powerpc/mpc85xx: Don't relocate exception vectors

Booke does not require exception vectors to be located at address zero.
U-Boot was doing so anyway, simply because that's how it had been done
on other PPC.  The downside of this is that once the OS is loaded to
address zero, the exception vectors have been overwritten -- which
makes it difficult to diagnose a crash that happens after that point.

The IVOR setup and trap entry code is simplified somewhat as a result.

Also, there is no longer a need to align individual exceptions on 0x100
byte boundaries.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
This commit is contained in:
Scott Wood 2015-04-07 20:20:00 -05:00 committed by York Sun
parent 4913229ed6
commit 96d2bb952b
3 changed files with 98 additions and 124 deletions

View file

@ -252,39 +252,36 @@ l2_disabled:
lis r1,CONFIG_SYS_MONITOR_BASE@h
mtspr IVPR,r1
lis r3,(CONFIG_SYS_MONITOR_BASE & 0xffff)@h
ori r3,r3,(CONFIG_SYS_MONITOR_BASE & 0xffff)@l
addi r4,r3,CriticalInput - _start + _START_OFFSET
li r4,CriticalInput@l
mtspr IVOR0,r4 /* 0: Critical input */
addi r4,r3,MachineCheck - _start + _START_OFFSET
li r4,MachineCheck@l
mtspr IVOR1,r4 /* 1: Machine check */
addi r4,r3,DataStorage - _start + _START_OFFSET
li r4,DataStorage@l
mtspr IVOR2,r4 /* 2: Data storage */
addi r4,r3,InstStorage - _start + _START_OFFSET
li r4,InstStorage@l
mtspr IVOR3,r4 /* 3: Instruction storage */
addi r4,r3,ExtInterrupt - _start + _START_OFFSET
li r4,ExtInterrupt@l
mtspr IVOR4,r4 /* 4: External interrupt */
addi r4,r3,Alignment - _start + _START_OFFSET
li r4,Alignment@l
mtspr IVOR5,r4 /* 5: Alignment */
addi r4,r3,ProgramCheck - _start + _START_OFFSET
li r4,ProgramCheck@l
mtspr IVOR6,r4 /* 6: Program check */
addi r4,r3,FPUnavailable - _start + _START_OFFSET
li r4,FPUnavailable@l
mtspr IVOR7,r4 /* 7: floating point unavailable */
addi r4,r3,SystemCall - _start + _START_OFFSET
li r4,SystemCall@l
mtspr IVOR8,r4 /* 8: System call */
/* 9: Auxiliary processor unavailable(unsupported) */
addi r4,r3,Decrementer - _start + _START_OFFSET
li r4,Decrementer@l
mtspr IVOR10,r4 /* 10: Decrementer */
addi r4,r3,IntervalTimer - _start + _START_OFFSET
li r4,IntervalTimer@l
mtspr IVOR11,r4 /* 11: Interval timer */
addi r4,r3,WatchdogTimer - _start + _START_OFFSET
li r4,WatchdogTimer@l
mtspr IVOR12,r4 /* 12: Watchdog timer */
addi r4,r3,DataTLBError - _start + _START_OFFSET
li r4,DataTLBError@l
mtspr IVOR13,r4 /* 13: Data TLB error */
addi r4,r3,InstructionTLBError - _start + _START_OFFSET
li r4,InstructionTLBError@l
mtspr IVOR14,r4 /* 14: Instruction TLB error */
addi r4,r3,DebugBreakpoint - _start + _START_OFFSET
li r4,DebugBreakpoint@l
mtspr IVOR15,r4 /* 15: Debug */
#endif
@ -1121,7 +1118,7 @@ switch_as:
/*--------------------------------------------------------------*/
lis r3,CONFIG_SYS_MONITOR_BASE@h
ori r3,r3,CONFIG_SYS_MONITOR_BASE@l
addi r3,r3,_start_cont - _start + _START_OFFSET
addi r3,r3,_start_cont - _start
mtlr r3
blr
#endif
@ -1165,7 +1162,6 @@ _start_cont:
/* NOTREACHED - board_init_f() does not return */
#ifndef MINIMAL_SPL
. = EXC_OFF_SYS_RESET
.globl _start_of_vectors
_start_of_vectors:
@ -1185,7 +1181,6 @@ _start_of_vectors:
STD_EXCEPTION(0x0500, ExtInterrupt, ExtIntException)
/* Alignment exception. */
. = 0x0600
Alignment:
EXCEPTION_PROLOG(SRR0, SRR1)
mfspr r4,DAR
@ -1193,21 +1188,20 @@ Alignment:
mfspr r5,DSISR
stw r5,_DSISR(r21)
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_TEMPLATE(Alignment, AlignmentException, MSR_KERNEL, COPY_EE)
EXC_XFER_TEMPLATE(0x600, Alignment, AlignmentException,
MSR_KERNEL, COPY_EE)
/* Program check exception */
. = 0x0700
ProgramCheck:
EXCEPTION_PROLOG(SRR0, SRR1)
addi r3,r1,STACK_FRAME_OVERHEAD
EXC_XFER_TEMPLATE(ProgramCheck, ProgramCheckException,
EXC_XFER_TEMPLATE(0x700, ProgramCheck, ProgramCheckException,
MSR_KERNEL, COPY_EE)
/* No FPU on MPC85xx. This exception is not supposed to happen.
*/
STD_EXCEPTION(0x0800, FPUnavailable, UnknownException)
. = 0x0900
/*
* r0 - SYSCALL number
* r3-... arguments
@ -1293,32 +1287,22 @@ _end_of_vectors:
* 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.
* r23 is the address of the handler.
*/
.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)
mtspr SPRG2,r22 /* r1 is now kernel sp */
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 */
mtctr r23 /* virtual address of handler */
mtmsr r20
bctrl
int_return:
mfmsr r28 /* Disable interrupts */
@ -1728,7 +1712,7 @@ relocate_code:
* initialization, now running from RAM.
*/
addi r0,r10,in_ram - _start + _START_OFFSET
addi r0,r10,in_ram - _start
/*
* As IVPR is going to point RAM address,
@ -1816,89 +1800,41 @@ clear_bss:
*/
.globl trap_init
trap_init:
mflr r4 /* save link register */
GET_GOT
lwz r7,GOT(_start_of_vectors)
lwz r8,GOT(_end_of_vectors)
/* Update IVORs as per relocation */
mtspr IVPR,r3
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_CriticalInput - _start + _START_OFFSET
bl trap_reloc
li r7,.L_MachineCheck - _start + _START_OFFSET
bl trap_reloc
li r7,.L_DataStorage - _start + _START_OFFSET
bl trap_reloc
li r7,.L_InstStorage - _start + _START_OFFSET
bl trap_reloc
li r7,.L_ExtInterrupt - _start + _START_OFFSET
bl trap_reloc
li r7,.L_Alignment - _start + _START_OFFSET
bl trap_reloc
li r7,.L_ProgramCheck - _start + _START_OFFSET
bl trap_reloc
li r7,.L_FPUnavailable - _start + _START_OFFSET
bl trap_reloc
li r7,.L_Decrementer - _start + _START_OFFSET
bl trap_reloc
li r7,.L_IntervalTimer - _start + _START_OFFSET
li r8,_end_of_vectors - _start + _START_OFFSET
2:
bl trap_reloc
addi r7,r7,0x100 /* next exception vector */
cmplw 0,r7,r8
blt 2b
/* Update IVORs as per relocated vector table address */
li r7,0x0100
mtspr IVOR0,r7 /* 0: Critical input */
li r7,0x0200
mtspr IVOR1,r7 /* 1: Machine check */
li r7,0x0300
mtspr IVOR2,r7 /* 2: Data storage */
li r7,0x0400
mtspr IVOR3,r7 /* 3: Instruction storage */
li r7,0x0500
mtspr IVOR4,r7 /* 4: External interrupt */
li r7,0x0600
mtspr IVOR5,r7 /* 5: Alignment */
li r7,0x0700
mtspr IVOR6,r7 /* 6: Program check */
li r7,0x0800
mtspr IVOR7,r7 /* 7: floating point unavailable */
li r7,0x0900
mtspr IVOR8,r7 /* 8: System call */
li r4,CriticalInput@l
mtspr IVOR0,r4 /* 0: Critical input */
li r4,MachineCheck@l
mtspr IVOR1,r4 /* 1: Machine check */
li r4,DataStorage@l
mtspr IVOR2,r4 /* 2: Data storage */
li r4,InstStorage@l
mtspr IVOR3,r4 /* 3: Instruction storage */
li r4,ExtInterrupt@l
mtspr IVOR4,r4 /* 4: External interrupt */
li r4,Alignment@l
mtspr IVOR5,r4 /* 5: Alignment */
li r4,ProgramCheck@l
mtspr IVOR6,r4 /* 6: Program check */
li r4,FPUnavailable@l
mtspr IVOR7,r4 /* 7: floating point unavailable */
li r4,SystemCall@l
mtspr IVOR8,r4 /* 8: System call */
/* 9: Auxiliary processor unavailable(unsupported) */
li r7,0x0a00
mtspr IVOR10,r7 /* 10: Decrementer */
li r7,0x0b00
mtspr IVOR11,r7 /* 11: Interval timer */
li r7,0x0c00
mtspr IVOR12,r7 /* 12: Watchdog timer */
li r7,0x0d00
mtspr IVOR13,r7 /* 13: Data TLB error */
li r7,0x0e00
mtspr IVOR14,r7 /* 14: Instruction TLB error */
li r7,0x0f00
mtspr IVOR15,r7 /* 15: Debug */
li r4,Decrementer@l
mtspr IVOR10,r4 /* 10: Decrementer */
li r4,IntervalTimer@l
mtspr IVOR11,r4 /* 11: Interval timer */
li r4,WatchdogTimer@l
mtspr IVOR12,r4 /* 12: Watchdog timer */
li r4,DataTLBError@l
mtspr IVOR13,r4 /* 13: Data TLB error */
li r4,InstructionTLBError@l
mtspr IVOR14,r4 /* 14: Instruction TLB error */
li r4,DebugBreakpoint@l
mtspr IVOR15,r4 /* 15: Debug */
lis r7,0x0
mtspr IVPR,r7
mtlr r4 /* restore link register */
blr
.globl unlock_ram_in_cache

View file

@ -6,10 +6,6 @@
#ifndef __MPC85xx_H__
#define __MPC85xx_H__
/* define for common ppc_asm.tmpl */
#define EXC_OFF_SYS_RESET 0x100 /* System reset */
#define _START_OFFSET 0
#if defined(CONFIG_E500)
#include <e500.h>
#endif

View file

@ -12,6 +12,8 @@
#ifndef __PPC_ASM_TMPL__
#define __PPC_ASM_TMPL__
#include <config.h>
/***************************************************************************
*
* These definitions simplify the ugly declarations necessary for GOT
@ -243,6 +245,45 @@
*/
#define COPY_EE(d, s) rlwimi d,s,0,16,16
#define NOCOPY(d, s)
#ifdef CONFIG_E500
#define EXC_XFER_TEMPLATE(n, label, hdlr, msr, copyee) \
stw r22,_NIP(r21); \
stw r23,_MSR(r21); \
li r23,n; \
stw r23,TRAP(r21); \
li r20,msr; \
copyee(r20,r23); \
rlwimi r20,r23,0,25,25; \
mtmsr r20; \
bl 1f; \
1: mflr r23; \
addis r23,r23,(hdlr - 1b)@ha; \
addi r23,r23,(hdlr - 1b)@l; \
b transfer_to_handler
#define STD_EXCEPTION(n, label, hdlr) \
label: \
EXCEPTION_PROLOG(SRR0, SRR1); \
addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_TEMPLATE(n, label, hdlr, MSR_KERNEL, NOCOPY) \
#define CRIT_EXCEPTION(n, label, hdlr) \
label: \
EXCEPTION_PROLOG(CSRR0, CSRR1); \
addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_TEMPLATE(n, label, hdlr, \
MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE), NOCOPY) \
#define MCK_EXCEPTION(n, label, hdlr) \
label: \
EXCEPTION_PROLOG(MCSRR0, MCSRR1); \
addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_TEMPLATE(n, label, hdlr, \
MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE), NOCOPY) \
#else /* !E500 */
#define EXC_XFER_TEMPLATE(label, hdlr, msr, copyee) \
bl 1f; \
1: mflr r20; \
@ -280,4 +321,5 @@ label: \
EXC_XFER_TEMPLATE(label, hdlr, \
MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE), NOCOPY) \
#endif /* !E500 */
#endif /* __PPC_ASM_TMPL__ */