Clean-up and conveniance for mbr and loader
This commit is contained in:
Adrien Bourmault
parent
bcff95e6d0
commit
a805431f7c
BIN
bin/disk.img
BIN
bin/disk.img
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BIN
bin/loader.bin
BIN
bin/loader.bin
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BIN
bin/mbr.bin
BIN
bin/mbr.bin
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BIN
obj/boot/mbr.bin
BIN
obj/boot/mbr.bin
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@ -29,7 +29,7 @@ SYSTDIR=kaleid/system
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all: bootloader
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boot.mbr.s: $(BOOTDIR)/mbr.s
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boot.mbr.s: $(BOOTDIR)/mbr.s $(BOOTDIR)/mbr.inc
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$(ASM) $(BOOTFLAGS) $(BOOTDIR)/mbr.s -o $(OBJDIR)/boot/mbr.bin
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boot.loader.s: $(BOOTDIR)/loader.s
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@ -7,8 +7,12 @@
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; Desc: Kernel (second stage) Loader for OS/K ;
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; (x86_64 architecture only) ;
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;=----------------------------------------------------------------------------=;
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;;VIDEO
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%define TRAM 0x0B8000 ; [T]ext[RAM]
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%define VRAM 0x0A0000 ; [V]ideo[RAM]
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;; BPB
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%define OEMName bp+0x03 ; Disk label
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%define bytesPerSector bp+0x0b ; Bytes per sector
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%define sectorsPerCluster bp+0x0d ; Sectors per cluster
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@ -32,9 +36,9 @@
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[BITS 16]
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[ORG 0x1000]
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mov ax, cs
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mov ds, ax
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mov es, ax
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mov ax, cs ; correcting cs after the horrible far jump
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mov ds, ax ; hm... And ds too
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mov es, ax ; And es because it is jealous
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mov [Bootdrv], dl
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jmp 0x0000:main
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@ -48,13 +52,13 @@ VIDEO_MODE dw 0
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;; GDT WITH DOC
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GDT64:
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NULL_SELECTOR: ;; null selector within 64 bits
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dw GDT_LENGTH ; limit of GDT
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dw GDT64 ; linear address of GDT
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dw GDT_LENGTH ; limit of GDT
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dw GDT64 ; linear address of GDT
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dd 0x0
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CODE_SELECTOR: ;; 32-bit code selector (ring 0)
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dw 0x0FFFF ; Segment Limit 15:00
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db 0x0, 0x0, 0x0 ; Base Address 23:00
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db 10011010b ; |7|6|5|4|3|2|1|0|
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dw 0x0FFFF ; Segment Limit
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db 0x0, 0x0, 0x0 ; Base Address
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db 10011010b ; |7|6|5|4|3|2|1|0|
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; | | | | | | | `----- 1 when segment used.
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; | | | | | | `------ 1 when writable.
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; | | | | | `------- 1 if "conformant". Don't know what is it... spectral ? xD
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@ -63,7 +67,7 @@ GDT64:
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; | | `---------- DPL !!! 0 for ring 0
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; | `----------- DPL (2/2)
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; `------------ 1 if in physical memory, 0 if page fault
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db 11001111b ; |7|6|5|4|3|2|1|0|
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db 11001111b ; |7|6|5|4|3|2|1|0|
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; | | | | | | | `----- Limit 16
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; | | | | | | `------ Limit 17
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; | | | | | `------- Limit 18
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@ -72,12 +76,12 @@ GDT64:
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; | | `---------- 0 always
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; | `----------- size of data. 1 for 32bits
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; `------------ 0 if limit is in Bytes, 1 if it's in pages (4ko)
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db 0x0 ; Base Address 31:24
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db 0x0 ; Base Address
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DATA_SELECTOR: ;; flat data selector (ring 0)
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dw 0x0FFFF ; Segment Limit 15:00
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db 0x0, 0x0, 0x0 ; Base Address 23:00
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db 10010010b ; |7|6|5|4|3|2|1|0|
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DATA_SELECTOR: ;; flat data selector (ring 0)
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dw 0x0FFFF ; Segment Limit
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db 0x0, 0x0, 0x0 ; Base Address
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db 10010010b ; |7|6|5|4|3|2|1|0|
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; | | | | | | | `----- 1 when segment used.
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; | | | | | | `------ 1 when writable.
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; | | | | | `------- expansion direction. 1 for a LIFO
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@ -86,7 +90,7 @@ GDT64:
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; | | `---------- DPL !!! 0 for ring 0
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; | `----------- DPL (2/2)
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; `------------ 1 if in physical memory, 0 if page fault
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db 10001111b ; |7|6|5|4|3|2|1|0|
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db 10001111b ; |7|6|5|4|3|2|1|0|
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; | | | | | | | `----- Limit 16
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; | | | | | | `------ Limit 17
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; | | | | | `------- Limit 18
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@ -95,12 +99,12 @@ GDT64:
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; | | `---------- 0 always
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; | `----------- size of data. 1 for 32bits
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; `------------ 0 if limit is in Bytes, 1 if it's in pages (4ko)
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db 0x0 ; Base Address 31:24
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db 0x0 ; Base Address
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LONG_SELECTOR: ;; 64-bit code selector (ring 0)
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dw 0x0FFFF ; Segment Limit 15:00
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db 0x0, 0x0, 0x0 ; Base Address 23:00
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db 10011010b ; |7|6|5|4|3|2|1|0|
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dw 0x0FFFF ; Segment Limit
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db 0x0, 0x0, 0x0 ; Base Address
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db 10011010b ; |7|6|5|4|3|2|1|0|
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; | | | | | | | `----- 1 when segment used.
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; | | | | | | `------ 1 when writable.
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; | | | | | `------- 1 if "conformant". Don't know what is it... spectral ? xD
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@ -118,89 +122,10 @@ GDT64:
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; | | `---------- 0 always
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; | `----------- size of data. 1 for 32bits
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; `------------ 0 if limit is in Bytes, 1 if it's in pages (4ko)
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db 0x0 ; Base Address 31:24
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db 0x0 ; Base Address
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GDT_LENGTH:
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disable_cursor:
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pushf
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push eax
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push edx
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mov dx, 0x3D4
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mov al, 0xA ; low cursor shape register
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out dx, al
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inc dx
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mov al, 0x20 ; bits 6-7 unused, bit 5 disables the cursor, bits 0-4 control the cursor shape
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out dx, al
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pop edx
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pop eax
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popf
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ret
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get_dimensions:
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push eax
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push ebx
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mov ah, 0x0F
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int 0x10
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mov [VGA_HEIGHT], ah
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mov [VIDEO_MODE], al
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pop ebx
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pop eax
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ret
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;-----------------------------------------------------------------------;
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; Checks if the CPU is compatible with 64-bits operating systems ;
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; If the 21th bit of the eax register is set, then CPUID is supported ;
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; We then test CPUID's result to see if long mode is supported ;
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;-----------------------------------------------------------------------;
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Is64bits:
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pushfd ; recovering the flags in eax
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pop eax
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mov ecx, eax
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xor eax, 0x200000
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push eax
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popfd
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pushfd
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pop eax
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xor eax, ecx
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shr eax, 21
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and eax, 1 ; magical spell of murta
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push ecx
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popfd
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test eax, eax
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jz .NonCompat ; if (CPUID non supporté) goto NonCompat
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mov eax, 0x80000000
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cpuid
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cmp eax, 0x80000001
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jb .NonCompat ; if (eax <= 0x80000001) goto NonCompat
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mov eax, 0x80000001
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cpuid
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test edx, 1 << 29
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jz .NonCompat ; if (edx != 1 << 29) goto NonCompat
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ret ; back to mbr.s
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.NonCompat:
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stc
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ret
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PrintB:
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;---------------------------------------------------;
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; Print out a simple string. ;
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; ;
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; Expects: DS:SI = String to print ;
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; ;
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; Returns: None ;
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; ;
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;---------------------------------------------------;
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lodsb ; Load byte from ds:si to al
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or al, al ; If al is empty stop looping
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jz .done ; Done looping and return
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mov ah, 0x0e ; Teletype output
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int 0x10 ; Video interupt
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jmp PrintB ; Loop untill string is null
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.done:
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ret
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%include "boot/loader16.inc"
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main:
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;; compatibility check
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@ -308,74 +233,12 @@ main32:
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push dword [VGA_HEIGHT]
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jmp (LONG_SELECTOR-GDT64):main64
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[BITS 64]
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;; FUNCTIONS
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clear:
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;-----------------------------------------------------------------------;
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; x64/LM Clear Text Screen Function ;
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;-----------------------------------------------------------------------;
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mov qword [NextTRAM], TRAM
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mov edi, TRAM
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push rsi
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push rdi
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push rcx
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mov ah, 0
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mov al, 0
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mov rcx, 0x4000 ; traditionnal value
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rep stosw ; fill screen with al while cx > 0
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pop rcx
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pop rsi
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pop rdi
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ret
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[BITS 64]
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write:
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;-----------------------------------------------------------------------;
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; x64/LM Text Printing Functions ;
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; bl : color code ;
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; esi : string address ;
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;-----------------------------------------------------------------------;
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mov edi, [NextTRAM] ;TRAM ADDRESS
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push rsi
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push rdi
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.pLoop:
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lodsb
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cmp al, 0 ; while @al, i.e. while we're not hitting '\0'
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je .pEnd
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cmp al, 0x0A ; LF
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je .lf
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cmp al, 0x0D ; CR
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je .cr
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stosb ; text subpixel
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mov al, bl
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stosb ; color subpixel
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add qword [NextTRAM], 0x2 ; Cursor moving
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add qword [VGA_X], 0x2 ; coord + 2 because 2 subpixels
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jmp .pLoop
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.pEnd:
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pop rdi
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pop rsi
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ret
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.lf:
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mov rax, [VGA_HEIGHT64]
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add [NextTRAM], rax ; Cursor moving
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add [NextTRAM], rax
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add edi, eax ; Address moving
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add edi, eax
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jmp .pLoop
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.cr:
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push rax
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mov rax, qword [VGA_X]
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sub qword [NextTRAM], rax ; pos = X + Y * VGA_HEIGHT64. Donc pos - X = début de ligne
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sub edi, edx
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mov qword [VGA_X], 0
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pop rax
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jmp .pLoop
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.scroll:
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jmp .pLoop
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%include "boot/loader64.inc"
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;; DATA
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txt db 0x09, " Switching to Long Mode... OK", 0x0A, 0x0D, 0
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txt db 0x09, " Switching to Long Mode... ", 0
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Init db "Booting OS/K !", 0x0D, 0x0A, 0x0D, 0x0A, 0x09, " Checking CPUID...",0
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Reinit db "Booting OS/K !", 0x0D, 0x0A, 0x0D, 0x0A, 0
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CPUIDD db 0x09, " Checking CPUID...", 0
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@ -417,10 +280,14 @@ main64:
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mov esi, Pass
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call write
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mov bl, 0x0A
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mov bl, 0x0F
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mov esi, txt
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call write
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mov bl, 0x0A
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mov esi, Pass
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call write
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mov bl, 0x0D
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mov esi, msg
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call write
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@ -434,5 +301,4 @@ ErrorNo64:
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Die:
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cli
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hlt ; die nooooow
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retf
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KERNEL:
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jmp 0xF000:0xFFF0
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194
src/boot/mbr.s
194
src/boot/mbr.s
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@ -24,16 +24,16 @@
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%define LOAD_SEG 0x0000 ; (LOAD_SEG << 4) + LOAD_OFF = 0x001000
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%define LOAD_OFF 0x1000
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[BITS 16] ; Ensure 16-bit code (because fuck UEFI)
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[BITS 16] ; Ensure 16-bit code (because fuck UEFI)
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;---------------------------------------------------;
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; Disk description table ;
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;---------------------------------------------------;
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Intro:
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jmp short _start ; Jump over the BIOS PARAMETER BLOCK
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nop ; Required by BIOS to recognize the Disk
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nop ; Required by BIOS to recognize the Disk loul
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BPB:
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;---------------------------------------------------;
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; Disk description table ;
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;---------------------------------------------------;
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%define OEMName bp+0x03 ; Disk label
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%define bytesPerSector bp+0x0b ; Bytes per sector
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%define sectorsPerCluster bp+0x0d ; Sectors per cluster
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@ -53,7 +53,8 @@ BPB:
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%define volumeId bp+0x27 ; Volume ID
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%define volumeLabel bp+0x2b ; Volume Label
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%define fatTypeLabel bp+0x36 ; File system type
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times 0x3b db 0x00
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times 0x3b db 0x00 ; ALLOCATE THE SECTORS FOR THE BPB
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;; ENTRY POINT
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_start:
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@ -63,11 +64,11 @@ bootstrap:
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jmp go
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;; LOVELY DATA
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FileNotFound db "FStage ERR : NO LOADER", 0 ; File was not found
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DiskError db "FStage ERR : DISK", 0 ; Error while reading from the disk
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UserData dw 0 ; Start of the data sectors
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Bootdrv db 0 ; Boot Bootdrv number
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filename db "LOADER BIN" ; Filename
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FileNotFound db "First Stage ERROR : NO LOADER", 0
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DiskError db "First Stage ERROR : DISK", 0
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UserData dw 0
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Bootdrv db 0
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filename db "LOADER BIN"
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;; GO !
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@ -82,7 +83,7 @@ go:
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mov ss, ax ; Continue init the staaaaaaaack
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mov sp, STACK_OFF ; Ok man, the stack is in 4K :O
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sti
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mov bp, (0x7c0-STACK_SEG) << 4 ; Correct bp for the disk description table !
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mov bp, (0x7c0-STACK_SEG) << 4 ; Correct bp (the disk description table)
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;; INITIALIZE BOOT DISK
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or dl, dl ; Verifying dl points actually to the boot drive
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@ -116,7 +117,7 @@ load_root:
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mov di, BUFFER_SEG ; Set the extra segment to the disk buffer
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mov es, di
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mov di, BUFFER_OFF ; Set es:di and load the root directory into the disk buffer
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call read_sectors ; Read the sectoooooooors !
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call read_sectors ; Read the sectoooooooors !
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;; FIND THE SECOND STAGE LOADER
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mov di, BUFFER_OFF ; Set es:di to the disk buffer
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@ -127,30 +128,17 @@ search_root:
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mov si, filename ; Load the filename
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mov cx, 11 ; Compare first 11 bytes
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rep cmpsb ; Compare si and di cx times
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je load_fat ; We found the LOADEEEEEEEER!!!
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je load_fat ; We found the LOADEEEEEEEER!!!
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add ax, 32 ; File entry offset
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mov di, BUFFER_OFF ; Point back to the start of the entry
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add di, ax ; Add the offset to point to the next entry
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xchg dx, cx
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loop search_root ; Continue to search for the file
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loop search_root ; Continue to search for the file
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;; ERROR...
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mov si, FileNotFound ; Could not find the file
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call print
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;; REBOOT
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reboot:
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xor ax, ax
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int 0x16 ; Get a single keypress
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mov ah, 0x0e ; Teletype output
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mov al, 0x0d ; Carriage return
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int 0x10 ; Video interupt
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mov al, 0x0a ; Line feed
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int 0x10 ; Video interupt
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mov al, 0x0a ; Line feed
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int 0x10 ; Video interupt
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xor ax, ax
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int 0x19 ; Reboot the system
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call reboot
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;; LOAD THE FAT FROM THE FILE
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load_fat:
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@ -162,7 +150,7 @@ load_fat:
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mov cx, ax ; Store in cx
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mov ax, word [reservedSectors] ; Convert the first fat on the disk
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mov di, BUFFER_OFF ; Set es:di and load the fat sectors into the disk buffer
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call read_sectors ; Read the sectooooooooooors !!!
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call read_sectors ; Read the sectooooooooooors !!!
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;; LOAD THE CLUSTERS OF THE LOADER AND JUMP
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mov di, LOAD_SEG
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@ -178,152 +166,10 @@ load_fat:
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; ...
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; I hope....
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; ...
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call reboot
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;---------------------------------------------------;
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; FUNCTIONS ;
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;---------------------------------------------------;
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read_clusters:
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;---------------------------------------------------;
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; Read file clusters, starting at the given cluster,;
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; expects FAT to be loaded into the disk buffer. ;
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; Please note that this may allocate up to 128KB ;
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; of ram. ;
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; ;
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; Expects: AX = Starting cluster ;
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; ES:DI = Location to load clusters ;
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; ;
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; Returns: None ;
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; ;
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;---------------------------------------------------;
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pusha
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push es
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.cluster_loop:
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xor bh, bh
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xor dx, dx
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push ax ; Get the cluster start = (cluster - 2) * sectorsPerCluster + UserData
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sub ax, 2 ; Subtract 2
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mov bl, byte [sectorsPerCluster] ; Sectors per cluster is a byte value
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mul bx ; multiply (cluster - 2) * sectorsPerCluster
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add ax, word [UserData] ; add the UserData
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xor ch, ch
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mov cl, byte [sectorsPerCluster] ; Sectors to read
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call read_sectors ; Read the sectors
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pop ax ; Current cluster number
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xor dx, dx
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;; Calculate next sector for FAT16 (cluster * 2)
|
||||
mov bx, 2 ; Multiply the cluster by two (cluster is in ax)
|
||||
mul bx
|
||||
;; Load sector in RAM
|
||||
push ds
|
||||
push si
|
||||
mov si, BUFFER_SEG
|
||||
mov ds, si ; Temporarly set ds:si to the FAT buffer
|
||||
mov si, BUFFER_OFF
|
||||
add si, ax ; Point to the next cluster in the FAT entry
|
||||
mov ax, word [ds:si] ; Load ax to the next cluster in FAT
|
||||
pop si
|
||||
pop ds
|
||||
;; Next
|
||||
cmp ax, 0xfff8 ; Check if we are at the end of the file?
|
||||
jae .done
|
||||
add di, 512 ; Add to the pointer offset
|
||||
jnc .cluster_loop
|
||||
;; Correct the buffer because an error will occur if the buffer in memory
|
||||
mov dx, es ; overlaps a 64k page boundry, when di overflows
|
||||
add dh, 0x10 ; it will trigger the carry flag, so correct
|
||||
mov es, dx ; extra segment by 0x1000
|
||||
jmp .cluster_loop ; Load the next file cluster
|
||||
.done:
|
||||
pop es
|
||||
popa
|
||||
ret
|
||||
|
||||
|
||||
read_sectors:
|
||||
;---------------------------------------------------;
|
||||
; Read sectors starting at a given sector by ;
|
||||
; the given times and load into a buffer. Please ;
|
||||
; note that this may allocate up to 128KB of ram. ;
|
||||
; ;
|
||||
; Expects: AX = Starting sector ;
|
||||
; CX = Number of sectors to read ;
|
||||
; ES:DI = Location to load sectors ;
|
||||
; ;
|
||||
; Returns: None ;
|
||||
; ;
|
||||
;---------------------------------------------------;
|
||||
pusha
|
||||
push es
|
||||
mov bx, di ; Convert es:di to es:bx for int 13h
|
||||
.sector_loop:
|
||||
push ax
|
||||
push cx
|
||||
xor dx, dx
|
||||
div word [sectorsPerTrack] ; Divide the lba (value in ax) by sectorsPerTrack
|
||||
mov cx, dx ; Save the absolute sector value
|
||||
inc cx
|
||||
xor dx, dx ; Divide by the number of heads
|
||||
div word [heads] ; to get absolute head and track values
|
||||
mov dh, dl ; Move the absolute head into dh
|
||||
mov ch, al ; Low 8 bits of absolute track
|
||||
shl ah, 1 ; High 2 bits of absolute track
|
||||
shl ah, 1
|
||||
shl ah, 1
|
||||
shl ah, 1
|
||||
shl ah, 1
|
||||
shl ah, 1
|
||||
or cl, ah ; Now cx is set with respective track and sector numbers
|
||||
mov dl, byte [Bootdrv] ; Set correct Bootdrv for int 13h
|
||||
mov di, 5 ; Try five times to read the sector because i love 5
|
||||
.attempt_read:
|
||||
mov ax, 0x0201 ; Read Sectors func of int 13h, read one sector
|
||||
int 0x13 ; Call int 13h (BIOS disk I/O)
|
||||
jnc .read_ok ; If no carry set, the sector has been read
|
||||
xor ah, ah ; Reset Bootdrv func of int 13h
|
||||
int 0x13 ; Call int 13h (BIOS disk I/O)
|
||||
dec di ; Decrease read attempt counter
|
||||
jnz .attempt_read ; Try to read the sector again
|
||||
mov si, DiskError ; Error reading the disk :/
|
||||
call print
|
||||
jmp reboot
|
||||
.read_ok:
|
||||
pop cx
|
||||
pop ax
|
||||
inc ax ; Increase the next sector to read
|
||||
add bx, word [bytesPerSector] ; Add to the buffer address for the next sector
|
||||
jnc .next_sector
|
||||
;; Fixing buffer because an error will occur if the buffer in memory
|
||||
mov dx, es ; overlaps a 64k page boundry, when bx overflows
|
||||
add dh, 0x10 ; it will trigger the carry flag, so correct
|
||||
mov es, dx ; es segment by 0x1000
|
||||
.next_sector:
|
||||
loop .sector_loop
|
||||
pop es
|
||||
popa
|
||||
ret
|
||||
|
||||
print:
|
||||
;---------------------------------------------------;
|
||||
; Print out a simple string. ;
|
||||
; ;
|
||||
; Expects: DS:SI = String to print ;
|
||||
; ;
|
||||
; Returns: None ;
|
||||
; ;
|
||||
;---------------------------------------------------;
|
||||
lodsb ; Load byte from ds:si to al
|
||||
or al, al ; If al is empty stop looping
|
||||
jz .done ; Done looping and return
|
||||
mov ah, 0x0e ; Teletype output
|
||||
int 0x10 ; Video interupt
|
||||
jmp print ; Loop untill string is null
|
||||
.done:
|
||||
ret
|
||||
%include "boot/mbr.inc"
|
||||
|
||||
;; END
|
||||
times 510 - ($ - $$) db 0 ; Pad remainder of boot sector with zeros
|
||||
dw 0xaa55 ; Boot signature
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue