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- /*
- * PicoDrive
- * (C) notaz, 2006-2009
- *
- * This work is licensed under the terms of MAME license.
- * See COPYING file in the top-level directory.
- */
- #include "pico_int_o32.h"
- .equ SRR_MAPPED, (1 << 0)
- .equ SRR_READONLY, (1 << 1)
- .equ SRF_EEPROM, (1 << 1)
- .equ POPT_EN_32X, (1 << 20)
- .text
- .align 4
- .global PicoRead8_sram
- .global PicoRead8_io
- .global PicoRead16_sram
- .global PicoRead16_io
- .global PicoWrite8_io
- .global PicoWrite16_io
- PicoRead8_sram: @ u32 a
- ldr r3, =Pico
- ldr r1, [r3, #OFS_Pico_sv_end]
- cmp r0, r1
- bgt m_read8_nosram
- ldr r2, [r3, #OFS_Pico_sv_start]
- cmp r0, r2
- blt m_read8_nosram
- ldrb r1, [r3, #OFS_Pico_m_sram_reg]
- tst r1, #SRR_MAPPED
- beq m_read8_nosram
- ldr r1, [r3, #OFS_Pico_sv_flags]
- tst r1, #SRF_EEPROM
- bne m_read8_eeprom
- ldr r1, [r3, #OFS_Pico_sv_data]
- sub r0, r0, r2
- ldrb r0, [r0, r1]
- bx lr
- m_read8_nosram:
- ldr r1, [r3, #OFS_Pico_romsize]
- cmp r0, r1
- movgt r0, #0
- bxgt lr @ bad location
- @ XXX: banking unfriendly
- ldr r1, [r3, #OFS_Pico_rom]
- eor r0, r0, #1
- ldrb r0, [r1, r0]
- bx lr
- m_read8_eeprom:
- stmfd sp!,{r0,lr}
- bl EEPROM_read
- ldmfd sp!,{r1,lr}
- tst r1, #1
- moveq r0, r0, lsr #8
- bx lr
- PicoRead8_io: @ u32 a
- bic r2, r0, #0x001f @ most commonly we get i/o port read,
- cmp r2, #0xa10000 @ so check for it first
- beq io_ports_read
- m_read8_not_io:
- and r2, r0, #0xfc00
- cmp r2, #0x1000
- bne m_read8_not_brq
- ldr r3, =Pico
- mov r1, r0
- ldr r0, [r3, #OFS_Pico_m_rotate]
- add r0, r0, #1
- strb r0, [r3, #OFS_Pico_m_rotate]
- eor r0, r0, r0, lsl #6
- tst r1, #1
- bxne lr @ odd addr -> open bus
- bic r0, r0, #1 @ bit0 defined in this area
- and r2, r1, #0xff00
- cmp r2, #0x1100
- bxne lr @ not busreq
- ldrb r1, [r3, #OFS_Pico_m_z80Run]
- ldrb r2, [r3, #OFS_Pico_m_z80_reset]
- orr r0, r0, r1
- orr r0, r0, r2
- bx lr
- m_read8_not_brq:
- ldr r2, =PicoOpt
- ldr r2, [r2]
- tst r2, #POPT_EN_32X
- bne PicoRead8_32x
- mov r0, #0
- bx lr
- @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
- PicoRead16_sram: @ u32 a, u32 d
- ldr r3, =Pico
- ldr r1, [r3, #OFS_Pico_sv_end]
- cmp r0, r1
- bgt m_read16_nosram
- ldr r2, [r3, #OFS_Pico_sv_start]
- cmp r0, r2
- blt m_read16_nosram
- ldrb r1, [r3, #OFS_Pico_m_sram_reg]
- tst r1, #SRR_MAPPED
- beq m_read16_nosram
- ldr r1, [r3, #OFS_Pico_sv_flags]
- tst r1, #SRF_EEPROM
- bne EEPROM_read
- ldr r1, [r3, #OFS_Pico_sv_data]
- sub r0, r0, r2
- ldrb r1, [r0, r1]!
- ldrb r0, [r0, #1]
- orr r0, r0, r1, lsl #8
- bx lr
- m_read16_nosram:
- ldr r1, [r3, #OFS_Pico_romsize]
- cmp r0, r1
- movgt r0, #0
- bxgt lr @ bad location
- @ XXX: banking unfriendly
- ldr r1, [r3, #OFS_Pico_rom]
- ldrh r0, [r1, r0]
- bx lr
- PicoRead16_io: @ u32 a, u32 d
- bic r2, r0, #0x001f @ most commonly we get i/o port read,
- cmp r2, #0xa10000 @ so check for it first
- bne m_read16_not_io
- stmfd sp!,{lr}
- bl io_ports_read @ same as read8
- orr r0, r0, r0, lsl #8 @ only has bytes mirrored
- ldmfd sp!,{pc}
- m_read16_not_io:
- and r2, r0, #0xfc00
- cmp r2, #0x1000
- bne m_read16_not_brq
- ldr r3, =Pico
- and r2, r0, #0xff00
- ldr r0, [r3, #OFS_Pico_m_rotate]
- add r0, r0, #1
- strb r0, [r3, #OFS_Pico_m_rotate]
- eor r0, r0, r0, lsl #5
- eor r0, r0, r0, lsl #8
- bic r0, r0, #0x100 @ bit8 defined in this area
- cmp r2, #0x1100
- bxne lr @ not busreq
- ldrb r1, [r3, #OFS_Pico_m_z80Run]
- ldrb r2, [r3, #OFS_Pico_m_z80_reset]
- orr r0, r0, r1, lsl #8
- orr r0, r0, r2, lsl #8
- bx lr
- m_read16_not_brq:
- ldr r2, =PicoOpt
- ldr r2, [r2]
- tst r2, #POPT_EN_32X
- bne PicoRead16_32x
- mov r0, #0
- bx lr
- @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
- PicoWrite8_io: @ u32 a, u32 d
- bic r2, r0, #0x1e @ most commonly we get i/o port write,
- eor r2, r2, #0xa10000 @ so check for it first
- eors r2, r2, #1
- beq io_ports_write
- m_write8_not_io:
- tst r0, #1
- bne m_write8_not_z80ctl @ even addrs only
- and r2, r0, #0xff00
- cmp r2, #0x1100
- moveq r0, r1
- beq ctl_write_z80busreq
- cmp r2, #0x1200
- moveq r0, r1
- beq ctl_write_z80reset
- m_write8_not_z80ctl:
- @ unlikely
- eor r2, r0, #0xa10000
- eor r2, r2, #0x003000
- eors r2, r2, #0x0000f1
- bne m_write8_not_sreg
- ldr r3, =Pico
- ldrb r2, [r3, #OFS_Pico_m_sram_reg]
- and r1, r1, #(SRR_MAPPED|SRR_READONLY)
- bic r2, r2, #(SRR_MAPPED|SRR_READONLY)
- orr r2, r2, r1
- strb r2, [r3, #OFS_Pico_m_sram_reg]
- bx lr
- m_write8_not_sreg:
- ldr r2, =PicoOpt
- ldr r2, [r2]
- tst r2, #POPT_EN_32X
- bne PicoWrite8_32x
- bx lr
- @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
- PicoWrite16_io: @ u32 a, u32 d
- bic r2, r0, #0x1f @ most commonly we get i/o port write,
- cmp r2, #0xa10000 @ so check for it first
- beq io_ports_write
- m_write16_not_io:
- and r2, r0, #0xff00
- cmp r2, #0x1100
- moveq r0, r1, lsr #8
- beq ctl_write_z80busreq
- cmp r2, #0x1200
- moveq r0, r1, lsr #8
- beq ctl_write_z80reset
- m_write16_not_z80ctl:
- @ unlikely
- eor r2, r0, #0xa10000
- eor r2, r2, #0x003000
- eors r2, r2, #0x0000f0
- bne m_write16_not_sreg
- ldr r3, =Pico
- ldrb r2, [r3, #OFS_Pico_m_sram_reg]
- and r1, r1, #(SRR_MAPPED|SRR_READONLY)
- bic r2, r2, #(SRR_MAPPED|SRR_READONLY)
- orr r2, r2, r1
- strb r2, [r3, #OFS_Pico_m_sram_reg]
- bx lr
- m_write16_not_sreg:
- ldr r2, =PicoOpt
- ldr r2, [r2]
- tst r2, #POPT_EN_32X
- bne PicoWrite16_32x
- bx lr
- .pool
- @ vim:filetype=armasm
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