5b69777647
GNU as has "la %r4,8(%r3)" as an alias for "addi %r4,%r3,8", meaning to load the address of the thing at 8(%r3). Our 'la', now 'li32', makes an addis/ori pair to load an immediate 32-bit value. For example, "li32 r4,23456789" loads a big number.
106 lines
1.8 KiB
ArmAsm
106 lines
1.8 KiB
ArmAsm
#
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! $Source: /cvsroot/tack/Ack/plat/linux386/libsys/_syscall.s,v $
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! $State: Exp $
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! $Revision: 1.1 $
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! Declare segments (the order is important).
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.sect .text
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.sect .rom
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.sect .data
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.sect .bss
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.sect .text
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#define IFFALSE 4
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#define IFTRUE 12
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#define ALWAYS 20
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#define LT 0
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#define GT 1
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#define EQ 2
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#define OV 3
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EARRAY = 0
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ERANGE = 1
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ESET = 2
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EIOVFL = 3
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EFOVFL = 4
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EFUNFL = 5
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EIDIVZ = 6
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EFDIVZ = 7
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EIUND = 8
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EFUND = 9
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ECONV = 10
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ESTACK = 16
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EHEAP = 17
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EILLINS = 18
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EODDZ = 19
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ECASE = 20
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EMEMFLT = 21
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EBADPTR = 22
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EBADPC = 23
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EBADLAE = 24
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EBADMON = 25
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EBADLIN = 26
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EBADGTO = 27
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EUNIMPL = 63 ! unimplemented em-instruction called
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! EM trap handling.
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.define .trap_ecase
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.trap_ecase:
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addi r3, r0, ECASE
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b .trap
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.define .trap_earray
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.trap_earray:
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addi r3, r0, EARRAY
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b .trap
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.define .trap
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.trap:
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cmpi cr0, 0, r3, 15 ! traps >15 can't be ignored
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bc IFTRUE, LT, 1f
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addi r4, r0, 1
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rlwnm r4, r4, r3, 0, 31 ! calculate trap bit
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li32 r5, .ignmask
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lwz r5, 0(r5) ! load ignore mask
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and. r4, r4, r5 ! compare
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bclr IFFALSE, EQ, 0 ! return if non-zero
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1:
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li32 r4, .trppc
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lwz r5, 0(r4) ! load user trap routine
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or. r5, r5, r5 ! test
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bc IFTRUE, EQ, fatal ! if no user trap routine, bail out
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addi r0, r0, 0
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stw r0, 0(r4) ! reset trap routine
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mfspr r0, lr
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stwu r0, -4(sp) ! save old lr
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stwu r3, -4(sp)
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mtspr ctr, r5
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bcctrl ALWAYS, 0, 0 ! call trap routine
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lwz r0, 4(sp) ! load old lr again
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addi sp, sp, 8 ! retract over stack usage
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bclr ALWAYS, 0, 0 ! return
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fatal:
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addi r3, r0, 1
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li32 r4, message
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addi r5, r0, 6
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addi r0, r0, 4 ! write()
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sc 0
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addi r0, r0, 1 ! exit()
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sc 0
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.sect .rom
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message:
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.ascii "TRAP!\n"
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