u-boot/arch/powerpc/cpu/mpc824x/start.S
Stefan Roese a47a12becf Move arch/ppc to arch/powerpc
As discussed on the list, move "arch/ppc" to "arch/powerpc" to
better match the Linux directory structure.

Please note that this patch also changes the "ppc" target in
MAKEALL to "powerpc" to match this new infrastructure. But "ppc"
is kept as an alias for now, to not break compatibility with
scripts using this name.

Signed-off-by: Stefan Roese <sr@denx.de>
Acked-by: Wolfgang Denk <wd@denx.de>
Acked-by: Detlev Zundel <dzu@denx.de>
Acked-by: Kim Phillips <kim.phillips@freescale.com>
Cc: Peter Tyser <ptyser@xes-inc.com>
Cc: Anatolij Gustschin <agust@denx.de>
2010-04-21 23:42:38 +02:00

766 lines
17 KiB
ArmAsm

/*
* Copyright (C) 1998 Dan Malek <dmalek@jlc.net>
* Copyright (C) 1999 Magnus Damm <kieraypc01.p.y.kie.era.ericsson.se>
* Copyright (C) 2000,2001,2002 Wolfgang Denk <wd@denx.de>
*
* 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
*/
/* U-Boot - Startup Code for PowerPC based Embedded Boards
*
*
* The processor starts at 0x00000100 and the code is executed
* from flash. The code is organized to be at an other address
* in memory, but as long we don't jump around before relocating.
* board_init lies at a quite high address and when the cpu has
* jumped there, everything is ok.
* This works because the cpu gives the FLASH (CS0) the whole
* address space at startup, and board_init lies as a echo of
* the flash somewhere up there in the memorymap.
*
* board_init will change CS0 to be positioned at the correct
* address and (s)dram will be positioned at address 0
*/
#include <config.h>
#include <mpc824x.h>
#include <timestamp.h>
#include <version.h>
#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>
#ifndef CONFIG_IDENT_STRING
#define CONFIG_IDENT_STRING ""
#endif
/* We don't want the MMU yet.
*/
#undef MSR_KERNEL
/* FP, Machine Check and Recoverable Interr. */
#define MSR_KERNEL ( MSR_FP | MSR_ME | MSR_RI )
/*
* 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(_end)
GOT_ENTRY(__bss_start)
#if defined(CONFIG_FADS)
GOT_ENTRY(environment)
#endif
END_GOT
/*
* r3 - 1st arg to board_init(): IMMP pointer
* r4 - 2nd arg to board_init(): boot flag
*/
.text
.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"
. = EXC_OFF_SYS_RESET
.globl _start
_start:
li r21, BOOTFLAG_COLD /* Normal Power-On: Boot from FLASH */
b boot_cold
. = EXC_OFF_SYS_RESET + 0x10
.globl _start_warm
_start_warm:
li r21, BOOTFLAG_WARM /* Software reboot */
b boot_warm
boot_cold:
boot_warm:
/* Initialize machine status; enable machine check interrupt */
/*----------------------------------------------------------------------*/
li r3, MSR_KERNEL /* Set FP, ME, RI flags */
mtmsr r3
mtspr SRR1, r3 /* Make SRR1 match MSR */
addis r0,0,0x0000 /* lets make sure that r0 is really 0 */
mtspr HID0, r0 /* disable I and D caches */
mfspr r3, ICR /* clear Interrupt Cause Register */
mfmsr r3 /* turn off address translation */
addis r4,0,0xffff
ori r4,r4,0xffcf
and r3,r3,r4
mtmsr r3
isync
sync /* the MMU should be off... */
in_flash:
#if defined(CONFIG_BMW)
bl early_init_f /* Must be ASM: no stack yet! */
#endif
/*
* Setup BATs - cannot be done in C since we don't have a stack yet
*/
bl setup_bats
/* Enable MMU.
*/
mfmsr r3
ori r3, r3, (MSR_IR | MSR_DR)
mtmsr r3
#if !defined(CONFIG_BMW)
/* Enable and invalidate data cache.
*/
mfspr r3, HID0
mr r2, r3
ori r3, r3, HID0_DCE | HID0_DCI
ori r2, r2, HID0_DCE
sync
mtspr HID0, r3
mtspr HID0, r2
sync
/* Allocate Initial RAM in data cache.
*/
lis r3, CONFIG_SYS_INIT_RAM_ADDR@h
ori r3, r3, CONFIG_SYS_INIT_RAM_ADDR@l
li r2, 128
mtctr r2
1:
dcbz r0, r3
addi r3, r3, 32
bdnz 1b
/* Lock way0 in data cache.
*/
mfspr r3, 1011
lis r2, 0xffff
ori r2, r2, 0xff1f
and r3, r3, r2
ori r3, r3, 0x0080
sync
mtspr 1011, r3
#endif /* !CONFIG_BMW */
/*
* Thisk the stack pointer *somewhere* sensible. Doesnt
* matter much where as we'll move it when we relocate
*/
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 ! */
/*----------------------------------------------------------------------*/
GET_GOT /* initialize GOT access */
/* r3: IMMR */
bl cpu_init_f /* run low-level CPU init code (from Flash) */
mr r3, r21
/* r3: BOOTFLAG */
bl board_init_f /* run 1st part of board init code (from Flash) */
.globl _start_of_vectors
_start_of_vectors:
/* Machine check */
STD_EXCEPTION(EXC_OFF_MACH_CHCK, MachineCheck, MachineCheckException)
/* Data Storage exception. "Never" generated on the 860. */
STD_EXCEPTION(EXC_OFF_DATA_STOR, DataStorage, UnknownException)
/* Instruction Storage exception. "Never" generated on the 860. */
STD_EXCEPTION(EXC_OFF_INS_STOR, InstStorage, UnknownException)
/* External Interrupt exception. */
STD_EXCEPTION(EXC_OFF_EXTERNAL, ExtInterrupt, external_interrupt)
/* Alignment exception. */
. = EXC_OFF_ALIGN
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 */
. = EXC_OFF_PROGRAM
ProgramCheck:
EXCEPTION_PROLOG(SRR0, SRR1)
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_TEMPLATE(ProgramCheck, ProgramCheckException,
MSR_KERNEL, COPY_EE)
/* No FPU on MPC8xx. This exception is not supposed to happen.
*/
STD_EXCEPTION(EXC_OFF_FPUNAVAIL, FPUnavailable, UnknownException)
/* I guess we could implement decrementer, and may have
* to someday for timekeeping.
*/
STD_EXCEPTION(EXC_OFF_DECR, Decrementer, timer_interrupt)
STD_EXCEPTION(0xa00, Trap_0a, UnknownException)
STD_EXCEPTION(0xb00, Trap_0b, UnknownException)
STD_EXCEPTION(0xc00, SystemCall, UnknownException)
STD_EXCEPTION(EXC_OFF_TRACE, SingleStep, UnknownException)
STD_EXCEPTION(EXC_OFF_FPUNASSIST, Trap_0e, UnknownException)
STD_EXCEPTION(EXC_OFF_PMI, Trap_0f, UnknownException)
STD_EXCEPTION(EXC_OFF_ITME, InstructionTransMiss, UnknownException)
STD_EXCEPTION(EXC_OFF_DLTME, DataLoadTransMiss, UnknownException)
STD_EXCEPTION(EXC_OFF_DSTME, DataStoreTransMiss, UnknownException)
STD_EXCEPTION(EXC_OFF_IABE, InstructionBreakpoint, DebugException)
STD_EXCEPTION(EXC_OFF_SMIE, SysManageInt, UnknownException)
STD_EXCEPTION(0x1500, Reserved5, UnknownException)
STD_EXCEPTION(0x1600, Reserved6, UnknownException)
STD_EXCEPTION(0x1700, Reserved7, UnknownException)
STD_EXCEPTION(0x1800, Reserved8, UnknownException)
STD_EXCEPTION(0x1900, Reserved9, UnknownException)
STD_EXCEPTION(0x1a00, ReservedA, UnknownException)
STD_EXCEPTION(0x1b00, ReservedB, UnknownException)
STD_EXCEPTION(0x1c00, ReservedC, UnknownException)
STD_EXCEPTION(0x1d00, ReservedD, UnknownException)
STD_EXCEPTION(0x1e00, ReservedE, UnknownException)
STD_EXCEPTION(0x1f00, ReservedF, UnknownException)
STD_EXCEPTION(EXC_OFF_RMTE, RunModeTrace, UnknownException)
.globl _end_of_vectors
_end_of_vectors:
. = 0x3000
/*
* 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)
#if 0
andi. r23,r23,MSR_PR
mfspr r23,SPRG3 /* if from user, fix up tss.regs */
beq 2f
addi r24,r1,STACK_FRAME_OVERHEAD
stw r24,PT_REGS(r23)
2: addi r2,r23,-TSS /* set r2 to current */
tovirt(r2,r2,r23)
#endif
mflr r23
andi. r24,r23,0x3f00 /* get vector offset */
stw r24,TRAP(r21)
li r22,0
stw r22,RESULT(r21)
mtspr SPRG2,r22 /* r1 is now kernel sp */
#if 0
addi r24,r2,TASK_STRUCT_SIZE /* check for kernel stack overflow */
cmplw 0,r1,r2
cmplw 1,r1,r24
crand 1,1,4
bgt stack_ovf /* if r2 < r1 < r2+TASK_STRUCT_SIZE */
#endif
lwz r24,0(r23) /* virtual address of handler */
lwz r23,4(r23) /* where to go when done */
mtspr SRR0,r24
ori r20,r20,0x30 /* enable IR, DR */
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
/* Cache functions.
*/
.globl icache_enable
icache_enable:
mfspr r5,HID0 /* turn on the I cache. */
ori r5,r5,0x8800 /* Instruction cache only! */
addis r6,0,0xFFFF
ori r6,r6,0xF7FF
and r6,r5,r6 /* clear the invalidate bit */
sync
mtspr HID0,r5
mtspr HID0,r6
isync
sync
blr
.globl icache_disable
icache_disable:
mfspr r5,HID0
addis r6,0,0xFFFF
ori r6,r6,0x7FFF
and r5,r5,r6
sync
mtspr HID0,r5
isync
sync
blr
.globl icache_status
icache_status:
mfspr r3, HID0
srwi r3, r3, 15 /* >>15 & 1=> select bit 16 */
andi. r3, r3, 1
blr
.globl dcache_enable
dcache_enable:
mfspr r5,HID0 /* turn on the D cache. */
ori r5,r5,0x4400 /* Data cache only! */
mfspr r4, PVR /* read PVR */
srawi r3, r4, 16 /* shift off the least 16 bits */
cmpi 0, 0, r3, 0xC /* Check for Max pvr */
bne NotMax
ori r5,r5,0x0040 /* setting the DCFA bit, for Max rev 1 errata */
NotMax:
addis r6,0,0xFFFF
ori r6,r6,0xFBFF
and r6,r5,r6 /* clear the invalidate bit */
sync
mtspr HID0,r5
mtspr HID0,r6
isync
sync
blr
.globl dcache_disable
dcache_disable:
mfspr r5,HID0
addis r6,0,0xFFFF
ori r6,r6,0xBFFF
and r5,r5,r6
sync
mtspr HID0,r5
isync
sync
blr
.globl dcache_status
dcache_status:
mfspr r3, HID0
srwi r3, r3, 14 /* >>14 & 1=> select bit 17 */
andi. r3, r3, 1
blr
.globl dc_read
dc_read:
/*TODO : who uses this, what should it do?
*/
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 */
#ifdef CONFIG_SYS_RAMBOOT
lis r4, CONFIG_SYS_SDRAM_BASE@h /* Source Address */
ori r4, r4, CONFIG_SYS_SDRAM_BASE@l
#else
lis r4, CONFIG_SYS_MONITOR_BASE@h /* Source Address */
ori r4, r4, CONFIG_SYS_MONITOR_BASE@l
#endif
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
/* the 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)
1: lwzu r0,4(r8)
stwu r0,4(r7)
bdnz 1b
b 4f
2: slwi r0,r0,2
add r8,r4,r0
add r7,r3,r0
3: lwzu r0,-4(r8)
stwu r0,-4(r7)
bdnz 3b
4:
#if !defined(CONFIG_BMW)
/* Unlock the data cache and invalidate locked area */
xor r0, r0, r0
mtspr 1011, r0
lis r4, CONFIG_SYS_INIT_RAM_ADDR@h
ori r4, r4, CONFIG_SYS_INIT_RAM_ADDR@l
li r0, 128
mtctr r0
41:
dcbi r0, r4
addi r4, r4, 32
bdnz 41b
#endif
/*
* Now flush the cache: note that we must start from a cache aligned
* address. Otherwise we might miss one cache line.
*/
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
add r0,r0,r11
stw r10,0(r3)
stw r0,0(r4)
bdnz 3b
4:
clear_bss:
/*
* Now clear BSS segment
*/
lwz r3,GOT(__bss_start)
lwz r4,GOT(_end)
cmplw 0, r3, r4
beq 6f
li r0, 0
5:
stw r0, 0(r3)
addi r3, r3, 4
cmplw 0, r3, r4
blt 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 always 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_SingleStep - _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
mtlr r4 /* restore link register */
blr
/* Setup the BAT registers.
*/
setup_bats:
lis r4, CONFIG_SYS_IBAT0L@h
ori r4, r4, CONFIG_SYS_IBAT0L@l
lis r3, CONFIG_SYS_IBAT0U@h
ori r3, r3, CONFIG_SYS_IBAT0U@l
mtspr IBAT0L, r4
mtspr IBAT0U, r3
isync
lis r4, CONFIG_SYS_DBAT0L@h
ori r4, r4, CONFIG_SYS_DBAT0L@l
lis r3, CONFIG_SYS_DBAT0U@h
ori r3, r3, CONFIG_SYS_DBAT0U@l
mtspr DBAT0L, r4
mtspr DBAT0U, r3
isync
lis r4, CONFIG_SYS_IBAT1L@h
ori r4, r4, CONFIG_SYS_IBAT1L@l
lis r3, CONFIG_SYS_IBAT1U@h
ori r3, r3, CONFIG_SYS_IBAT1U@l
mtspr IBAT1L, r4
mtspr IBAT1U, r3
isync
lis r4, CONFIG_SYS_DBAT1L@h
ori r4, r4, CONFIG_SYS_DBAT1L@l
lis r3, CONFIG_SYS_DBAT1U@h
ori r3, r3, CONFIG_SYS_DBAT1U@l
mtspr DBAT1L, r4
mtspr DBAT1U, r3
isync
lis r4, CONFIG_SYS_IBAT2L@h
ori r4, r4, CONFIG_SYS_IBAT2L@l
lis r3, CONFIG_SYS_IBAT2U@h
ori r3, r3, CONFIG_SYS_IBAT2U@l
mtspr IBAT2L, r4
mtspr IBAT2U, r3
isync
lis r4, CONFIG_SYS_DBAT2L@h
ori r4, r4, CONFIG_SYS_DBAT2L@l
lis r3, CONFIG_SYS_DBAT2U@h
ori r3, r3, CONFIG_SYS_DBAT2U@l
mtspr DBAT2L, r4
mtspr DBAT2U, r3
isync
lis r4, CONFIG_SYS_IBAT3L@h
ori r4, r4, CONFIG_SYS_IBAT3L@l
lis r3, CONFIG_SYS_IBAT3U@h
ori r3, r3, CONFIG_SYS_IBAT3U@l
mtspr IBAT3L, r4
mtspr IBAT3U, r3
isync
lis r4, CONFIG_SYS_DBAT3L@h
ori r4, r4, CONFIG_SYS_DBAT3L@l
lis r3, CONFIG_SYS_DBAT3U@h
ori r3, r3, CONFIG_SYS_DBAT3U@l
mtspr DBAT3L, r4
mtspr DBAT3U, r3
isync
/* Invalidate TLBs.
* -> for (val = 0; val < 0x20000; val+=0x1000)
* -> tlbie(val);
*/
lis r3, 0
lis r5, 2
1:
tlbie r3
addi r3, r3, 0x1000
cmp 0, 0, r3, r5
blt 1b
blr