Add ramdisk as disk 5, and a ryfs_format routine

RYFS.asm

@@ -8,6 +8,12 @@ check_disk:
     ifnz jmp check_disk_fail
     cmp r0, 4
     ifz jmp check_disk_continue
+    cmp r0, 5
+    ifnz jmp check_disk_1
+    ifz call is_ramdisk_formatted
+    ifnz jmp check_disk_fail
+    cmp r0, 5
+    ifz jmp check_disk_continue
 check_disk_1:
     or r0, 0x80001000
     in r0, r0

RYFS.okm

@@ -17,6 +17,7 @@ MODULE RYFS;
     EXTERN PROCEDURE read_sector: INT;
     EXTERN PROCEDURE write_sector: INT;
     EXTERN PROCEDURE copy_memory_bytes: INT;
+    EXTERN PROCEDURE copy_string: INT;
     EXTERN PROCEDURE compare_memory_bytes_wrapper: INT;
     EXTERN PROCEDURE brk: INT;
 
@@ -178,6 +179,61 @@ MODULE RYFS;
         END;
     END;
 
+    PROCEDURE ryfs_format(diskId: INT; diskSizeInSectors: INT;);
+    VAR i: INT;
+        bitmapSectors: CHAR;
+    BEGIN
+        (* clear the sector data *)
+        i := 0;
+        WHILE i <| 512 DO
+            PUTCHAR(PTROF(TEMP_SECTOR_BUF) + i, 0);
+            i := i + 1;
+        END;
+
+        (* write the number of bitmap sectors *)
+        bitmapSectors := ryfs_ceil(diskSizeInSectors, 4096) /| 4096;
+        PUTCHAR(PTROF(TEMP_SECTOR_BUF), bitmapSectors);
+
+        (* write version number and magic bytes *)
+        PUTCHAR(PTROF(TEMP_SECTOR_BUF) + 1, 1);
+        PUTCHAR(PTROF(TEMP_SECTOR_BUF) + 2, 82);
+        PUTCHAR(PTROF(TEMP_SECTOR_BUF) + 3, 89);
+
+        (* write disk size *)
+        PUTSHORT(PTROF(TEMP_SECTOR_BUF) + 4, diskSizeInSectors);
+
+        (* write directory label *)
+        copy_string("ramdisk", PTROF(TEMP_SECTOR_BUF) + 6);
+
+        (* write the directory sector out to disk *)
+        write_sector(1, diskId, PTROF(TEMP_SECTOR_BUF));
+
+        (* clear the sector data *)
+        i := 0;
+        WHILE i <| 512 DO
+            PUTCHAR(PTROF(TEMP_SECTOR_BUF) + i, 0);
+            i := i + 1;
+        END;
+
+        (* zero the bitmap sectors *)
+        i := 0;
+        WHILE i <| bitmapSectors DO
+            write_sector(i + 2, diskId, PTROF(TEMP_SECTOR_BUF));
+            i := i + 1;
+        END;
+
+        (* mark the boot sector and directory sector as used *)
+        ryfs_mark_used(0, diskId);
+        ryfs_mark_used(1, diskId);
+
+        (* mark the bitmap sectors as used *)
+        i := 0;
+        WHILE i <| bitmapSectors DO
+            ryfs_mark_used(i + 2, diskId);
+            i := i + 1;
+        END;
+    END;
+
     PROCEDURE ryfs_seek(offset: INT; struct: POINTER TO ROMFile;);
     BEGIN
         struct^.seekOffset := offset;

disk.asm

@@ -1,6 +1,7 @@
 ; disk routines
 
 const TEMP_SECTOR_BUF: 0x01FFF808
+const RAMDISK_START: 0x03800000
 
 ; read a sector into the specified memory buffer
 ; inputs:
@@ -12,6 +13,8 @@ const TEMP_SECTOR_BUF: 0x01FFF808
 read_sector:
     cmp.8 r1, 4
     ifz jmp read_romdisk_sector
+    cmp.8 r1, 5
+    ifz jmp read_ramdisk_sector
 
     push r3
     push r4
@@ -54,6 +57,34 @@ read_romdisk_sector:
     pop r0
     ret
 
+; read a sector from the ramdisk into the specified memory buffer
+; inputs:
+; r0: sector number
+; r2: sector buffer (512 bytes)
+; outputs:
+; none
+read_ramdisk_sector:
+    push r0
+    push r1
+    push r2
+
+    ; source pointer
+    mul r0, 512
+    add r0, RAMDISK_START
+
+    ; destination pointer
+    mov r1, r2
+
+    ; copy 512 bytes
+    mov r2, 512
+
+    call copy_memory_bytes
+
+    pop r2
+    pop r1
+    pop r0
+    ret
+
 ; check if a RYFS image is included as a romdisk
 ; inputs:
 ; none
@@ -69,6 +100,21 @@ is_romdisk_available:
     pop r0
     ret
 
+; check if a RYFS filesystem is initialized on the ramdisk
+; inputs:
+; none
+; outputs:
+; Z flag: set if available, reset if not
+is_ramdisk_formatted:
+    push r0
+
+    mov r0, RAMDISK_START
+    add r0, 514
+    cmp.16 [r0], 0x5952
+
+    pop r0
+    ret
+
 ; write a sector from the specified memory buffer
 ; inputs:
 ; r0: sector number
@@ -79,6 +125,8 @@ is_romdisk_available:
 write_sector:
     cmp.8 r1, 4
     ifz ret
+    cmp.8 r1, 5
+    ifz jmp write_ramdisk_sector
 
     push r3
     push r4
@@ -92,3 +140,32 @@ write_sector:
     pop r4
     pop r3
     ret
+
+; write a sector to ramdisk from the specified memory buffer
+; inputs:
+; r0: sector number
+; r2: sector buffer (512 bytes)
+; outputs:
+; none
+write_ramdisk_sector:
+    push r0
+    push r1
+    push r2
+
+    ; destination pointer
+    mov r1, r0
+    mul r1, 512
+    add r1, RAMDISK_START
+
+    ; source pointer
+    mov r0, r2
+
+    ; copy 512 bytes
+    mov r2, 512
+
+    call copy_memory_bytes
+
+    pop r2
+    pop r1
+    pop r0
+    ret

fox32rom.def

@@ -83,6 +83,8 @@ ryfs_write:                               jmp [0xF0045024]
 is_romdisk_available:                     jmp [0xF0045028]
 ryfs_create:                              jmp [0xF004502C]
 ryfs_delete:                              jmp [0xF0045030]
+ryfs_format:                              jmp [0xF0045034]
+is_ramdisk_formatted:                     jmp [0xF0045038]
 
 ; memory copy/compare jump table
 copy_memory_bytes:                        jmp [0xF0046000]

main.asm

@@ -130,6 +130,11 @@ draw_bottom_bar_loop:
     call change_icon
     call setup_icon
 
+    call is_ramdisk_formatted
+    ifnz mov r0, 5
+    ifnz mov r1, 0x00800000
+    ifnz call ryfs_format
+
 event_loop:
     call get_next_event
 
@@ -293,6 +298,8 @@ disk_icon_q:
     data.32 is_romdisk_available
     data.32 ryfs_create
     data.32 ryfs_delete
+    data.32 ryfs_format
+    data.32 is_ramdisk_formatted
 
     ; memory copy/compare jump table
     org.pad 0xF0046000