more work towards floppy directory reading

src/dos_m65/,aliases_dos.s

@@ -135,7 +135,7 @@
 	; General purpose buffers, 512 bytes each, each starts at page start - XXX dynamic alllocation to be written
 
 	!addr SHARED_BUF_0     = $9200  ; XXX temporarily hardcoded for usage by SD card
-	!addr SHARED_BUF_1     = $9400
+	!addr SHARED_BUF_1     = $9400  ; XXX temporarily hardcoded for usage by floppy
 	!addr SHARED_BUF_2     = $9600
 	!addr SHARED_BUF_3     = $9800
 	!addr SHARED_BUF_4     = $9A00

src/dos_m65/dev_floppy/dev_fd_cmd_open.s

@@ -57,6 +57,10 @@ dev_fd_cmd_OPEN_dir:
 
 @lp1_end:
 
+	jmp fs_1581_read_dir_open
+
+
+
 	; XXX experimental code below
 
 	; Try to read track 40, sector 0 (disk header)

src/dos_m65/dev_floppy/dev_fd_util_readsector.s

@@ -2,26 +2,21 @@
 ; Read a single sector from a floppy drive
 
 
-; XXX utilize this
-
 dev_fd_util_readsector:
 
 	; Select FDD sector as buffer
 
 	lda #%10000000                     ; select floppy buffer
-	trb SD_BUFCTL
+	trb SD_BUFCTL    ; $D689
 
-	lda #%00000111
+	lda #%00001111                     ; set drive 0 (internal) and side 0
-	trb FDC_CONTROL                    ; set drive 0 (internal)    XXX support multiple drives
+	trb FDC_CONTROL  ; $D080
-
-	lda #%00001000
-	trb FDC_CONTROL                    ; set side 0 by default
 
 	; Select physical track and sector based on logical ones from PAR_TRACK and PAR_SECTOR
 
 	lda PAR_TRACK
 	dec
-	sta FDC_TRACK
+	sta FDC_TRACK    ; $D084
 
 	lda PAR_SECTOR
 	cmp #20
@@ -29,8 +24,8 @@ dev_fd_util_readsector:
 
 @side1:
 
-	lda #%00001000
+	lda #%00001000                     ; set side 1
-	tsb FDC_CONTROL                    ; set side 1
+	tsb FDC_CONTROL  ; $D080
 	
 	lda PAR_SECTOR
 	sec
@@ -42,21 +37,48 @@ dev_fd_util_readsector:
 @side0:
 
 	ldx #$00
-	stx FDC_SIDE
+	stx FDC_SIDE     ; $D086
 	clc
 	ror
-	sta FDC_SECTOR
+	sta FDC_SECTOR   ; $D085
 
-	; Ask the controller to read the sector
+	; Ask the controller to read the sector    XXX how to detect errors, missing disk, etc.?
 
 	lda #$40
-	sta FDC_COMMAND
+	sta FDC_COMMAND  ; $D081
-@lp:
+
-	lda FDC_STATUS_B                   ; XXX detect errors here   XXX waiting is probably not corrent
+	; Wait for RDREQ (indicates sector found)
-	bpl @lp
+
+@lp1:
+	lda FDC_STATUS_B ; $D083
+	bpl @lp1
+
+	; Wait for BUSY flag to clear
+
+@lp2:
+	lda FDC_STATUS_A ; $D082
+	bmi @lp2
+
+	; Wait for DRQ and EQ flags to go high
+
+@lp3:
+	lda FDC_STATUS_A ; $D082
+	and #%01100000
+	cmp #%01100000 ; XXX is this correct? .A seems to stay at $40 at this point
+	bne @lp3
 
 	; Copy sector to buffer in RAM
 
-	; XXX
+	lda #$00
+	sta DMAJOB_DST_MB
+	lda #<(SHARED_BUF_1 - $8000)
+	sta DMAJOB_DST_ADDR+0
+	lda #>(SHARED_BUF_1 - $8000)
+	sta DMAJOB_DST_ADDR+1
+	lda #$01
+	sta DMAJOB_DST_ADDR+2
 
+	jsr util_dma_launch_from_hwbuf    ; execute DMA job
+
+	clc
 	rts

src/dos_m65/dev_floppy/fs_1581_read_dir.s

@@ -0,0 +1,24 @@
+
+;
+; Hypervisor virtual filesystem - reading directory
+;
+
+
+fs_1581_read_dir_open:
+
+	; Try to read track 40, sector 0 (disk header)
+
+	lda #40
+	sta PAR_TRACK
+	lda #$00
+	sta PAR_SECTOR
+
+	jsr dev_fd_util_readsector         ; XXX handle read errors
+
+
+
+
+
+	; XXX continue implementation
+
+	jmp dos_EXIT_CLC

src/dos_m65/dev_floppy/fs_1581_read_file.s

@@ -0,0 +1,8 @@
+
+;
+; Hypervisor virtual filesystem - reading the file
+;
+
+
+fs_1581_read_file_open:
+

src/dos_m65/dev_sdcard/fs_hvsr_read_file.s

@@ -1,6 +1,6 @@
 
 ;
-; Hypervisor virtual filesystem - opening the file
+; Hypervisor virtual filesystem - reading the file
 ;