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Implement op 0x00-0x08

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This commit is contained in:
Takashi Toyoshima 2014-12-06 21:00:22 +09:00
parent dd372c8a2d
commit ef36502777
1 changed files with 144 additions and 29 deletions
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173
6502.S
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@ -52,7 +52,16 @@
bl cpu6502_store
.endm
.macro _push16 reg
.macro _pushb reg
mov r0, SP
mov r1, \reg
_stb
mov r0, SP
subs r0, r0, #1
mov SP, r0
.endm
.macro _pushw reg
mov r0, SP
mov r1, \reg
lsrs r1, r1, #8
@ -76,32 +85,109 @@
_ldb
.endm
.macro _clx flag
.macro _fromIndexedIndirect
_fromImm8
mov r1, RX
adds r0, r0, R1
uxtb r0, r0
mov T0, r0
_ldb
mov T1, r0
adds r0, T0, #1
uxtb r0, r0
_ldb
lsls r0, r0, #8
adds r0, r0, T1
_ldb
.endm
.macro _fromZero
_fromImm8
_ldb
.endm
.macro _toZero
_fromImm8
mov r1, T0
_stb
.endm
.macro __cl flag
movs T0, #\flag
bics SR, SR, T0
.endm
.macro __se flag
movs T0, #\flag
orrs SR, SR, T0
.endm
.macro _clx flag
__cl \flag
adds PC, PC, #1
.endm
.macro _sex flag
movs T0, #\flag
orrs SR, SR, T0
__se \flag
adds PC, PC, #1
.endm
.macro _ld reg
_clx (FLAG_N | FLAG_Z)
mov \reg, r0
beq 1f
_sex FLAG_Z
.macro _flag_nz
__cl (FLAG_N | FLAG_Z)
movs r0, r0
bne 1f
__se FLAG_Z
1:
movs r1, #0x80
tst r0, r1
beq 1f
_sex FLAG_N
__se FLAG_N
1:
.endm
.macro _ld reg
mov \reg, r0
_flag_nz
adds PC, PC, #1
.endm
.macro _lop op
mov r1, RA
\op r0, r1, r0
mov RA, r0
_flag_nz
adds PC, PC, #1
.endm
.macro _asl
__cl (FLAG_N | FLAG_Z | FLAG_C)
movs r1, #0x80
tst r0, r1
beq 1f
bics r0, r0, r1
__se FLAG_C
1:
lsls r0, r0, #1
bne 1f
__se FLAG_Z
1:
tst r0, r1
beq 1f
__se FLAG_N
1:
adds PC, PC, #1
.endm
.macro _nop
adds PC, PC, #1
.endm
.macro _bxx
_fromImm8
sxtb r0, r0
add PC, PC, r0
.endm
.macro _resume
ldr r0, =#r_pc
ldr PC, [r0]
@ -141,24 +227,46 @@
str T0, [r0]
.endm
op00:
b quit
op01:
b quit
// NOP
op02:
b quit
op03:
b quit
op04:
b quit
op05:
b quit
op06:
b quit
op07:
b quit
op08:
b quit
_nop
_decode
op00: // BRK
adds T0, PC, #2
_pushw T0
_pushb SR
movs r0, #0xff
lsls r0, r0, #8
adds r0, r0, #0xfe
_ldw
mov PC, r0
_decode
op01: // ORA - (Indirect, X)
_fromIndexedIndirect
_lop orrs
_decode
op05: // ORA - Zero Page
_fromZero
_lop orrs
_decode
op06: // ASL - Zero Page
_fromZero
_asl
_toZero
_decode
op08: // PHP
_pushb SR
adds PC, PC, #1
_decode
op09:
b quit
op0a:
@ -208,7 +316,7 @@ op1f:
b quit
op20: // JSR
adds T0, PC, #2
_push16 T0
_pushw T0
adds r0, PC, #1
_ldw
mov PC, r0
@ -414,8 +522,10 @@ op82:
b quit
op83:
b quit
op84:
b quit
op84: // STY - Zero Page
mov T0, RY
_toZero
_decode
op85:
b quit
op86:
@ -573,8 +683,13 @@ opce:
b quit
opcf:
b quit
opd0:
b quit
opd0: // BNE (Z==0)
movs r0, #FLAG_Z
tst SR, r0
bne 1f
_bxx
1:
_decode
opd1:
b quit
opd2: