MEGA65 glue code for DOS finished

src/,,config_mega65.s

@@ -130,6 +130,13 @@
 // #define CONFIG_SHOW_FEATURES
 
 
+// Built-in DOS configuration
+
+.const CONFIG_UNIT_SDCARD  = 0 // do not change, DOS is not implemented yet
+.const CONFIG_UNIT_FLOPPY  = 0 // do not change, DOS is not implemented yet
+.const CONFIG_UNIT_RAMDISK = 0 // do not change, DOS is not implemented yet
+
+
 // Debug options
 
 // #define CONFIG_DBG_STUBS_BRK

src/dos_m65/,aliases_dos.s

@@ -0,0 +1,11 @@
+//
+// Memory locations for the DOS
+//
+
+	//
+	// Page 0
+	//
+
+	.label UNIT_SDCARD  = $00
+	.label UNIT_FLOPPY  = $01
+	.label UNIT_RAMDISK = $02

src/dos_m65/4000.dos_vectable.s

@@ -3,6 +3,7 @@
 
 .word dos_INIT
 .word dos_CHKUNIT
+.word dos_SETUNIT
 .word dos_ACPTR
 .word dos_CIOUT
 .word dos_LISTEN

src/dos_m65/dos_chkunit.s

@@ -0,0 +1,38 @@
+
+//
+// Unit number handling. For detailed description see 'm65dos_bridge.s' file
+//
+
+
+dos_CHKUNIT:
+
+	cmp UNIT_SDCARD
+	beq dos_CHKUNIT_sdcard
+	cmp UNIT_FLOPPY
+	beq dos_CHKUNIT_floppy
+	cmp UNIT_RAMDISK
+	beq dos_CHKUNIT_ramdisk
+
+	sec
+	rts
+
+dos_CHKUNIT_sdcard:
+
+	lda #$00
+	skip_2_bytes_trash_nvz
+
+	// FALLTROUGH
+
+dos_CHKUNIT_floppy:
+
+	lda #$01
+	skip_2_bytes_trash_nvz
+
+	// FALLTROUGH
+
+dos_CHKUNIT_ramdisk:
+
+	lda #$02
+	
+	clc
+	rts

src/dos_m65/dos_init.s

@@ -0,0 +1,17 @@
+
+//
+// Initializes DOS. For detailed description see 'm65dos_bridge.s' file
+//
+
+dos_INIT:
+
+	lda #CONFIG_UNIT_SDCARD
+	sta UNIT_SDCARD
+	lda #CONFIG_UNIT_FLOPPY
+	sta UNIT_FLOPPY
+	lda #CONFIG_UNIT_RAMDISK
+	sta UNIT_RAMDISK
+
+	// XXX initialize drivers, etc.
+
+	rts

src/dos_m65/dos_setunit.s

@@ -0,0 +1,42 @@
+
+//
+// Unit number handling. For detailed description see 'm65dos_bridge.s' file
+//
+
+
+dos_SETUNIT:
+
+	// XXX check if .X is valid
+
+	cmp #$00
+	beq dos_SETUNIT_sdcard
+	cmp #$01
+	beq dos_SETUNIT_floppy
+	cmp #$02
+	beq dos_SETUNIT_ramdisk
+
+	sec
+	rts
+
+dos_SETUNIT_sdcard:
+
+	stx UNIT_SDCARD
+	skip_2_bytes_trash_nvz
+
+	// FALLTROUGH
+
+dos_SETUNIT_floppy:
+
+	stx UNIT_FLOPPY
+	skip_2_bytes_trash_nvz
+
+	// FALLTROUGH
+
+dos_SETUNIT_ramdisk:
+
+	stx UNIT_RAMDISK
+
+	// FALLTROUGH
+
+	clc
+	rts

src/dos_m65/stubs.s

@@ -1,10 +1,6 @@
 
 // Dummy implementations - XXX to be replaced with real ones
 
-dos_INIT:
-	nop
-dos_CHKUNIT:
-	nop
 dos_ACPTR:
 	nop
 dos_CIOUT:

src/kernal/iec/acptr.s

@@ -22,6 +22,11 @@ ACPTR:
 	rts
 !:
 
+#if ROM_LAYOUT_M65
+	jsr m65dos_check
+	bcc_16 m65dos_acptr                // branch if device is handeld by internal DOS
+#endif
+
 #if CONFIG_IEC
 #if CONFIG_IEC_JIFFYDOS
 	jmp iec_rx_dispatch

src/kernal/iec/ciout.s

@@ -35,6 +35,11 @@ ciout_store_in_buffer:
 	
 ciout_send_byte:
 
+#if ROM_LAYOUT_M65
+	jsr m65dos_check
+	bcc_16 m65dos_ciout                // branch if device is handeld by internal DOS
+#endif
+
 	clc                                // send without EOI
 #if CONFIG_IEC_JIFFYDOS
 	jsr iec_tx_dispatch

src/kernal/iec/iec_cmd_close.s

@@ -20,6 +20,13 @@ iec_cmd_close:
 !:
 	ora #$E0
 
+#if ROM_LAYOUT_M65
+
+	jsr m65dos_check
+	bcc_16 m65dos_second                 // branch if device is handeld by internal DOS
+
+#endif
+
 	jmp common_open_close_unlsn_second
 
 

src/kernal/iec/iec_cmd_open.s

@@ -20,6 +20,13 @@ iec_cmd_open: // similar to TKSA, but without turnaround
 !:
 	ora #$F0
 
+#if ROM_LAYOUT_M65
+
+	jsr m65dos_check
+	bcc_16 m65dos_second                 // branch if device is handeld by internal DOS
+
+#endif
+
 #if CONFIG_IEC_BURST_CIA1 || CONFIG_IEC_BURST_CIA2 || CONFIG_IEC_BURST_MEGA_65
 	pha
 	jsr burst_advertise

src/kernal/iec/listen.s

@@ -16,11 +16,22 @@
 
 LISTEN:
 
-#if CONFIG_IEC
+#if CONFIG_IEC || ROM_LAYOUT_M65
 
 	// According to serial-bus.pdf (page 15) this routine flushes the IEC out buffer
 	jsr iec_tx_flush
 
+#endif
+
+#if ROM_LAYOUT_M65
+
+	jsr m65dos_detect
+	bcc_16 m65dos_listen                 // branch if device is handeld by internal DOS
+
+#endif
+
+#if CONFIG_IEC
+
 	// Check whether device number is correct
 	jsr iec_check_devnum_oc
 	bcc !+

src/kernal/iec/second.s

@@ -13,8 +13,18 @@
 //
 
 
+// XXX cleanup: iec_cmd_open and iec_cmd_close should just do ORA and jump directly here
+
+
 SECOND:
 
+#if ROM_LAYOUT_M65
+
+	jsr m65dos_check
+	bcc_16 m65dos_second                 // branch if device is handeld by internal DOS
+
+#endif
+
 #if CONFIG_IEC
 
 	// Due to OPEN/CLOSE/TKSA/SECOND command encoding, allowed channels are 0-15; it is the caller
@@ -22,8 +32,6 @@ SECOND:
 	// - https://www.lemon64.com/forum/viewtopic.php?t=57694&sid=531ba3592bcffadef2ac8b9162f2e529
 	// - https://www.pagetable.com/?p=1031 (Kernal API description)
 
-	// XXX consider checking whether value is in range (contrary to original ROM implementation)
-
 	jmp common_open_close_unlsn_second
 
 #else

src/kernal/iec/talk.s

@@ -16,11 +16,22 @@
 
 TALK:
 
-#if CONFIG_IEC
+#if CONFIG_IEC || ROM_LAYOUT_M65
 
 	// According to serial-bus.pdf (page 15) this routine flushes the IEC out buffer
 	jsr iec_tx_flush
 
+#endif
+
+#if ROM_LAYOUT_M65
+
+	jsr m65dos_detect
+	bcc_16 m65dos_talk                 // branch if device is handeld by internal DOS
+
+#endif
+
+#if CONFIG_IEC
+
 	// Check whether device number is correct
 	jsr iec_check_devnum_oc
 	bcc !+

src/kernal/iec/tksa.s

@@ -15,6 +15,13 @@
 
 TKSA:
 
+#if ROM_LAYOUT_M65
+
+	jsr m65dos_check
+	bcc_16 m65dos_tksa                   // branch if device is handeld by internal DOS
+
+#endif
+
 #if CONFIG_IEC
 
 	// Due to OPEN/CLOSE/TKSA/SECOND command encoding, allowed channels are 0-15; it is the caller

src/kernal/iec/unlsn.s

@@ -16,11 +16,22 @@
 
 UNLSN:
 
-#if CONFIG_IEC
+#if CONFIG_IEC || ROM_LAYOUT_M65
 
 	// According to serial-bus.pdf (page 15) this routine flushes the IEC out buffer
 	jsr iec_tx_flush
 
+#endif
+
+#if ROM_LAYOUT_M65
+
+	jsr m65dos_check
+	bcc_16 m65dos_unlsn                // branch if device is handeld by internal DOS
+
+#endif
+
+#if CONFIG_IEC
+
 #if CONFIG_IEC_JIFFYDOS || CONFIG_IEC_DOLPHINDOS
 
 	lda #$FF                           // do not use JiffyDOS / DolphinDOS anymore, trigger JiffyDOS detection

src/kernal/iec/untlk.s

@@ -16,11 +16,22 @@
 
 UNTLK:
 
-#if CONFIG_IEC
+#if CONFIG_IEC || ROM_LAYOUT_M65
 
 	// According to serial-bus.pdf (page 15) this routine flushes the IEC out buffer
 	jsr iec_tx_flush
 
+#endif
+
+#if ROM_LAYOUT_M65
+
+	jsr m65dos_check
+	bcc_16 m65dos_untlk                // branch if device is handeld by internal DOS
+
+#endif
+
+#if CONFIG_IEC
+
 #if CONFIG_IEC_JIFFYDOS || CONFIG_IEC_DOLPHINDOS
 
 	lda #$FF                           // do not use JiffyDOS / DolphinDOS anymore, trigger JiffyDOS detection

src/kernal/iec_fast/m65dos_bridge.s

@@ -8,44 +8,58 @@
 
 .label VDOS_INIT    = $4000 +  0 * 2
 .label VDOS_CHKUNIT = $4000 +  1 * 2
-.label VDOS_ACPTR   = $4000 +  2 * 2
-.label VDOS_CIOUT   = $4000 +  3 * 2
-.label VDOS_LISTEN  = $4000 +  4 * 2
-.label VDOS_SECOND  = $4000 +  5 * 2
-.label VDOS_TALK    = $4000 +  6 * 2
-.label VDOS_TKSA    = $4000 +  7 * 2
-.label VDOS_UNTLK   = $4000 +  8 * 2
-.label VDOS_UNLSN   = $4000 +  9 * 2
-
-
-// XXX connect this to core IEC implementation
+.label VDOS_SETUNIT = $4000 +  2 * 2
+.label VDOS_ACPTR   = $4000 +  3 * 2
+.label VDOS_CIOUT   = $4000 +  4 * 2
+.label VDOS_LISTEN  = $4000 +  5 * 2
+.label VDOS_SECOND  = $4000 +  6 * 2
+.label VDOS_TALK    = $4000 +  7 * 2
+.label VDOS_TKSA    = $4000 +  8 * 2
+.label VDOS_UNTLK   = $4000 +  9 * 2
+.label VDOS_UNLSN   = $4000 + 10 * 2
 
 
 m65dos_init:
 
+	// Initializes the DOS internal variables
+
 	jsr map_DOS_1
 	jsr_ind VDOS_INIT
 	jmp_8 !+
 
-m65dos_chkunit:
+m65dos_chkunit:                        // XXX expose to BASIC
+
+	// Checks is the unit number is supported by the internal DOS
+	// Input:  .A - unit number to check
+	// Output: Carry set if not supported, otherwise .A contains unit type (0 = SD card, 1 = internal floppy, 2 = RAM disk)
 
 	jsr map_DOS_1
 	jsr_ind VDOS_CHKUNIT
 	jmp_8 !+
 
+m65dos_setunit:                        // XXX expose to BASIC
+
+	// Set the unit number
+	// Input:  .A - unit number, .X - unit type (as in m65dos_chkunit)
+	// Output: Carry set means error
+
+	jsr map_DOS_1
+	jsr_ind VDOS_SETUNIT
+	jmp_8 !+
+
 m65dos_acptr:
 
 	jsr map_DOS_1
 	jsr_ind VDOS_ACPTR
 !:
-	jmp map_NORMAL_from_DOS_1          // try to make ACPTR slightly faster
+	jmp map_NORMAL_from_DOS_1          // ACPTR is slightly faster
 
 m65dos_ciout:
 
 	jsr map_DOS_1
 	jsr_ind VDOS_CIOUT
 !:
-	jmp map_NORMAL_from_DOS_1          // try to make CIOUT slightly faster
+	jmp map_NORMAL_from_DOS_1          // CIOUT is slightly faster
 
 m65dos_listen:
 

src/kernal/iec_fast/m65dos_check.s

@@ -0,0 +1,22 @@
+// #LAYOUT# M65 KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+//
+// MEGA65 pseudo-IEC internal DOS support - check if the current device is already handled by internal DOS
+//
+
+
+m65dos_check:
+
+	pha
+	lda IECPROTO
+	cmp #IEC_ROMDOS
+	beq !+
+
+	pla
+	sec
+	rts
+!:
+	pla
+	clc
+	rts

src/kernal/iec_fast/m65dos_detect.s

@@ -0,0 +1,22 @@
+// #LAYOUT# M65 KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+//
+// MEGA65 pseudo-IEC internal DOS support - detect if a drive should be handled by internal DOS
+//
+
+
+m65dos_detect:
+
+	// Checks if drive is supported by internal DOS
+	// Output: Carry set if not supported, if supported IECPROTO isset to IEC_ROMDOS
+
+	pha
+	jsr m65dos_chkunit
+	bcs !+
+
+	lda #IEC_ROMDOS
+	sta IECPROTO
+!:
+	pla
+	rts