diff options
Diffstat (limited to 'libpsn00b/psxspu/transfer.s')
| -rw-r--r-- | libpsn00b/psxspu/transfer.s | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/libpsn00b/psxspu/transfer.s b/libpsn00b/psxspu/transfer.s new file mode 100644 index 0000000..aed69dc --- /dev/null +++ b/libpsn00b/psxspu/transfer.s @@ -0,0 +1,107 @@ +.set noreorder + +.include "hwregs_a.h" + + +.section .text + +.global SpuSetTransferMode +.type SpuSetTransferMode, @function +SpuSetTransferMode: + la $v0, _spu_transfer_mode + sb $a0, 0($v0) + jr $ra + move $v0, $a0 + + +.global SpuSetTransferStartAddr +.type SpuSetTransferStartAddr, @function +SpuSetTransferStartAddr: + li $v0, 0x1000 # Check if value is valid + blt $a0, $v0, .bad_value + nop + li $v0, 0xffff + bgt $a0, $v0, .bad_value + nop + + la $v1, _spu_transfer_addr + srl $v0, $a0, 3 # Set transfer destination address + sh $v0, 0($v1) + + jr $ra + move $v0, $a0 + +.bad_value: + jr $ra + move $v0, $0 + + +.global SpuWrite +.type SpuWrite, @function +SpuWrite: + addiu $sp, -8 + sw $ra, 0($sp) + sw $a0, 4($sp) + + lui $a3, IOBASE + + lhu $v0, SPUCNT($a3) # Set transfer mode to Stop + nop + andi $v0, 0xffcf + sh $v0, SPUCNT($a3) + jal SpuCtrlSync + move $a0, $v0 + + la $v1, _spu_transfer_addr # Set SPU write address + lhu $v1, 0($v1) + nop + sh $v1, SPU_ADDR($a3) + + lhu $v0, SPUCNT($a3) # Set transfer mode to DMA write + nop + ori $v0, 0x20 + sh $v0, SPUCNT($a3) + #jal SpuCtrlSync # Locks up on most emulators (bit 5 in + #move $a0, $v0 # SPUSTAT likely not updating, seems to + # be okay to not wait for it on real HW) + + lw $a0, 4($sp) + +.dma_wait: # Wait for SPU to be ready for DMA + lhu $v0, SPUSTAT($a3) + nop + andi $v0, 0x400 # Bit 8 in SPUSTAT never changes to 1 on + bnez $v0, .dma_wait # emulators so use bit 10 instead + nop + + sw $a0, D4_MADR($a3) # Set DMA source address + + li $v0, 0x10 # 16 words per block (64 bytes) + addiu $a1, 63 # Add by 63 to ensure all bytes get sent + srl $a1, 6 # Equivalent to divide by 64 + andi $a1, 0xffff + sll $a1, 16 + or $v0, $a1 + sw $v0, D4_BCR($a3) + + lui $v0, 0x0100 # Commence transfer + ori $v0, 0x0201 + sw $v0, D4_CHCR($a3) + + lw $ra, 0($sp) + addiu $sp, 8 + jr $ra + nop + + +.section .data + +.global _spu_transfer_mode +.type _spu_transfer_mode, @object +_spu_transfer_mode: + .word 0x0 + +.global _spu_transfer_addr +.type _spu_transfer_addr, @object +_spu_transfer_addr: + .word 0x200
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