Release candidate 4

gsram_asm.s

@@ -0,0 +1,98 @@
+.setcpu		"65816"
+.autoimport on
+.importzp	sp
+
+.export 	_gsram_getsize
+
+.macro A8
+       sep #$20 ; put the 65C816 in 8-bit accumulator mode
+      .A8
+.endmacro
+
+.macro I8
+       sep #$10 ; put the 65C816 in 8-bit index register mode
+      .I8
+.endmacro
+
+.macro AI8
+       sep #$30 ; put the 65C816 in 8-bit accumulator and index register mode
+      .A8
+      .I8
+.endmacro
+
+.macro A16
+       rep #$20 ; put the 65C816 in 8-bit accumulator mode
+      .A16
+.endmacro
+
+.macro I16
+       rep #$10 ; put the 65C816 in 8-bit index register mode
+      .I16
+.endmacro
+
+.macro AI16
+       rep #$30 ; put the 65C816 in 8-bit accumulator and index register mode
+      .A16
+      .I16
+.endmacro
+
+.segment	"CODE"
+
+.proc _gsram_getsize: near
+.A8
+.I8
+	; Preamble
+	php				; Push status
+	sei				; Disable interrupts
+	clc				; Clear carry
+	xce				; Clear emulation bit
+	php				; Push status
+	phb				; Push bank
+	AI8
+
+	; Store bank number at address 0xFFFF in each bank
+	ldy #$7F		; Start at bank 0x7F
+	BankSetLoop:
+	phy				; Push future bank
+	plb 			; Pull bank
+	lda $8000		; Get address 0xFFFF in this bank
+	pha				; Save old address 0xFFFF contents
+	tya				; A = Y
+	eor #$FF		; Flip all bits
+	tay				; Y = A
+	sty $8000		; Overwrite address 0xFFFF with bank number
+	eor #$FF		; Flip all bits back
+	tay				; Y = A
+	dey				; Decrement bank number
+	cpy #$FF		; Have we wrapped around?
+	bne BankSetLoop ; If not, repeat
+
+	; Count banks with matching bank number
+	ldy #$00		; Y is bank
+	ldx #$00		; X is count
+	CountLoop:
+	phy				; Push future bank
+	plb				; Pull bank
+	tya				; A = Y
+	eor #$FF		; Flip all bits
+	tay				; Y = A
+	cpy $8000		; Is bank num stored at address 0xFFFF?
+	bne AfterInc	; If not, skip increment
+	inx				; If so, increment bank count
+	AfterInc:
+	eor #$FF		; Flip all bits back
+	tay				; Y = A
+	pla				; Get contents to restore
+	sta $8000		; Restore address 0xFFFF in this bank
+	iny				; Move to next bank
+	cpy #$80		; Are we at bank 0x80 yet?
+	bne CountLoop	; If not, repeat
+
+	; Postamble
+	plb				; Restore bank
+	plp				; Restore status
+	xce				; Restore emulation bit
+	txa				; Transfer bank count to A
+	plp				; Pull status again to pull I flag
+	rts
+.endproc

ram2gs_asm.s

@@ -40,72 +40,15 @@
 
 .segment	"CODE"
 
-.proc _gsram_getsize: near
-.A8
-.I8
-	; Preamble
-	sei				; Disable interrupts
-	clc				; Clear carry
-	xce				; Clear emulation bit
-	php				; Push status
-	phb				; Push bank
-	AI8
-
-	; Store bank number at address 0xFFFF in each bank
-	ldy #$7F		; Start at bank 0x7F
-	BankSetLoop:
-	phy				; Push future bank
-	plb 			; Pull bank
-	lda $8000		; Get address 0xFFFF in this bank
-	pha				; Save old address 0xFFFF contents
-	tya				; A = Y
-	eor #$FF		; Flip all bits
-	tay				; Y = A
-	sty $8000		; Overwrite address 0xFFFF with bank number
-	eor #$FF		; Flip all bits back
-	tay				; Y = A
-	dey				; Decrement bank number
-	cpy #$FF		; Have we wrapped around?
-	bne BankSetLoop ; If not, repeat
-
-	; Count banks with matching bank number
-	ldy #$00		; Y is bank
-	ldx #$00		; X is count
-	CountLoop:
-	phy				; Push future bank
-	plb				; Pull bank
-	tya				; A = Y
-	eor #$FF		; Flip all bits
-	tay				; Y = A
-	cpy $8000		; Is bank num stored at address 0xFFFF?
-	bne AfterInc	; If not, skip increment
-	inx				; If so, increment bank count
-	AfterInc:
-	eor #$FF		; Flip all bits back
-	tay				; Y = A
-	pla				; Get contents to restore
-	sta $8000		; Restore address 0xFFFF in this bank
-	iny				; Move to next bank
-	cpy #$80		; Are we at bank 0x80 yet?
-	bne CountLoop	; If not, repeat
-
-	; Postamble
-	plb				; Restore bank
-	plp				; Restore status
-	xce				; Restore emulation bit
-	cli				; Enable interrupts
-	txa				; Transfer bank count to A
-	rts
-.endproc
-
 .proc _ram2gs_getsize: near
 .A8
 .I8
 	; Preamble
+	php				; Push status
 	sei				; Disable interrupts
 	clc				; Clear carry
 	xce				; Clear emulation bit
-	php				; Push status
+	php				; Push status again, reflecting emulation bit
 	phb				; Push bank
 	AI8
 
@@ -152,8 +95,8 @@
 	plb				; Restore bank
 	plp				; Restore status
 	xce				; Restore emulation bit
-	cli				; Enable interrupts
 	txa				; Transfer bank count to A
+	plp				; Pull status again to pull I flag
 	rts
 .endproc
 
@@ -210,10 +153,11 @@
 .A8
 .I8
 	; Preamble
+	php				; Push status
 	sei				; Disable interrupts
 	clc				; Clear carry
 	xce				; Clear emulation bit
-	php				; Push status
+	php				; Push status again, reflecting emulation bit
 	phb				; Push bank
 	AI8
 
@@ -278,16 +222,22 @@
 	plb				; Restore bank
 	plp				; Restore status
 	xce				; Restore emulation bit
-	cli				; Enable interrupts
+	plp				; Pull status again to pull I flag
 	rts
 .endproc
 
 .proc _ram2gs_cmd: near
 .A8
 .I8
-	; Save current bank and command in accumulator
+	; Preamble
-	phb
+	php				; Push status
-	pha
+	sei				; Disable interrupts
+	clc				; Clear carry
+	xce				; Clear emulation bit
+	php				; Push status again, reflecting emulation bit
+	phb				; Push bank
+	pha				; Push command in accumulator
+	AI8
 	; Switch to bank 0xFB
 	lda #$FB
 	pha
@@ -300,7 +250,10 @@
 	; Pull and submit command 
 	pla
 	sta $FFFD
-	; Restore bank and return
+	; Postamble
-	plb
+	plb				; Restore bank
+	plp				; Restore status
+	xce				; Restore emulation bit
+	plp				; Pull status again to pull I flag
 	rts
 .endproc