Add some basic fat32 code

2023-12-03 23:27:45 -08:00
parent 184c58b962
commit 5c74d161d4
11 changed files with 326 additions and 7 deletions
--- a/sw/kernel/filesystems/fat32.s
+++ b/sw/kernel/filesystems/fat32.s
@@ -0,0 +1,115 @@
+.MACPACK generic
+
+.autoimport
+.feature string_escapes
+
+.importzp ptr1, sreg
+
+.import _SD_readSingleBlock
+
+.export _fat32_init
+
+
+.data
+fat_start_sector: .res 2
+data_start_sector: .res 2
+sd_buf: .res 512
+
+bps_val_str: .asciiz "Bytes Per Sector: 0x%x\n"
+sps_val_str: .asciiz "Sectors Per Cluster: 0x%x\n"
+rsv_val_str: .asciiz "Reserved Sectors: 0x%x\n"
+fat_count_str: .asciiz "FAT count: 0x%x\n"
+fat_sect_str: .asciiz "Sectors per FAT: 0x%x\n"
+fat_size_tot_str: .asciiz "Total fat size: 0x%lx\n"
+rsv_sect_bytes_str: .asciiz "Total reserved bytes: 0x%x\n"
+rsv_sd_sectors: .asciiz "Reserved SD Sectors: 0x%x\n"
+
+.code
+
+bytes_per_sector        = sd_buf + $0B
+sectors_per_cluster     = sd_buf + $0D
+reserved_sectors        = sd_buf + $0E
+fat_count               = sd_buf + $10
+sectors_per_fat         = sd_buf + $24
+
+.proc _fat32_init
+    ; load sector 0 into sd_buf
+    lda #$00
+    ldx #$00
+    stz sreg
+    stz sreg+1
+    jsr pusheax
+    lda #<sd_buf
+    ldx #>sd_buf
+    jsr pushax
+    lda #<ptr1
+    ldx #>ptr1
+    jsr _SD_readSingleBlock
+
+    lda #<bps_val_str
+    ldx #>bps_val_str
+    jsr pushax
+    lda bytes_per_sector
+    ldx bytes_per_sector+1
+    jsr pushax
+    ldy #$4
+    jsr _printf
+
+    lda #<sps_val_str
+    ldx #>sps_val_str
+    jsr pushax
+    lda sectors_per_cluster
+    ldx #$00
+    jsr pushax
+    ldy #$4
+    jsr _cprintf
+
+    lda #<rsv_val_str
+    ldx #>rsv_val_str
+    jsr pushax
+    lda reserved_sectors
+    ldx #$00
+    jsr pushax
+    ldy #$4
+    jsr _cprintf
+
+    lda #<fat_count_str
+    ldx #>fat_count_str
+    jsr pushax
+    lda fat_count
+    ldx #$00
+    jsr pushax
+    ldy #$4
+    jsr _cprintf
+
+
+    lda #<rsv_sect_bytes_str
+    ldx #>rsv_sect_bytes_str
+    jsr pushax
+
+    lda reserved_sectors
+    jsr pusha0
+    lda bytes_per_sector
+    ldx bytes_per_sector+1
+    jsr _imulii
+    jsr pushax
+    ldy #$4
+    jsr _cprintf
+
+    lda #<fat_size_tot_str
+    ldx #>fat_size_tot_str
+    jsr pushax
+
+    ; multiply fat size and number of fats
+
+    lda fat_count
+    jsr pusha0
+    lda sectors_per_fat
+    ldx sectors_per_fat+1
+    jsr _lmulii
+    jsr pusheax
+    ldy #$6
+    jsr _cprintf
+
+    rts
+.endproc