Merge branch 'fat32_sys_rewrite' of github.com:Nivirx/stevia into fat32_sys_rewrite

.gitignore

@@ -6,4 +6,5 @@ build/*
 bx_enh_dbg.ini
 stevia-log
 .vscode/
-*.map
+*.map
+compose-dev.yaml

bochsrc.bxrc

@@ -1,20 +1,18 @@
 # configuration file generated by Bochs
-plugin_ctrl: voodoo=false, unmapped=true, biosdev=true, speaker=true, extfpuirq=true, parallel=true, serial=true, busmouse=false, e1000=false, es1370=false, gameport=true, ne2k=false, sb16=false, usb_uhci=false, usb_ohci=false, usb_ehci=false, usb_xhci=false
+plugin_ctrl: voodoo=false, unmapped=true, biosdev=true, speaker=true, extfpuirq=true, parallel=true, serial=true, busmouse=false, e1000=false, es1370=false, gameport=true, iodebug=true, ne2k=false, sb16=false, usb_uhci=false, usb_ohci=false, usb_ehci=false, usb_xhci=false
 config_interface: win32config
 display_library: win32
 memory: guest=64, host=64, block_size=128
-romimage: file="C:\Program Files\Bochs-2.8\BIOS-bochs-latest", address=0x00000000, options=none, flash_data=none
+romimage: file="C:\Program Files\Bochs-2.8\BIOS-bochs-legacy", address=0x00000000, options=none, flash_data=none
 vgaromimage: file="C:\Program Files\Bochs-2.8\VGABIOS-lgpl-latest"
 boot: disk
-floppy_bootsig_check: disabled=0
+floppy_bootsig_check: disabled=1
 floppya: type=1_44
 # no floppyb
 ata0: enabled=true, ioaddr1=0x1f0, ioaddr2=0x3f0, irq=14
-ata0-master: type=disk, path=".\disk.img", mode=flat, cylinders=0, heads=0, spt=0, sect_size=512, model="Stevia Disk", biosdetect=auto, translation=lba
+ata0-master: type=disk, path=".\disk.img", mode=flat, cylinders=0, heads=16, spt=63, sect_size=512, model="Stevia Disk", biosdetect=auto, translation=auto
 ata0-slave: type=none
-ata1: type=none
+ata1: enabled=false
-ata1-master: type=none
-ata1-slave: type=none
 ata2: enabled=false
 ata3: enabled=false
 optromimage1: file=none
@@ -29,7 +27,10 @@ pci: enabled=1, chipset=i440fx, slot1=none, slot2=none, slot3=none, slot4=none,
 vga: extension=vbe, update_freq=10, realtime=1, ddc=builtin
 cpu: count=1, ips=1000000, model=p3_katmai, reset_on_triple_fault=1, cpuid_limit_winnt=0, ignore_bad_msrs=1, mwait_is_nop=0
 print_timestamps: enabled=0
-port_e9_hack: enabled=false, all_rings=false
+debugger_log: -
+magic_break: enabled=1
+port_e9_hack: enabled=true, all_rings=false
+iodebug: all_rings=0
 private_colormap: enabled=0
 clock: sync=none, time0=local, rtc_sync=0
 # no cmosimage
@@ -43,9 +44,9 @@ keyboard: type=mf, serial_delay=150, paste_delay=100000, user_shortcut=none
 mouse: type=none, enabled=false, toggle=ctrl+mbutton
 sound: waveoutdrv=dummy, waveout=none, waveindrv=dummy, wavein=none, midioutdrv=dummy, midiout=none
 speaker: enabled=true, mode=sound, volume=15
-parport1: enabled=true, file=none
+parport1: enabled=false
 parport2: enabled=false
-com1: enabled=true, mode=null
+com1: enabled=false
 com2: enabled=false
 com3: enabled=false
-com4: enabled=false
+com4: enabled=false

include/fat32/FAT32_SYS.inc

@@ -40,22 +40,18 @@ InitFATDriver:
     sub sp, 0x6
 
 .calc_active_part:
-    mov bx, [partition_offset]                     
+    mov ax, word [partition_offset]            
-    mov ax, partition_table
+    mov di, fat32_state
-    add ax, cx
-    mov si, ax                                  ; si = offset to active partition
-    
-    mov ax, fat32_state
-    mov di, ax
 
-    mov eax, dword [si + PartEntry_t.lba_start]
+    mov dx, partition_table
+    add dx, ax                                                           ; dx points to the partition that was booted from
+    mov bx, dx                                                           ; set bx, should point at our partition
+
+    mov eax, dword [bx + PartEntry_t.lba_start]
     mov dword [di + FAT32_State_t.curr_drive_lba_32], eax
 
-    mov ax, fat32_bpb
+    mov si, fat32_bpb
-    mov si, ax
+    mov bx, fat32_ebpb
-
-    mov ax, fat32_ebpb
-    mov bx, ax
 .calc_first_fat:
     movzx eax,  word [si + FAT32_bpb_t.reserved_sectors_word]        ; first fat from start of partition
     add   eax, dword [di + FAT32_State_t.curr_drive_lba_32]          ; calculate offset from start of drive
@@ -140,7 +136,7 @@ SearchFATDIR:
         add sp, 0x4
 
         cmp eax, 0x0fff_fff7
-        ;je SearchFATDIR.bad_cluster
+        ;je SearchFATDIR.bad_cluster            ; TODO: Implement Bad cluster checks
         jb SearchFATDIR.load_next_dir_next_OK
         ERROR STAGE2_FAT32_END_OF_CHAIN
 
@@ -197,7 +193,7 @@ SearchFATDIR:
 
             mov cx, 0xA                     ; max of 11 filename length of 11 characters
             ; si points to the start of the current directory entry
-            mov di, BootTarget_str          ; current memory location (8.3 name is at offset 0)
+            mov di, BootTarget              ; current memory location (8.3 name is at offset 0)
             repe cmpsb                      ; compare the strings
 
             pop di
@@ -257,7 +253,8 @@ NextCluster:
     add eax, ecx        ; fat_sector + first_fat_sector
     mov dword [si + FAT32_NextClusterData_t.fat_sector], eax
 .load_fat_table:
-    movzx ax, byte [boot_drive]
+    xor ax, ax
+    mov al, byte [boot_drive]
     push ax
 
     mov ax, 0x1
@@ -272,20 +269,6 @@ NextCluster:
 
     xor ax, ax
     push ax
-    ; BUG: something about this function causes this BIOS call to come back wrong
-    ; somehow the drive number is being read in wrong, but I can't find evidence of it being modified or writen
-    ; to memory incorrectly.
-    ; 00007109574i[BIOS  ] Booting from 0000:7c00
-    ; 00007123227i[CPU0  ] [7123227] Stopped on MAGIC BREAKPOINT
-    ; (0) Magic breakpoint
-    ; Next at t=7123227
-    ; (0) [0x000000000502] 0000:0502 (unk. ctxt): cli                       ; fa
-    ; <bochs:2> c
-    ; 00007252963i[BIOS  ] int13_diskette: unsupported AH=42
-    ; 00007253071i[CPU0  ] [7253071] Stopped on MAGIC BREAKPOINT
-    ; (0) Magic breakpoint
-    ; Next at t=7253071
-    ; (0) [0x00000000095c] 0000:095c (unk. ctxt): mov al, 0x47              ; b047
     call read_disk_raw  
     add sp, 0xC
     ; uint8_t read_stage2_raw(uint16_t buf_segment, uint16_t buf_offset, 
@@ -302,26 +285,6 @@ NextCluster:
 .error_cfdivz:
     ERROR STAGE2_FAT32_NCLUS_CFDIVZ
 
-; clobbers eax, edx
-; __fastcall16 uint32_t ClusterToLBA(uint32_t cluster)
-; input = dword cluster in eax
-ALIGN 4, db 0x90
-ClusterToLBA:
-    __FASTCALL16_ENTRY
-.func:
-    sub eax, 2
-    movzx edx, byte [fat32_bpb + FAT32_bpb_t.sectors_per_cluster_byte]
-    mul edx         ; result in eax, error on carry 
-    jc ClusterToLBA.error
-    add eax, dword [fat32_state + FAT32_State_t.first_data_sector_32]
-    jc ClusterToLBA.error
-    ; eax contains the LBA now
-.endp:
-    __FASTCALL16_EXIT
-    ret
-.error:
-    ERROR STAGE2_FAT32_CLS2LBA_CF
-
 ; uint8_t ReadFATCluster(uint16_t seg, uint16_t offset, uint32_t cluster)
 ALIGN 4, db 0x90
 ReadFATCluster:
@@ -329,14 +292,24 @@ ReadFATCluster:
 .func:
     print_string ReadFATCluster_info
 
-    movzx ax, byte [boot_drive]
+    mov bx, fat32_bpb
+    mov si, fat32_ebpb
+
+    xor ax, ax
+    mov al, byte [boot_drive]
     push ax
 
     mov ax, 0x1                         ; count = 1
     push ax
 
-    mov eax, dword [bp + 8]
+    mov eax, dword [bp + 8]             ; cluster
-    call ClusterToLBA                   ; __fastcall16 uint32_t ClusterToLBA(uint32_t cluster)
+    sub eax, 2
+    movzx edx, byte [bx + FAT32_bpb_t.sectors_per_cluster_byte]
+    mul edx                             ; result in eax, error on carry 
+    jc ReadFATCluster.error
+    add eax, dword [si + FAT32_State_t.first_data_sector_32]
+    jc ReadFATCluster.error
+    ; eax contains the LBA now
     push dword eax                      ; lba = ClusterToLBA(..)
 
     mov ax, word [bp + 6]               ; offset
@@ -352,6 +325,8 @@ ReadFATCluster:
 .endp:
     __CDECL16_EXIT
     ret
+.error:
+    ERROR STAGE2_FAT32_CLS2LBA_CF
 
 %endif
 %define __INC_FAT32_SYS

scripts/create-disk.sh

@@ -170,7 +170,7 @@ elif [[ "$OSTYPE" == "darwin"* ]]; then
         sfdisk_path="/usr/local/opt/util-linux/sbin/sfdisk"
         if [ -e $mbr_file ] && [ -e $vbr_file ]; then
         # use hdiutil to attach our empty disk image
-        ld_path_raw=$(hdiutil attach -readwrite -imagekey diskimage-class=CRawDiskImage -nomount -blocksize 512 -noverify disk.img)
+        ld_path_raw=$(hdiutil attach -readwrite -imagekey diskimage-class=CRawDiskImage -nomount -blocksize 512 -noverify /tmp/disk.img)
         ld=$(echo $ld_path_raw | sed s:/dev/::)
         ld_path="/dev/$ld"
 
@@ -193,7 +193,7 @@ elif [[ "$OSTYPE" == "darwin"* ]]; then
         unset ld
         unset ld_path_raw
 
-        ld_path_raw=$(hdiutil attach -readwrite -imagekey diskimage-class=CRawDiskImage -nomount -blocksize 512 -noverify disk.img)
+        ld_path_raw=$(hdiutil attach -readwrite -imagekey diskimage-class=CRawDiskImage -nomount -blocksize 512 -noverify /tmp/disk.img)
         ld=$(echo $ld_path_raw | grep "FDisk_partition_scheme" | awk '{print $1}' | sed s:/dev/::)
         ld_path="/dev/$ld"
 

src/stage2/stage2.nasm

@@ -49,15 +49,20 @@
 section .text
 begin_text:
 ; dl = byte boot_drive
-; si = word part_offset (active partition offset)
+; ax = word part_offset (active partition offset)
-; bx = ptr PartTable_t partition_table
+; si = ptr PartTable_t partition_table
-; dx = ptr FAT32_bpb_t fat32_bpb
+; di = ptr FAT32_bpb_t fat32_bpb
 ALIGN 4, db 0x90
 init:
-    __BOCHS_MAGIC_DEBUG
     cli                               ; We do not want to be interrupted
 
-    mov ax, __STAGE2_SEGMENT          ; set all our segments to the configured segment, excep es
+    ; these 4 are stored in the .data section and are effectivly const types
+    mov [vbr_part_table_ptr], si             ; pointer to partition_table
+    mov [vbr_fat32_bpb_ptr], di              ; pointer to fat32_bpb
+    mov [boot_drive], dl                     ; copy boot_drive to globals
+    mov [partition_offset], ax               ; copy partition_offset to globals
+
+    mov ax, __STAGE2_SEGMENT          ; set all our segments to the configured segment, except es
     mov ds, ax                        ; *
     mov fs, ax                        ; *
     mov gs, ax                        ; *
@@ -81,7 +86,7 @@ init:
 
     mov sp, stack_top
     mov bp, sp
-    sub sp, 0x20
+    sub sp, 0x10
     push bp                           ; setup a somewhat normal stack frame, minus a ret ptr
 
     sti
@@ -121,14 +126,9 @@ struc EarlyBootStruct_t
     .fat32_ebpb      resb FAT32_ebpb_t_size
 endstruc
 
-; bp - 4 : ptr PartTable_t partition_table
-; bp - 8 : ptr FAT32_bpb_t fat32_bpb
 ALIGN 4, db 0x90
 main:
-    mov byte [boot_drive], dl                              ; boot_drive (probably 0x80)
+    __BOCHS_MAGIC_DEBUG
-    mov word [partition_offset], si                        ; partition_offset
-    mov word [bp - 4], bx                                  ; partition_table_vbr
-    mov word [bp - 8], dx                                  ; fat32_bpb_vbr
 .check_sig:
     mov eax, dword [STAGE2_SIG]
     cmp eax, 0xDEADBEEF
@@ -136,21 +136,21 @@ main:
     ERROR STAGE2_SIGNATURE_MISSING
 .stage2_main:
     mov ax, PartTable_t_size
+    push ax                                                 ; len = PartTable_t_size
+    mov ax, word [vbr_part_table_ptr]                       ; src = ptr to vbr partition_table
     push ax
-    mov ax, [bp - 4]                                    ; ptr partition_table
+    mov ax, partition_table                                 ; dst
     push ax
-    mov ax, partition_table                                  
+    call kmemcpy                                            ; copy partition table data to .data section in stage2
-    push ax
-    call kmemcpy                                        ; copy partition table data
     add sp, 0x6
 
-    mov ax, (FAT32_bpb_t_size + FAT32_ebpb_t_size)      ; size in byte
+    mov ax, (FAT32_bpb_t_size + FAT32_ebpb_t_size)          ; len
     push ax
-    mov ax, [bp - 8]                                    
+    mov ax, word [vbr_fat32_bpb_ptr]                        ; src            
     push ax
-    mov ax, fat32_bpb                                   ; defined in memory.inc, destination
+    mov ax, fat32_bpb                                       ; dst
     push ax
-    call kmemcpy                                        ; copy bpb & ebpb to memory
+    call kmemcpy                                            ; copy bpb & ebpb to memory
     add sp, 0x6
 
     call SetTextMode
@@ -161,14 +161,14 @@ main:
     call EnableA20
     print_string A20_Enabled_OK_info
 
-    ; enter unreal mode
-    call EnterUnrealMode
-    print_string UnrealMode_OK_info
-
     ; get system memory map
     call GetMemoryMap
     print_string MemoryMap_OK_info
 
+    ; enter unreal mode
+    call EnterUnrealMode
+    print_string UnrealMode_OK_info
+
     ; FAT Driver setup
     call InitFATDriver
     print_string InitFATSYS_OK_info
@@ -389,12 +389,32 @@ define_info NextFATCluster, "Attempting to find next FAT cluster..."
 define_info ReadFATCluster, "Attempting to load next FAT"
 define_info MaybeFound_Boot, "Maybe found a file...checking..."
 
-define_cstr BootTarget, "BOOT    BIN"
+define_cstr BootTarget_cstr, "BOOT    BIN"
 
 ALIGN 16, db 0
-BootTarget_str:
+BootTarget:
     db 'BOOT    BIN'
 
+;
+; pre-bss init globals (generally const...but there are exceptions)
+;
+
+align 8, db 0x00
+boot_drive:
+    db 0x00
+
+align 8, db 0x00
+partition_offset:
+    dw 0x0000
+
+align 8, db 0x00
+vbr_fat32_bpb_ptr:
+    dw 0x0000
+
+align 8, db 0x00
+vbr_part_table_ptr:
+    dw 0x0000
+
 ALIGN 16
 IntToHex_table:
     db '0123456789ABCDEF'
@@ -489,37 +509,29 @@ section .bss follows=.sign
 begin_bss:
 ; structures
 
-align 16, resb 1
+align 8, resb 1
 partition_table resb PartTable_t_size
 
-align 16, resb 1
+align 8, resb 1
 fat32_bpb resb FAT32_bpb_t_size
 fat32_ebpb resb FAT32_ebpb_t_size
 
-align 16, resb 1
+align 8, resb 1
 fat32_nc_data resb 16
 
-align 16, resb 1
+align 8, resb 1
 lba_packet resb LBAPkt_t_size
 
-align 16, resb 1
+align 8, resb 1
 fat32_state:
     resb FAT32_State_t_size
 
-align 16, resb 1
+align 8, resb 1
 SteviaInfo:
     resd 4
-
 ;
-; locals
+; post-bss init globals
 ;
-ALIGN 4,resb 1
-boot_drive:
-    resb 1
-
-ALIGN 4,resb 1
-partition_offset:
-    resw 1
 
 ;
 ; large continuous allocations

src/vbr/vbr.nasm

@@ -152,10 +152,10 @@ main:
     call read_disk_raw
     add sp, 0xC
 .enter_stage2:
-    mov dl, byte [bp - 2]               ; boot_drive
+    mov dl, byte [bp - 2]               ; byte boot_drive
-    mov si, word [bp - 4]               ; part_offset
+    mov ax, word [bp - 4]               ; word part_offset
-    mov bx, partition_table
+    mov si, partition_table             ; ptr partition_table
-    mov dx, fat32_bpb
+    mov di, fat32_bpb                   ; ptr fat32_bpb
     jmp word 0x0000:STAGE2_ENTRY
 
 ; ###############