/*
* <vectors.S>
*
* Second stage boot-loader and exception vectors for Open Hack'Ware.
*
* Copyright (C) 2004-2005 Jocelyn Mayer (l_indien@magic.fr)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License V2
* as published by the Free Software Foundation
*
* 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
*/
#define ASSEMBLY_CODE
#include "bios.h"
.section .text
.align 2
.globl _start
_start:
/* Entry point */
li r0, 0 ;
_turn_off_mmu:
/* Be sure MMU is off and we are in 32 bits mode (for PPC64) */
lis r11, _hw_init@h ;
ori r11, r11, _hw_init@l ;
mtspr 26, r11 ;
mtspr 27, r0 ;
rfi ;
_hw_init:
/* May need more hw init here */
_load_bios:
/* Load the full BIOS into RAM */
lis r12, bios_base@h ;
ori r12, r12, bios_base@l ;
lmw r29, 0(r12) ;
/* Set up the C stack */
addis r1, r29, 0x0040 ;
clrrwi r1, r1, 19 ;
stw r1, -16(r1) ;
stwu r0, -4(r1) ;
stwu r0, -4(r1) ;
stwu r0, -4(r1) ;
stwu r0, -4(r1) ;
/* Skip frame pointer */
stwu r0, -8(r1) ;
stwu r0, -4(r1) ;
stwu r0, -4(r1) ;
/* Start copying */
mtctr r30 ;
subi r12, r3, 4 ;
subi r13, r29, 4 ;
_bios_copy_loop:
lwzu r14, 4(r12) ;
stwu r14, 4(r13) ;
bdnz _bios_copy_loop ;
/* Synchronize the whole execution context */
/* Also enable FPU */
ori r0, r0, (1 << 13) ;
mtspr 26, r29 ;
mtspr 27, r0 ;
rfi ;
/* If we ever return, stop */
bl bug ;
.org 0x0080
.section .text
.align 2
bug:
/* Dump the exception and its context */
mflr r3 ;
mfspr r4, SRR0 ;
mfspr r5, SRR1 ;
mfspr r6, DAR ;
mfspr r7, DSISR ;
/* Turn MMU off */
lis r0, _bug_no_mmu@h ;
ori r0, r0, _bug_no_mmu@l ;
mtspr 26, r0 ;
li r0, 0 ;
mtspr 27, r0 ;
rfi ;
_bug_no_mmu:
bl dump_exception ;
_forever:
/* Loop forever */
b _forever ;
skip_exception:
/* Skip external interrupts and decrementer exception */
/* BEWARE: be sure not to modify any register */
stw r11, save_area@l(0) ;
mfspr r11, 27 ;
clrlwi r11, r11, 16 ;
mtspr 27, r11 ;
lwz r11, save_area@l(0) ;
rfi ;
#define EXCP_BUG(entry) \
.org 0x##entry ; \
.section .text ; \
.align 2 ; \
excp_##entry: ; \
bl bug
#define EXCP_SKIP(entry) \
.org 0x##entry ; \
.section .text ; \
.align 2 ; \
excp_##entry##: ; \
b skip_exception
/* Exception vectors */
/* Reset exception */
.org 0x0100
excp_0100:
ba 0xfffffffc
/* Machine check exception */
EXCP_BUG(0200) ;
/* DSI exception */
EXCP_BUG(0300) ;
/* ISI exception */
EXCP_BUG(0400) ;
/* External interrupt: skip it */
EXCP_SKIP(0500) ;
/* Alignment exception */
EXCP_BUG(0600) ;
/* Program exception */
EXCP_BUG(0700) ;
/* No floating point exception */
EXCP_BUG(0800) ;
/* Decrementer exception: skip it */
EXCP_SKIP(0900) ;
/* Reserved A exception */
EXCP_BUG(0A00) ;
/* Reserved B exception */
EXCP_BUG(0B00) ;
/* System call exception */
EXCP_BUG(0C00) ;
/* Trace exception */
EXCP_BUG(0D00) ;
/* Floating point assist exception */
EXCP_BUG(0E00) ;
/* Performance monitor exception */
EXCP_BUG(0F00) ;
/* Instruction TLB miss exception */
EXCP_BUG(1000) ;
/* Data TLB miss for store exception */
EXCP_BUG(1100) ;
/* Data TLB miss for load exception */
EXCP_BUG(1200) ;
/* Instruction address breakpoint exception */
EXCP_BUG(1300) ;
/* System management interrupt exception */
EXCP_BUG(1400) ;
/* Thermal management exception */
EXCP_BUG(1500) ;
/* Unknown exceptions */
EXCP_BUG(1600) ;
EXCP_BUG(1700) ;
EXCP_BUG(1800) ;
EXCP_BUG(1900) ;
EXCP_BUG(1A00) ;
EXCP_BUG(1B00) ;
EXCP_BUG(1C00) ;
EXCP_BUG(1D00) ;
EXCP_BUG(1E00) ;
EXCP_BUG(1F00) ;
/* End of exception vectors list */
.org 0x2000
.section .text
.align 2
helpers_start:
outb:
/* void outb (uint32_t port, uint32_t data);
* Writes a single character on an IO port.
* Used for serial console.
*/
stb r4, 0(r3) ;
eieio ;
blr ;
outstr:
/* void outstr (uint32_t port, const unsigned char *str);
* Writes a string on an IO port.
*/
mflr r20 ;
subi r11, r4, 1 ;
_outstr_next:
lbzu r4, 1(r11) ;
cmpi 0, r4, 0 ;
beq _outstr_done ;
bl outb ;
b _outstr_next ;
_outstr_done:
mtlr r20 ;
blr ;
outdigit:
/* void outdigit (uint32_t port, uint32_t digit);
* Dumps a single digit on serial port.
*/
mflr r20 ;
addi r4, r4, '0' ;
bl outb ;
mtlr r20 ;
blr ;
outhex:
/* void outhex (uint32_t port, uint32_t value);
* Dumps a 32 bits hex number on serial port
*/
mflr r21
li r11, 8 ;
mtctr r11 ;
mr r11, r4 ;
_outhex_next:
rlwinm r11, r11, 4, 0, 31 ;
clrlwi r4, r11, 28 ;
cmpi 0, r4, 9 ;
bgt _outhex_xdigit ;
bl outdigit ;
bdnz _outhex_next ;
b _outhex_done ;
_outhex_xdigit:
addi r4, r4, 'a' - 10 ;
bl outb ;
bdnz _outhex_next ;
_outhex_done:
mtlr r21 ;
blr ;
/* void dump_exception (uint32_t lr, uint32_t srr0, uint32_t srr1,
* uint32_t dar, uint32_t dsisr);
* Dump a message when catching an exception
*/
dump_exception:
/* Save call parameters */
mflr r19 ;
mr r22, r3 ;
mr r23, r4 ;
mr r24, r5 ;
mr r25, r6 ;
mr r26, r7 ;
lis r11, registers_area@h ;
ori r11, r11, registers_area@l ;
lmw r27, 0(r11) ;
/* Now, serial IO port is in r27,
* message table start is in r28,
* first exception message offset is in r29,
* and last known exception number is in r30
*/
/* Print error prompt message */
mr r3, r27 ;
lwzu r4, 4(r28) ;
bl outstr ;
/* Find message corresponding to the caught exception */
srwi r12, r22, 8 ;
cmp 0, r12, r30 ;
ble _dump_excp_msg ;
subi r12, r30, 1 ;
_dump_excp_msg:
rlwinm r12, r12, 2, 0, 31 ;
/* Dump execption message */
mr r3, r27 ;
lwzx r4, r12, r29 ;
bl outstr ;
/* Complete exception message */
mr r3, r27 ;
lwzu r4, 4(r28) ;
bl outstr ;
/* Dump nip */
mr r3, r27 ;
lwzu r4, 4(r28) ;
bl outstr ;
mr r3, r27 ;
mr r4, r23 ;
bl outhex ;
/* dump msr */
mr r3, r27 ;
lwzu r4, 4(r28) ;
bl outstr ;
mr r3, r27 ;
mr r4, r24 ;
bl outhex ;
/* dump dar */
mr r3, r27 ;
lwzu r4, 4(r28) ;
bl outstr ;
mr r3, r27 ;
mr r4, r25 ;
bl outhex ;
/* dump dsisr */
mr r3, r27 ;
lwzu r4, 4(r28) ;
bl outstr ;
mr r3, r27 ;
mr r4, r26 ;
bl outhex ;
/* All done, dump last message and return */
mr r3, r27 ;
lwzu r4, 4(r28) ;
bl outstr ;
mtlr r19 ;
blr ;
.section .rodata
.align 2
_BUG_message_0:
.string "ERROR: BUG caught...\n"
_BUG_message_1:
.string " exception"
_BUG_message_2:
.string "\nnip=0x"
_BUG_message_3:
.string " msr=0x"
_BUG_message_4:
.string " dar=0x"
_BUG_message_5:
.string " dsisr=0x"
_BUG_message_6:
.string "\nStopping execution\n"
_excp_message_0x00:
.string "BIOS execution"
_excp_message_0x01:
.string "Reset"
_excp_message_0x02:
.string "Machine check"
_excp_message_0x03:
.string "Data memory access"
_excp_message_0x04:
.string "Instruction fetch"
_excp_message_0x05:
.string "External"
_excp_message_0x06:
.string "Alignment"
_excp_message_0x07:
.string "Program"
_excp_message_0x08:
.string "No floating point"
_excp_message_0x09:
.string "Decrementer"
_excp_message_0x0a:
.string "Reserved A"
_excp_message_0x0b:
.string "Reserved B"
_excp_message_0x0c:
.string "System call"
_excp_message_0x0d:
.string "Trace"
_excp_message_0x0e:
.string "Floating point assist"
_excp_message_0x0f:
.string "Performance monitor"
_excp_message_0x10:
.string "Instruction TLB miss"
_excp_message_0x11:
.string "Data TLB miss for store"
_excp_message_0x12:
.string "Data TLB miss for load"
_excp_message_0x13:
.string "Instruction address breakpoint"
_excp_message_0x14:
.string "System management"
_excp_message_0x15:
.string "Thermal management"
_excp_message_0x16:
.string "Unknown"
_messages_table:
.long _BUG_message_0
.long _BUG_message_1
.long _BUG_message_2
.long _BUG_message_3
.long _BUG_message_4
.long _BUG_message_5
.long _BUG_message_6
_excp_messages_table:
.long _excp_message_0x00
.long _excp_message_0x01
.long _excp_message_0x02
.long _excp_message_0x03
.long _excp_message_0x04
.long _excp_message_0x05
.long _excp_message_0x06
.long _excp_message_0x07
.long _excp_message_0x08
.long _excp_message_0x09
.long _excp_message_0x0a
.long _excp_message_0x0b
.long _excp_message_0x0c
.long _excp_message_0x0d
.long _excp_message_0x0e
.long _excp_message_0x0f
.long _excp_message_0x10
.long _excp_message_0x11
.long _excp_message_0x12
.long _excp_message_0x13
.long _excp_message_0x14
.long _excp_message_0x15
.long _excp_message_0x16
_last_excp_message:
bios_base:
.long BIOS_BASE
bios_size:
.long BIOS_SIZE / 4
_dummy_0:
.long 0x00000000
registers_area: /* To be loaded in register when an exception is caught */
_serial_IO: /* r27 */
.long 0x800003F8
_messages_start: /* r28 */
.long _messages_table - 4
_excp_messages: /* r29 */
.long _excp_messages_table
_max_excp: /* r30 */
.long (_last_excp_message - _excp_messages_table) / 4
_dummy_1: /* r31: dummy */
.long 0x00000000
.section .data
.align 2
save_area: /* Area for r11 save when an exception is skipped */
.long 0x00000000