more work towards making LOAD command accept filename

c64/basic/cmd_load.s

@@ -17,6 +17,17 @@ cmd_load:
 	lda #$00 		; LOAD not verify
 	ldx #<$0801		; LOAD address = $0801
 	ldy #>$0801
+
+	;; Set filename and length
+	lda #$24
+	sta $0400
+	lda #$01
+	sta current_filename_length
+	lda #<$0400
+	sta current_filename_ptr+0
+	lda #>$0401
+	sta current_filename_ptr+1
+	
 	jsr $ffd5
 	bcc +
 

c64/basic/under_rom_routines.s

@@ -23,9 +23,45 @@ install_ram_routines:
 
 ram_routines_start:	
 
+	;; XXX - Routine order must match that of the KERNAL version of the file.
+	;; (since it has fewer routines)
 tiny_nmi_handler_routine:
 	inc missed_nmi_flag
 	rti
+peek_under_roms_routine:
+	php
+	; Offset of arg of lda ($00),y	
+	stx peek_under_roms+pa-peek_under_roms_routine+1
+	jsr memmap_allram
+pa:	lda ($00),y
+	jsr memmap_normal
+	plp
+	rts
+
+poke_under_roms_routine:
+	php
+	; Offset of arg of lda ($00),y	
+	stx poke_under_roms+pb-poke_under_roms_routine+1
+	jsr memmap_allram
+pb:	sta ($00),y
+	jsr memmap_normal_routine
+	plp
+	rts
+
+memmap_normal_routine:
+	pha
+	lda #$37
+	sta $01
+	pla
+	rts
+
+memmap_allram_routine:
+	sei
+	pha
+	lda #$04
+	sta $01
+	pla
+	rts
 
 shift_mem_up_routine:
 	;; Move memmove_size bytes from memmove_src to memmove_dst,
@@ -68,33 +104,6 @@ smd1:
 	jmp memmap_normal
 
 	
-peek_under_roms_routine:
-	stx peek_under_roms+7 	;Offset of arg of lda ($00),y
-	jsr memmap_allram
-	lda ($00),y
-	jmp memmap_normal
-
-poke_under_roms_routine:
-	stx poke_under_roms+7 	;Offset of arg of lda ($00),y
-	jsr memmap_allram
-	sta ($00),y
-	;; FALL THROUGH
-memmap_normal_routine:
-	pha
-	lda #$37
-	sta $01
-	pla
-	cli
-	rts
-
-memmap_allram_routine:
-	sei
-	pha
-	lda #$04
-	sta $01
-	pla
-	rts
-
 ram_routines_end:
 	.alias ram_routines_len ram_routines_end-ram_routines_start
 	

c64/kernal/,aliases.s

@@ -75,3 +75,14 @@
 	.alias enable_case_switch $0291
 	.alias screen_scroll_disable $0292
 	.alias pal_or_ntsc $02A6
+
+	;; Under-ROM routines
+	;; (BASIC also includes them. XXX - We should de-duplicate them in a safe manner)
+	.alias missed_nmi_flag         $2A7
+	.alias tiny_nmi_handler		$2A8	
+	.alias peek_under_roms tiny_nmi_handler+peek_under_roms_routine-tiny_nmi_handler_routine
+	.alias poke_under_roms tiny_nmi_handler+poke_under_roms_routine-tiny_nmi_handler_routine
+	.alias memmap_allram tiny_nmi_handler+memmap_allram_routine-tiny_nmi_handler_routine
+	.alias memmap_normal tiny_nmi_handler+memmap_normal_routine-tiny_nmi_handler_routine
+	
+	

c64/kernal/load.s

@@ -22,6 +22,9 @@ load:
 	;; Store start address of LOAD
 	stx load_save_start_ptr+0
 	sty load_save_start_ptr+1
+
+	;; We need our helpers to get to filenames under ROMs or IO area
+	jsr install_ram_routines
 	
 	;; Disable IRQs, since timing matters!
 	SEI
@@ -62,9 +65,28 @@ load:
 	jsr iec_release_atn
 
 	;; Send filename (p16)
-	lda #$24 		; $ = directory
+	ldy #0
+
+send_filename:
+	cpy current_filename_length
+	beq sent_filename
+	
+	ldx #<current_filename_ptr
+	jsr peek_under_roms
+
+	;; Save Y because iec_tx_byte will corrupt it
+	tax
+	tya
+	pha
+	txa
+	
 	jsr iec_tx_byte
 
+	pla
+	tay
+	jmp send_filename
+
+sent_filename:	
 	;; Command device to unlisten to indicate end of file name. (p16)
 	jsr iec_assert_atn
 	lda #$3f

c64/kernal/under_rom_routines.s

@@ -0,0 +1,66 @@
+	;; IMPORTANT:
+	;; These routines lengths cannot be changed without changing
+	;; the aliases for peek_under_roms, poke_under_roms etc
+	;; in ,aliases.s.
+	;; Thus those addresses are expressed using formulae.
+
+install_ram_routines:
+	;; Copy routines into place
+	ldx #ram_routines_len-1
+*
+	lda ram_routines_start,x
+	sta tiny_nmi_handler,x
+	dex
+	bpl -
+
+	;; Point NMI handler to tiny_nmi_handler
+	lda #<tiny_nmi_handler
+	sta $FFFE
+	lda #>tiny_nmi_handler
+	sta $FFFF
+
+	rts
+
+ram_routines_start:	
+
+tiny_nmi_handler_routine:
+	inc missed_nmi_flag
+	rti
+peek_under_roms_routine:
+	php
+	; Offset of arg of lda ($00),y	
+	stx peek_under_roms+pa-peek_under_roms_routine+1
+	jsr memmap_allram
+pa:	lda ($00),y
+	jsr memmap_normal
+	plp
+	rts
+
+poke_under_roms_routine:
+	php
+	; Offset of arg of lda ($00),y	
+	stx poke_under_roms+pb-poke_under_roms_routine+1
+	jsr memmap_allram
+pb:	sta ($00),y
+	jsr memmap_normal_routine
+	plp
+	rts
+
+memmap_normal_routine:
+	pha
+	lda #$37
+	sta $01
+	pla
+	rts
+
+memmap_allram_routine:
+	sei
+	pha
+	lda #$04
+	sta $01
+	pla
+	rts
+	
+ram_routines_end:
+	.alias ram_routines_len ram_routines_end-ram_routines_start
+