, r4
ori r4, r3, HID0_ICFI
isync
mtspr HID0, r4 /* sets enable and invalidate, clears lock */
isync
mtspr HID0, r3 /* clears invalidate */
blr
.globl icache_disable
icache_disable:
mfspr r3, HID0
lis r4, 0
ori r4, r4, HID0_ICE|HID0_ILOCK
andc r3, r3, r4
ori r4, r3, HID0_ICFI
isync
mtspr HID0, r4 /* sets invalidate, clears enable and lock*/
isync
mtspr HID0, r3 /* clears invalidate */
blr
.globl icache_status
icache_status:
mfspr r3, HID0
rlwinm r3, r3, (31 - HID0_ICE_SHIFT + 1), 31, 31
blr
.globl dcache_enable
dcache_enable:
mfspr r3, HID0
li r5, HID0_DCFI|HID0_DLOCK
andc r3, r3, r5
mtspr HID0, r3 /* no invalidate, unlock */
ori r3, r3, HID0_DCE
ori r5, r3, HID0_DCFI
mtspr HID0, r5 /* enable + invalidate */
mtspr HID0, r3 /* enable */
sync
blr
.globl dcache_disable
dcache_disable:
mfspr r3, HID0
lis r4, 0
ori r4, r4, HID0_DCE|HID0_DLOCK
andc r3, r3, r4
ori r4, r3, HID0_DCI
sync
mtspr HID0, r4 /* sets invalidate, clears enable and lock */
sync
mtspr HID0, r3 /* clears invalidate */
blr
.globl dcache_status
dcache_status:
mfspr r3, HID0
rlwinm r3, r3, (31 - HID0_DCE_SHIFT + 1), 31, 31
blr
.globl get_pvr
get_pvr:
mfspr r3, PVR
blr
/*-------------------------------------------------------------------*/
/*
* void relocate_code (addr_sp, gd, addr_moni)
*
* This "function" does not return, instead it continues in RAM
* after relocating the monitor code.
*
* r3 = dest
* r4 = src
* r5 = length in bytes
* r6 = cachelinesize
*/
.globl relocate_code
relocate_code:
mr r1, r3 /* Set new stack pointer */
mr r9, r4 /* Save copy of Global Data pointer */
mr r10, r5 /* Save copy of Destination Address */
GET_GOT
mr r3, r5 /* Destination Address */
lis r4, CONFIG_SYS_MONITOR_BASE@h /* Source Address */
ori r4, r4, CONFIG_SYS_MONITOR_BASE@l
lwz r5, GOT(__init_end)
sub r5, r5, r4
li r6, CONFIG_SYS_CACHELINE_SIZE /* Cache Line Size */
/*
* Fix GOT pointer:
*
* New GOT-PTR = (old GOT-PTR - CONFIG_SYS_MONITOR_BASE)
* + Destination Address
*
* Offset:
*/
sub r15, r10, r4
/* First our own GOT */
add r12, r12, r15
/* then the one used by the C code */
add r30, r30, r15
/*
* Now relocate code
*/
cmplw cr1,r3,r4
addi r0,r5,3
srwi. r0,r0,2
beq cr1,4f /* In place copy is not necessary */
beq 7f /* Protect against 0 count */
mtctr r0
bge cr1,2f
la r8,-4(r4)
la r7,-4(r3)
/* copy */
1: lwzu r0,4(r8)
stwu r0,4(r7)
bdnz 1b
addi r0,r5,3
srwi. r0,r0,2
mtctr r0
la r8,-4(r4)
la r7,-4(r3)
/* and compare */
20: lwzu r20,4(r8)
lwzu r21,4(r7)
xor. r22, r20, r21
bne 30f
bdnz 20b
b 4f
/* compare failed */
30: li r3, 0
blr
2: slwi r0,r0,2 /* re copy in reverse order ... y do we needed it? */
add r8,r4,r0
add r7,r3,r0
3: lwzu r0,-4(r8)
stwu r0,-4(r7)
bdnz 3b
/*
* Now flush the cache: note that we must start from a cache aligned
* address. Otherwise we might miss one cache line.
*/
4: cmpwi r6,0
add r5,r3,r5
beq 7f /* Always flush prefetch queue in any case */
subi r0,r6,1
andc r3,r3,r0
mr r4,r3
5: dcbst 0,r4
add r4,r4,r6
cmplw r4,r5
blt 5b
sync /* Wait for all dcbst to complete on bus */
mr r4,r3
6: icbi 0,r4
add r4,r4,r6
cmplw r4,r5
blt 6b
7: sync /* Wait for all icbi to complete on bus */
isync
/*
* We are done. Do not return, instead branch to second part of board
* initialization, now running from RAM.
*/
addi r0, r10, in_ram - _start + EXC_OFF_SYS_RESET
mtlr r0
blr
in_ram:
/*
* Relocation Function, r12 point to got2+0x8000
*
* Adjust got2 pointers, no need to check for 0, this code
* already puts a few entries in the table.
*/
li r0,__got2_entries@sectoff@l
la r3,GOT(_GOT2_TABLE_)
lwz r11,GOT(_GOT2_TABLE_)
mtctr r0
sub r11,r3,r11
addi r3,r3,-4
1: lwzu r0,4(r3)
cmpwi r0,0
beq- 2f
add r0,r0,r11
stw r0,0(r3)
2: bdnz 1b
/*
* Now adjust the fixups and the pointers to the fixups
* in case we need to move ourselves again.
*/
li r0,__fixup_entries@sectoff@l
lwz r3,GOT(_FIXUP_TABLE_)
cmpwi r0,0
mtctr r0
addi r3,r3,-4
beq 4f
3: lwzu r4,4(r3)
lwzux r0,r4,r11
cmpwi r0,0
add r0,r0,r11
stw r4,0(r3)
beq- 5f
stw r0,0(r4)
5: bdnz 3b
4:
clear_bss:
/*
* Now clear BSS segment
*/
lwz r3,GOT(__bss_start)
lwz r4,GOT(__bss_end__)
cmplw 0, r3, r4
beq 6f
li r0, 0
5:
stw r0, 0(r3)
addi r3, r3, 4
cmplw 0, r3, r4
bne 5b
6:
mr r3, r9 /* Global Data pointer */
mr r4, r10 /* Destination Address */
bl board_init_r
/*
* Copy exception vector code to low memory
*
* r3: dest_addr
* r7: source address, r8: end address, r9: target address
*/
.globl trap_init
trap_init:
mflr r4 /* save link register */
GET_GOT
lwz r7, GOT(_start)
lwz r8, GOT(_end_of_vectors)
li r9, 0x100 /* reset vector at 0x100 */
cmplw 0, r7, r8
bgelr /* return if r7>=r8 - just in case */
1:
lwz r0, 0(r7)
stw r0, 0(r9)
addi r7, r7, 4
addi r9, r9, 4
cmplw 0, r7, r8
bne 1b
/*
* relocate `hdlr' and `int_return' entries
*/
li r7, .L_MachineCheck - _start + EXC_OFF_SYS_RESET
li r8, Alignment - _start + EXC_OFF_SYS_RESET
2:
bl trap_reloc
addi r7, r7, 0x100 /* next exception vector */
cmplw 0, r7, r8
blt 2b
li r7, .L_Alignment - _start + EXC_OFF_SYS_RESET
bl trap_reloc
li r7, .L_ProgramCheck - _start + EXC_OFF_SYS_RESET
bl trap_reloc
li r7, .L_FPUnavailable - _start + EXC_OFF_SYS_RESET
li r8, SystemCall - _start + EXC_OFF_SYS_RESET
3:
bl trap_reloc
addi r7, r7, 0x100 /* next exception vector */
cmplw 0, r7, r8
blt 3b
li r7, .L_Trace - _start + EXC_OFF_SYS_RESET
li r8, _end_of_vectors - _start + EXC_OFF_SYS_RESET
4:
bl trap_reloc
addi r7, r7, 0x100 /* next exception vector */
cmplw 0, r7, r8
blt 4b
mfmsr r3 /* now that the vectors have */
lis r7, MSR_IP@h /* relocated into low memory */
ori r7, r7, MSR_IP@l /* MSR[IP] can be turned off */
andc r3, r3, r7 /* (if it was on) */
SYNC /* Some chip revs need this... */
mtmsr r3
SYNC
mtlr r4 /* restore link register */
blr
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