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entry.S
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#include "param.h"
.section .start, "ax"
.global start
start:
/* initialize the cache */
mov.l CCR_REG, r0
mov.l CCR_INIT, r1
mov.l r1, @r0
/* initialize status registers */
mov.l SR_INIT, r1
ldc r1, sr
/* initialize bss */
mov.l BSS_END, r1
mov.l BSS_START, r2
mov #0, r0
1:
movca.l r0, @r2
mov.l r0, @(4,r2)
mov.l r0, @(8,r2)
mov.l r0, @(12,r2)
mov.l r0, @(16,r2)
mov.l r0, @(20,r2)
mov.l r0, @(24,r2)
mov.l r0, @(28,r2)
add #32, r2
cmp/hs r1, r2
bf 1b
/* initialize stack point */
mov.l XV6_STACK, r0
mov r0, r15
/* initialize vector base register */
mov.l VBR_INIT, r0
ldc r0, vbr
mov.l XV6_MAIN, r0
jmp @r0
nop
.align 4
CCR_REG:
.long 0xff00001c
CCR_INIT:
.long 0x90b
SR_INIT:
.long 0x50000000
VBR_INIT:
.long start
BSS_START:
.long __bss_start
BSS_END:
.long __bss_end
XV6_MAIN:
.long main
XV6_STACK:
.long xv6_stack+STACK_SIZE
/****************************************************************
* *
* general exception handler (VBR + 0x100) *
* *
****************************************************************/
.balign 256, 0, 256
general_exception:
/*
* kernel stack -> kernel stack (no change)
* user stack -> kernel stack (change)
*/
stc ssr, r15
shll r15
shll r15
bt/s excp_no_change ! SR.MD == 1 ?
stc sgr, r15
/* current stack = r15 = proc->kstack + KSTACKSIZE */
mov.l r2, @-r15
mov.l r1, @-r15
mov.l excp_proc, r1
mov.l @r1, r1
mov.l @(8,r1), r1 ! XXX: better way to locate proc->kstack?
mov.l excp_STACK_SIZE, r2
add r2, r1
mov r15, r2 ! r2 = old stack
mov r1, r15 ! r15 = new stack
mov.l @r2+, r1
mov.l @r2+, r2
excp_no_change:
/* save trapframe */
sts.l pr, @-r15
sts.l macl, @-r15
sts.l mach, @-r15
stc.l gbr, @-r15
stc.l sgr, @-r15
stc.l ssr, @-r15
stc.l spc, @-r15
mov.l r14, @-r15
mov.l r13, @-r15
mov.l r12, @-r15
mov.l r11, @-r15
mov.l r10, @-r15
mov.l r9, @-r15
mov.l r8, @-r15
mov.l r7, @-r15
mov.l r6, @-r15
mov.l r5, @-r15
mov.l r4, @-r15
mov.l r3, @-r15
mov.l r2, @-r15
mov.l r1, @-r15
mov.l r0, @-r15
/* save EXPEVT */
mov.l excp_EXPEVT, r4
mov.l @r4, r4
#if 0
/* enable intr */
stc sr, r1
mov.l excp_SR_BL_ENABLE, r2
and r1, r2
ldc r2, sr
#endif
/* call the service routine */
mov.l excp_vect_table, r1
shlr2 r4
shlr r4
add r4, r1 ! r1 = vect_table + EXPEVT >> 2
mov.l @r1, r1
jsr @r1
nop
#if 0
/* disable intr */
stc sr, r1
mov.l excp_SR_BL_DISABLE, r2
or r1, r2
ldc r2, sr
#endif
/* restore trapframe */
.global trapret
trapret:
#if 0
stc r0_bank, r5
mov.l excp_debug_str, r4
mov.l excp_cprintf, r1
jsr @r1
nop
#endif
mov.l @r15+, r0
mov.l @r15+, r1
mov.l @r15+, r2
mov.l @r15+, r3
mov.l @r15+, r4
mov.l @r15+, r5
mov.l @r15+, r6
mov.l @r15+, r7
mov.l @r15+, r8
mov.l @r15+, r9
mov.l @r15+, r10
mov.l @r15+, r11
mov.l @r15+, r12
mov.l @r15+, r13
mov.l @r15+, r14
ldc.l @r15+, spc
ldc.l @r15+, ssr
! ldc.l @r15+, sgr ! forbidden
add #4, r15
ldc.l @r15+, gbr
lds.l @r15+, mach
lds.l @r15+, macl
lds.l @r15+, pr
/* return */
! stc sgr, r15
add #-20, r15
mov.l @r15, r15
rte
nop
#ifdef DEBUG
mov r15, r5
mov.l excp_debug_str, r4
mov.l excp_cprintf, r1
jsr @r1
nop
debug_loop_excp:
bra debug_loop_excp
nop
#endif
.align 4
excp_EXPEVT:
.long 0xff000024
excp_cprintf:
.long cprintf
excp_debug_str:
.long debug_str
excp_SR_MD:
.long 0x40000000
excp_SR_BL_ENABLE:
.long 0xefffffff
excp_SR_BL_DISABLE:
.long 0x10000000
excp_proc:
.long proc
excp_vect_table:
.long vect_table
excp_STACK_SIZE:
.long KSTACKSIZE
/****************************************************************
* *
* tlb exception handler (VBR + 0x400) *
* *
****************************************************************/
.balign 1024, 0, 1024
tlb_exception:
/*
* user stack -> kernel stack
*/
/* current stack = r15 = proc->kstack + KSTACKSIZE */
mov.l tlb_tmp_stack, r15
mov.l r2, @-r15
mov.l r1, @-r15
mov.l tlb_proc, r1
mov.l @r1, r1
mov.l @(8,r1), r1 ! XXX: better way to locate proc->kstack?
mov.l tlb_STACK_SIZE, r2
add r2, r1
mov r15, r2 ! r2 = old stack
mov r1, r15 ! r15 = new stack
mov.l @r2+, r1
mov.l @r2+, r2
/* save trapframe */
sts.l pr, @-r15
sts.l macl, @-r15
sts.l mach, @-r15
stc.l gbr, @-r15
stc.l sgr, @-r15
stc.l ssr, @-r15
stc.l spc, @-r15
mov.l r14, @-r15
mov.l r13, @-r15
mov.l r12, @-r15
mov.l r11, @-r15
mov.l r10, @-r15
mov.l r9, @-r15
mov.l r8, @-r15
mov.l r7, @-r15
mov.l r6, @-r15
mov.l r5, @-r15
mov.l r4, @-r15
mov.l r3, @-r15
mov.l r2, @-r15
mov.l r1, @-r15
mov.l r0, @-r15
/* save EXPEVT */
mov.l tlb_EXPEVT, r4
mov.l @r4, r4
/* XXX: enable intr */
/* call the service routine */
mov.l tlb_vect_table, r1
shlr2 r4
shlr r4
add r4, r1 ! r1 = vect_table + EXPEVT >> 2
mov.l @r1, r1
jsr @r1
nop
/* restore trapframe */
mov.l @r15+, r0
mov.l @r15+, r1
mov.l @r15+, r2
mov.l @r15+, r3
mov.l @r15+, r4
mov.l @r15+, r5
mov.l @r15+, r6
mov.l @r15+, r7
mov.l @r15+, r8
mov.l @r15+, r9
mov.l @r15+, r10
mov.l @r15+, r11
mov.l @r15+, r12
mov.l @r15+, r13
mov.l @r15+, r14
ldc.l @r15+, spc
ldc.l @r15+, ssr
! ldc.l @r15+, sgr ! forbidden
add #4, r15
ldc.l @r15+, gbr
lds.l @r15+, mach
lds.l @r15+, macl
lds.l @r15+, pr
/* return */
! stc sgr, r15
add #-20, r15
mov.l @r15, r15
rte
nop
#ifdef DEBUG
mov r15, r5
mov.l tlb_debug_str, r4
mov.l tlb_cprintf, r1
jsr @r1
nop
debug_loop_tlb:
bra debug_loop_tlb
nop
#endif
.align 4
tlb_EXPEVT:
.long 0xff000024
tlb_cprintf:
.long cprintf
tlb_debug_str:
.long debug_str
tlb_SR_MD:
.long 0x40000000
tlb_proc:
.long proc
tlb_vect_table:
.long vect_table
tlb_STACK_SIZE:
.long KSTACKSIZE
tlb_tmp_stack:
.long xv6_stack + STACK_SIZE
/****************************************************************
* *
* interrupt handler (VBR + 0x600) *
* *
****************************************************************/
.balign 512, 0, 512
intr_entry:
/*
* kernel stack -> kernel stack (no change)
* user stack -> kernel stack (change)
*/
stc ssr, r15
shll r15
shll r15
bt/s intr_no_change ! SR.MD == 1 ?
stc sgr, r15
/* current stack = r15 = proc->kstack + KSTACKSIZE */
mov.l r2, @-r15
mov.l r1, @-r15
mov.l intr_proc, r1
mov.l @r1, r1
mov.l @(8,r1), r1 ! XXX: better way to locate proc->kstack?
mov.l intr_STACK_SIZE, r2
add r2, r1
mov r15, r2 ! r2 = old stack
mov r1, r15 ! r15 = new stack
mov.l @r2+, r1
mov.l @r2+, r2
intr_no_change:
/* save trapframe */
sts.l pr, @-r15
sts.l macl, @-r15
sts.l mach, @-r15
stc.l gbr, @-r15
stc.l sgr, @-r15
stc.l ssr, @-r15
stc.l spc, @-r15
mov.l r14, @-r15
mov.l r13, @-r15
mov.l r12, @-r15
mov.l r11, @-r15
mov.l r10, @-r15
mov.l r9, @-r15
mov.l r8, @-r15
mov.l r7, @-r15
mov.l r6, @-r15
mov.l r5, @-r15
mov.l r4, @-r15
mov.l r3, @-r15
mov.l r2, @-r15
mov.l r1, @-r15
mov.l r0, @-r15
/* save EXPEVT */
mov.l intr_INTEVT, r4
mov.l @r4, r4
/* XXX: enbale intr */
/* call the service routine */
mov.l intr_vect_table, r1
shlr2 r4
shlr r4
add r4, r1 ! r1 = vect_table + INTEVT >> 2
mov.l @r1, r1
jsr @r1
nop
/* restore trapframe */
mov.l @r15+, r0
mov.l @r15+, r1
mov.l @r15+, r2
mov.l @r15+, r3
mov.l @r15+, r4
mov.l @r15+, r5
mov.l @r15+, r6
mov.l @r15+, r7
mov.l @r15+, r8
mov.l @r15+, r9
mov.l @r15+, r10
mov.l @r15+, r11
mov.l @r15+, r12
mov.l @r15+, r13
mov.l @r15+, r14
ldc.l @r15+, spc
ldc.l @r15+, ssr
! ldc.l @r15+, sgr ! forbidden
add #4, r15
ldc.l @r15+, gbr
lds.l @r15+, mach
lds.l @r15+, macl
lds.l @r15+, pr
/* return */
! stc sgr, r15
add #-20, r15
mov.l @r15, r15
rte
nop
.align 4
intr_INTEVT:
.long 0xff000028
intr_cprintf:
.long cprintf
intr_debug_str:
.long debug_str
intr_SR_MD:
.long 0x40000000
intr_proc:
.long proc
intr_vect_table:
.long vect_table
intr_STACK_SIZE:
.long KSTACKSIZE