First commit

1 files changed, 223 insertions, 0 deletions

diff --git a/libpsn00b/psxgpu/resetgraph.s b/libpsn00b/psxgpu/resetgraph.s
new file mode 100644
index 0000000..bc30d3b
--- /dev/null
+++ b/libpsn00b/psxgpu/resetgraph.s
@@ -0,0 +1,223 @@
+.set noreorder
+.set noat
+
+.include "hwregs_a.h"
+
+.section .text
+
+
+.global ResetGraph						# Resets the GPU and installs a
+.type ResetGraph, @function				# VSync event handler
+ResetGraph:
+	addiu	$sp, -0x20					# C style stack allocation (required if
+	sw		$ra, 28($sp)				# you call BIOS functions from asm)
+	sw		$a0, 24($sp)
+
+	la		$v0, _hooks_installed		# Skip installing hooks if this function
+	lbu		$v0, 0($v0)					# has already been called before once
+	nop
+	bnez	$v0, .skip_hook_init
+	nop
+
+	# Temporary, may help improve compatibility?
+	jal		SetDefaultExitFromException
+	nop
+
+	jal		ChangeClearPAD				# Remove pad handler left by the BIOS
+	move	$a0, $0
+
+	li		$a0, 1
+	jal		ChangeClearRCnt				# Remove RCnt handler
+	move	$a1, $0
+
+	jal		_96_remove					# Remove CD handling left by the BIOS
+	nop
+
+	lui		$a3, 0x1f80					# Base address for I/O
+
+	lui		$v0, 0x3b33					# Enables DMA channel 6 (for ClearOTag)
+	ori		$v0, 0x3b33					# Enables DMA channel 2
+	sw		$v0, DPCR($a3)
+	sw		$0 , DICR($a3)				# Clear DICR (not needed)
+
+	li		$v0, 0x9					# Enable IRQ0 (vblank)
+	sw		$v0, IMASK($a3)
+
+	# Set an event handler
+
+	li		$a0, 0xf2000003				# RCntCNT3 (vsync class)
+	li		$a1, 0x2
+	li		$a2, 0x1000
+	la		$a3, _vsync_func			# VSync event handler
+
+	jal		OpenEvent					# Open a VSync event handler
+										# (PSXSDK style vsync handler)
+	nop
+
+	la		$v1, _vsync_event_desc		# Save event descriptor
+	sw		$v0, 0($v1)
+
+	jal		EnableEvent					# Enable the opened event
+	move	$a0, $v0
+
+	la		$v0, _hooks_installed		# Set installed flag
+	li		$v1, 0x1
+	sb		$v1, 0($v0)
+
+	la		$v0, _vsync_counter			# Clear VSync counter
+	sw		$0 , 0($v0)
+
+	la		$v0, _vsync_callback_func	# Clear callback function
+	sw		$0 , 0($v0)
+
+	jal		ExitCriticalSection			# Re-enable interrupts
+	nop
+
+.skip_hook_init:
+	
+	lui		$a3, 0x1f80
+
+	lw		$v0, GP1($a3)				# Get video standard
+	lui		$v1, 0x0010
+	and		$v0, $v1
+	la		$v1, _gpu_standard
+	beqz	$v0, .not_pal
+	sw		$0 , 0($v1)
+	li		$v0, 1
+	sw		$v0, 0($v1)
+.not_pal:
+
+	lw		$a0, 24($sp)				# Get argument value
+
+	lui		$a3, 0x1f80					# Set base I/O again (likely destroyed
+										# by previous calls)
+
+	li		$v0, 0x1d00					# Configure timer 1 as Hblank counter
+	sw		$v0, T1_MODE($a3)			# Set timer 1 value
+
+	li		$at, 1
+	beq		$a0, $at, .gpu_init_1
+	nop
+	li		$at, 3
+	beq		$a0, $at, .gpu_init_3
+	nop
+
+	sw		$0 , GP1($a3)				# Reset the GPU
+
+	b		.init_done
+	nop
+
+.gpu_init_1:
+
+	sw		$0 , D2_CHCR($a3)			# Stop any DMA
+
+.gpu_init_3:
+
+	li		$v0, 0x1					# Reset the command buffer
+	sw		$v0, GP1($a3)
+
+.init_done:
+
+	lw		$ra, 28($sp)
+	lw		$a0, 24($sp)				# Return
+	jr		$ra
+	addiu	$sp, 0x20
+
+
+.global _vsync_func						# VSync event handler, executed on
+.type _vsync_func, @function			# every VBlank
+_vsync_func:
+
+	la		$gp, _gp
+
+	lui		$at, 0x1f80					# Check if there's a VSync IRQ
+	lw		$v0, IMASK($at)
+	nop
+	andi	$v0, $v0, 0x1
+	beqz	$v0, .exit
+	nop
+
+	lw		$v1, ISTAT($at)
+	nop
+	andi	$v0, $v1, 0x1
+	beqz	$v0, .exit
+	nop
+	xori	$v1, $v1, 0x1				# Acknowledge the IRQ
+	sw		$v1, ISTAT($at)
+
+	la		$v1, _vsync_counter			# Increment VSync counter
+	lw		$v0, 0($v1)
+	nop
+	addiu	$v0, 1
+	sw		$v0, 0($v1)
+
+	la		$v0, _vsync_callback_func	# Check if a callback function is set
+	lw		$v0, 0($v0)
+	nop
+	beqz	$v0, .exit
+	nop
+
+	addiu	$sp, -0x20					# Save return address
+	sw		$ra, 28($sp)
+
+	jalr	$v0							# Execute user function
+	nop
+
+	lw		$ra, 28($sp)				# Restore previous return address
+	addiu	$sp, 0x20
+
+.exit:
+	jr      $ra
+	nop
+
+
+.global VSync							# VSync function
+.type VSync, @function
+VSync:
+	addiu	$sp, -4
+	sw		$ra, 0($sp)
+
+	la		$a1, _vsync_counter
+	lw		$v0, 0($a1)
+	nop
+.loop:
+	lw		$v1, 0($a1)
+	nop
+	beq		$v0, $v1, .loop
+	nop
+
+	la		$v0, _gpu_current_field		# Get last field value
+	lbu		$v1, 0($v0)
+.wait_field:							# Wait for field bit to change
+	jal		ReadGPUstat
+	nop
+	srl		$v0, 31
+	beq		$v0, $v1, .wait_field
+	nop
+
+	la		$v1, _gpu_current_field		# Store new field value
+	sb		$v0, 0($v1)
+
+	lw		$ra, 0($sp)
+	addiu	$sp, 4
+	jr		$ra
+	nop
+
+
+.section .data
+
+.global library_credits
+.type library_credits, @object
+library_credits:
+	.string "psxgpu programs by Lameguy64"
+
+.type _vsync_counter, @object
+_vsync_counter:
+	.word 0
+
+.comm	_vsync_callback_func, 4, 4
+.comm	_vsync_event_desc, 4, 4
+
+.comm	_gpu_standard, 4, 4
+.comm	_gpu_current_field, 4, 4
+.comm	_hooks_installed, 4, 4