player/Project/Src/NES/6502cart_gcc.S

  .syntax unified
  .cpu cortex-m4
  .fpu softvfp
  .thumb
  .text


.include "6502def.s"



.extern NES_RAM
.extern NES_SRAM
.extern CPU_reset
.extern romfile
.extern cpu_data
.extern op_table

.global cpu6502_init
.global map67_
.global map89_
.global mapAB_
.global mapCD_
.global mapEF_



.type  cpu6502_init, %function
cpu6502_init:
  // ѹջ
  stmfd sp!,{r4-r11,lr}
  // <EFBFBD>Ѷ<EFBFBD>ȡcpu<EFBFBD><EFBFBD><EFBFBD><EFBFBD>
  ldr r10,=cpu_data
  // <EFBFBD><EFBFBD>NES_RAM<EFBFBD><EFBFBD>ַָ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ص<EFBFBD>r11<EFBFBD><EFBFBD>
  ldr r11,=NES_RAM
  ldr r11,[r11]

  // <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD>ӳ<EFBFBD><EFBFBD>
  str r11,[globalptr,#memmap_tbl]
  str r11,[globalptr,#memmap_tbl+4]
  str r11,[globalptr,#memmap_tbl+8]
  ldr r0,=NES_SRAM
  ldr r0,[r0]
  str r0,[globalptr,#memmap_tbl+12]

  // <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַָ<EFBFBD><EFBFBD>
  ldr r0,=op_table
  str r0,[globalptr,#opz]

  // <EFBFBD><EFBFBD><EFBFBD><EFBFBD>rom<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ
  ldr r0,=romfile
  ldr r0,[r0]                   // R0<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><EFBFBD>ROMӳ<EFBFBD>񣨰<EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD>
  add r3,r0,#16                 // r3<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><EFBFBD>rom<EFBFBD><EFBFBD><EFBFBD><EFBFBD>(<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD>
  str r3,[globalptr,#rombase]   // <EFBFBD><EFBFBD><EFBFBD><EFBFBD>rom<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ

  mov r2,#1
  ldrb r1,[r3,#-12]             // 16kB PROM<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ŀ     2
  rsb r0,r2,r1,lsl#14           // romsize=X*16KB   <<14 <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><EFBFBD>   r0=0x7fff
  str r0,[globalptr,#rommask]   // rommask=promsize-1   32768-1

  mov r9,#0                     // (<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>κ<EFBFBD>encodePC<EFBFBD><EFBFBD>ӳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>*<EFBFBD><EFBFBD>ʼ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>еĴ<EFBFBD><EFBFBD><EFBFBD>)
  str r9,[globalptr,#lastbank]  // 6502PC<EFBFBD><EFBFBD> ROM<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>д0

  mov r0,#0                     // Ĭ<EFBFBD><EFBFBD>romӳ<EFBFBD><EFBFBD>
  bl map89AB_                   // 89AB=1st 16k
  mov r0,#-1
  bl mapCDEF_                   // CDEF=last 16k

  ldrb r1,[r3,#-10]             // get mapper
  ldrb r2,[r3,#-9]
  tst r2,#0x0e                  // long live DiskDude!
  and r1,r1,#0xf0
  and r2,r2,#0xf0
  orr r0,r2,r1,lsr#4
  IT NE
  movne r0,r1,lsr#4             // ignore high nibble if header looks bad  <EFBFBD><EFBFBD><EFBFBD>Ը<EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
                                // r0=mapper<EFBFBD><EFBFBD>

  // <EFBFBD><EFBFBD><EFBFBD><EFBFBD>дrom<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><EFBFBD>
  ldr r0,=Mapper_W
  str r0,[globalptr,#writemem_tbl+16]
  str r0,[globalptr,#writemem_tbl+20]
  str r0,[globalptr,#writemem_tbl+24]
  str r0,[globalptr,#writemem_tbl+28]

  // cpu<EFBFBD><EFBFBD>λ
  bl CPU_reset
  ldmfd sp!,{r4-r11,lr}
  bx lr



.type  map67_, %function
map67_:  // rom paging.. r0=page#
  ldr r1,[globalptr,#rommask]
  and r0,r1,r0,lsl#13
  ldr r1,[globalptr,#rombase]
  add r0,r1,r0
  sub r0,r0,#0x6000
  str r0,[globalptr,#memmap_tbl+12]
  b flush

.type  map89_, %function
map89_:  // rom paging.. r0=page# ROM<EFBFBD><EFBFBD>ҳ
  ldr r1,[globalptr,#rombase]       // rom<EFBFBD><EFBFBD>ʼ<EFBFBD><EFBFBD>ַ
  sub r1,r1,#0x8000
  ldr r2,[globalptr,#rommask]
  and r0,r2,r0,lsl#13
  add r0,r1,r0
  str r0,[globalptr,#memmap_tbl+16]
  b flush

.type  mapAB_, %function
mapAB_:
  ldr r1,[globalptr,#rombase]
  sub r1,r1,#0xa000
  ldr r2,[globalptr,#rommask]
  and r0,r2,r0,lsl#13
  add r0,r1,r0
  str r0,[globalptr,#memmap_tbl+20]
  b flush

.type  mapCD_, %function
mapCD_:
  ldr r1,[globalptr,#rombase]
  sub r1,r1,#0xc000
  ldr r2,[globalptr,#rommask]
  and r0,r2,r0,lsl#13
  add r0,r1,r0
  str r0,[globalptr,#memmap_tbl+24]
  b flush

.type  mapEF_, %function
mapEF_:
  ldr r1,[globalptr,#rombase]
  sub r1,r1,#0xe000
  ldr r2,[globalptr,#rommask]
  and r0,r2,r0,lsl#13
  add r0,r1,r0
  str r0,[globalptr,#memmap_tbl+28]
  b flush

.type  map89AB_, %function
map89AB_:
  ldr r1,[globalptr,#rombase]       // rom<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD>
  sub r1,r1,#0x8000
  ldr r2,[globalptr,#rommask]
  and r0,r2,r0,lsl#14
  add r0,r1,r0
  str r0,[globalptr,#memmap_tbl+16]
  str r0,[globalptr,#memmap_tbl+20]

flush:    // update m6502_pc & lastbank
  ldr r1,[globalptr,#lastbank]
  sub r9,r9,r1
  and r1,r9,#0xE000     // //r9<EFBFBD><EFBFBD>0xe000<EFBFBD><EFBFBD>λ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
  add r2, globalptr,#memmap_tbl     // //<EFBFBD>Ѵ洢<EFBFBD><EFBFBD>ӳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD><EFBFBD><EFBFBD>ص<EFBFBD>r2
  lsr r1,r1,#11        // //>>11λ    r1/2048
  ldr r0,[r2,r1]        // //<EFBFBD><EFBFBD>ȡr2<EFBFBD><EFBFBD>ַ+r1ƫ<EFBFBD>Ƶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݵ<EFBFBD>r0

  str r0,[globalptr,#lastbank]        // //<EFBFBD><EFBFBD><EFBFBD><EFBFBD>6502PC<EFBFBD><EFBFBD> ROM<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>
  add r9,r9,r0  // //m6502_pc+r0
  orr lr,#0x01    // lr<EFBFBD><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><EFBFBD>1<EFBFBD><EFBFBD>ֹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>arm״̬
  bx lr

.type  mapCDEF_, %function
mapCDEF_:
  ldr r1,[globalptr,#rombase]
  sub r1,r1,#0xc000
  ldr r2,[globalptr,#rommask]
  and r0,r2,r0,lsl#14
  add r0,r1,r0
  str r0,[globalptr,#memmap_tbl+24]
  str r0,[globalptr,#memmap_tbl+28]
  b flush

.type  map89ABCDEF_, %function
map89ABCDEF_:
  ldr r1,[globalptr,#rombase]
  sub r1,r1,#0x8000
  ldr r2,[globalptr,#rommask]
  and r0,r2,r0,lsl#15
  add r0,r1,r0
  str r0,[globalptr,#memmap_tbl+16]
  str r0,[globalptr,#memmap_tbl+20]
  str r0,[globalptr,#memmap_tbl+24]
  str r0,[globalptr,#memmap_tbl+28]
  b flush


.extern asm_Mapper_Write
.type Mapper_W, %function
Mapper_W:
  stmfd sp!,{r3,lr}   // LR <EFBFBD>Ĵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ջ
  mov r1,r12
  bl asm_Mapper_Write
  ldmfd sp!,{r3,lr}
  orr lr,#0x01        // lr<EFBFBD><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><EFBFBD>1<EFBFBD><EFBFBD>ֹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>arm״̬
  bx lr



@ .global main
@ .type main, %function
@ mian:
@   b cpu6502_init