Added BIOS Controller, BIOS CD, 2 new examples and custom exit handler in the works

2 files changed, 81 insertions, 15 deletions

diff --git a/libpsn00b/psxgpu/readme.txt b/libpsn00b/psxgpu/readme.txt
index 55fcb68..0d44e72 100644
--- a/libpsn00b/psxgpu/readme.txt
+++ b/libpsn00b/psxgpu/readme.txt
@@ -27,7 +27,7 @@ Todo list:
 	  getting number of vsyncs elapsed and waiting until a specified number of
 	  vsyncs have passed.
 
-	* VSync interrupt handler should be hooked using BIOS function
+	* (old) VSync interrupt handler should be hooked using BIOS function
 	  SetCustomExitFromException() like the official GPU library instead of
 	  hooking an event handler, but said hook never seems to work. Perhaps
 	  something in the kernel area needs to be patched/set or some event/IRQ
@@ -47,4 +47,15 @@ Todo list:
 
 Changelog:
 
-	None thus far...
+	05-23-2019 by Lameguy64:
+	
+	* Got custom exit handler set using SetCustomExitFromException() (BIOS
+	  function B(19h)) working. Currently used to acknowledge VSync IRQ but
+	  actual VSync handling is still done with events and needs to be
+	  transferred to the custom exit handler. At least it lets BIOS
+	  controller functions to work now. See doc/dev notes.txt for details
+	  on how this handler behaves.
+	
+	* Made stack usage a lot less wasteful in ResetGraph() (you only need
+	  to allocate N words on stack based on N arguments of the function
+	  being called.
diff --git a/libpsn00b/psxgpu/resetgraph.s b/libpsn00b/psxgpu/resetgraph.s
index bc30d3b..189b1ad 100644
--- a/libpsn00b/psxgpu/resetgraph.s
+++ b/libpsn00b/psxgpu/resetgraph.s
@@ -9,9 +9,9 @@
 .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)
+	addiu	$sp, -8						# C style stack allocation (required if
+	sw		$ra, 0($sp)					# you call BIOS functions from asm)
+	sw		$a0, 4($sp)
 
 	la		$v0, _hooks_installed		# Skip installing hooks if this function
 	lbu		$v0, 0($v0)					# has already been called before once
@@ -20,8 +20,8 @@ ResetGraph:
 	nop
 
 	# Temporary, may help improve compatibility?
-	jal		SetDefaultExitFromException
-	nop
+	#jal		SetDefaultExitFromException
+	#nop
 
 	jal		ChangeClearPAD				# Remove pad handler left by the BIOS
 	move	$a0, $0
@@ -52,13 +52,16 @@ ResetGraph:
 
 	jal		OpenEvent					# Open a VSync event handler
 										# (PSXSDK style vsync handler)
-	nop
+	addiu	$sp, -16
+	addiu	$sp, 16
 
 	la		$v1, _vsync_event_desc		# Save event descriptor
 	sw		$v0, 0($v1)
 
-	jal		EnableEvent					# Enable the opened event
 	move	$a0, $v0
+	jal		EnableEvent					# Enable the opened event
+	addiu	$sp, -4
+	addiu	$sp, 4
 
 	la		$v0, _hooks_installed		# Set installed flag
 	li		$v1, 0x1
@@ -70,6 +73,11 @@ ResetGraph:
 	la		$v0, _vsync_callback_func	# Clear callback function
 	sw		$0 , 0($v0)
 
+	la		$a0, _custom_exit
+	jal		SetCustomExitFromException
+	addiu	$sp, -4
+	addiu	$sp, 4
+	
 	jal		ExitCriticalSection			# Re-enable interrupts
 	nop
 
@@ -87,7 +95,7 @@ ResetGraph:
 	sw		$v0, 0($v1)
 .not_pal:
 
-	lw		$a0, 24($sp)				# Get argument value
+	lw		$a0, 4($sp)				# Get argument value
 
 	lui		$a3, 0x1f80					# Set base I/O again (likely destroyed
 										# by previous calls)
@@ -118,10 +126,10 @@ ResetGraph:
 
 .init_done:
 
-	lw		$ra, 28($sp)
-	lw		$a0, 24($sp)				# Return
+	lw		$ra, 0($sp)
+	lw		$a0, 4($sp)					# Return
 	jr		$ra
-	addiu	$sp, 0x20
+	addiu	$sp, 8
 
 
 .global _vsync_func						# VSync event handler, executed on
@@ -142,8 +150,9 @@ _vsync_func:
 	andi	$v0, $v1, 0x1
 	beqz	$v0, .exit
 	nop
-	xori	$v1, $v1, 0x1				# Acknowledge the IRQ
-	sw		$v1, ISTAT($at)
+	
+	#xori	$v1, $v1, 0x1				# Acknowledge the IRQ
+	#sw		$v1, ISTAT($at)				# Commented out as it breaks BIOS pads
 
 	la		$v1, _vsync_counter			# Increment VSync counter
 	lw		$v0, 0($v1)
@@ -171,6 +180,32 @@ _vsync_func:
 	nop
 
 
+.global _vsync_func_2
+.type _vsync_func_2, @function
+_vsync_func_2:
+	
+	lui		$at, 0x1f80					# Check if there's a VSync IRQ
+	lw		$v0, IMASK($at)
+	nop
+	andi	$v0, $v0, 0x1
+	beqz	$v0, .exit_2
+	nop
+
+	lw		$v1, ISTAT($at)
+	nop
+	andi	$v0, $v1, 0x1
+	beqz	$v0, .exit_2
+	nop
+	
+	xori	$v1, $v1, 0x1				# Acknowledge the IRQ
+	sw		$v1, ISTAT($at)
+
+.exit_2:
+	
+	j		ReturnFromException
+	nop
+
+
 .global VSync							# VSync function
 .type VSync, @function
 VSync:
@@ -211,6 +246,26 @@ VSync:
 library_credits:
 	.string "psxgpu programs by Lameguy64"
 
+
+.type _custom_exit, @object
+_custom_exit:
+	.word _vsync_func_2		# pc
+	.word _vsync_stack		# sp
+	.word 0					# fp
+	.word 0					# s0
+	.word 0					# s1
+	.word 0					# s2
+	.word 0					# s3
+	.word 0					# s4
+	.word 0					# s5
+	.word 0					# s6
+	.word 0					# s7
+	.word _gp				# gp
+
+	.fill 60
+_vsync_stack:
+	.fill 4
+	
 .type _vsync_counter, @object
 _vsync_counter:
 	.word 0