diff --git a/Makefile b/Makefile index e990b7d..6458c3c 100644 --- a/Makefile +++ b/Makefile @@ -29,15 +29,16 @@ ASM=nasm ASMFLAGS= BOOTFLAGS=-f bin -BOOTDIR=boot +MBRDIR=boot/mbr +LOADERDIR=boot/loader OBJDIR=build/obj BINDIR=build/bin -boot.mbr.asm: $(BOOTDIR)/mbr.asm $(BOOTDIR)/mbr.inc - $(ASM) $(BOOTFLAGS) $(BOOTDIR)/mbr.asm -o $(OBJDIR)/boot/mbr.bin +boot.mbr.asm: $(MBRDIR)/mbr.asm $(MBRDIR)/mbr.inc + $(ASM) $(BOOTFLAGS) $(MBRDIR)/mbr.asm -o $(OBJDIR)/boot/mbr.bin -boot.loader.asm: $(BOOTDIR)/loader.asm - $(ASM) $(BOOTFLAGS) $(BOOTDIR)/loader.asm -o $(OBJDIR)/boot/loader.bin +boot.loader.asm: $(LOADERDIR)/loader.asm + $(ASM) $(BOOTFLAGS) $(LOADERDIR)/loader.asm -o $(OBJDIR)/boot/loader.bin bootloader: boot.mbr.asm boot.loader.asm cp $(OBJDIR)/boot/mbr.bin $(BINDIR)/mbr.bin diff --git a/boot/elf/elf.c b/boot/elf/elf.c deleted file mode 100644 index 1781d7b..0000000 --- a/boot/elf/elf.c +++ /dev/null @@ -1,10 +0,0 @@ -//----------------------------------------------------------------------------// -// GNU GPL OS/K // -// // -// Authors: spectral` // -// NeoX // -// // -// Desc: ELF64 Parser and Loader // -//----------------------------------------------------------------------------// - -//STUB diff --git a/boot/loader.asm b/boot/loader.asm deleted file mode 100644 index 43f5fe8..0000000 --- a/boot/loader.asm +++ /dev/null @@ -1,357 +0,0 @@ -;=----------------------------------------------------------------------------=; -; GNU GPL OS/K ; -; ; -; Authors: spectral` ; -; NeoX ; -; ; -; Desc: Kernel (second stage) Loader for OS/K ; -; (x86_64 architecture only) ; -;=----------------------------------------------------------------------------=; - -;;VIDEO -%define TRAM 0x0B8000 ; [T]ext[RAM] -%define VRAM 0x0A0000 ; [V]ideo[RAM] - -;; BPB -%define OEMName bp+0x03 ; Disk label -%define bytesPerSector bp+0x0b ; Bytes per sector -%define sectorsPerCluster bp+0x0d ; Sectors per cluster -%define reservedSectors bp+0x0e ; Reserved sectors -%define fats bp+0x10 ; Number of fats -%define rootDirEntries bp+0x11 ; Number of entries in root dir -%define sectors bp+0x13 ; Logical sectors -%define mediaType bp+0x15 ; Media descriptor byte -%define fatSectors bp+0x16 ; Sectors per FAT -%define sectorsPerTrack bp+0x18 ; Sectors per track -%define heads bp+0x1a ; Number of sides/heads -%define hiddenSectors bp+0x1c ; Hidden sectors -%define hugeSectors bp+0x20 ; LBA sectors -%define biosBootdrvNum bp+0x24 ; Bootdrv number -%define reserved bp+0x25 ; This is not used -%define bootSignature bp+0x26 ; Bootdrv signature -%define volumeId bp+0x27 ; Volume ID -%define volumeLabel bp+0x2b ; Volume Label -%define fatTypeLabel bp+0x36 ; File system type - - - -[BITS 16] -[ORG 0x1000] - -mov ax, cs ; correcting cs after the horrible far jump -mov ds, ax ; hm... And ds too -mov es, ax ; And es because it is jealous - -mov [Bootdrv], dl -xor dl, dl -jmp 0x0000:main - -;; GDT WITH DOC -GDT64: - NULL_SELECTOR: ;; null selector within 64 bits - dw GDT_LENGTH ; limit of GDT - dw GDT64 ; linear address of GDT - dd 0x0 ; - - CODE_SELECTOR: ;; 32-bit code selector (ring 0) - dw 0x0000FFFF ; Segment Limit - db 0x0, 0x0, 0x0 ; Base Address - db 10011010b ; |7|6|5|4|3|2|1|0| - ; | | | | | | | `----- 1 when segment used. - ; | | | | | | `------ 1 when writable. - ; | | | | | `------- 1 if "conformant". Don't know what is it... spectral ? xD - ; | | | | `-------- 1 always - ; | | | `--------- 1 for segment descriptor, 0 for system descriptor - ; | | `---------- DPL !!! 0 for ring 0 - ; | `----------- DPL (2/2) - ; `------------ 1 if in physical memory, 0 if page fault - db 11001111b ; |7|6|5|4|3|2|1|0| - ; | | | | | | | `----- Limit 16 - ; | | | | | | `------ Limit 17 - ; | | | | | `------- Limit 18 - ; | | | | `-------- Limit 19 - ; | | | `--------- available for use - ; | | `---------- 0 always - ; | `----------- size of data. 1 for 32bits - ; `------------ 0 if limit is in Bytes, 1 if it's in pages (4ko) - db 0x0 ; Base Address - - DATA_SELECTOR: ;; flat data selector (ring 0) - dw 0x0000FFFF ; Segment Limit - db 0x0, 0x0, 0x0 ; Base Address - db 10010010b ; |7|6|5|4|3|2|1|0| - ; | | | | | | | `----- 1 when segment used. - ; | | | | | | `------ 1 when writable. - ; | | | | | `------- expansion direction. 1 for a LIFO - ; | | | | `-------- 1 always - ; | | | `--------- 1 for segment descriptor, 0 for system descriptor - ; | | `---------- DPL !!! 0 for ring 0 - ; | `----------- DPL (2/2) - ; `------------ 1 if in physical memory, 0 if page fault - db 10001111b ; |7|6|5|4|3|2|1|0| - ; | | | | | | | `----- Limit 16 - ; | | | | | | `------ Limit 17 - ; | | | | | `------- Limit 18 - ; | | | | `-------- Limit 19 - ; | | | `--------- available for use - ; | | `---------- 0 always - ; | `----------- size of data. 1 for 32bits - ; `------------ 0 if limit is in Bytes, 1 if it's in pages (4ko) - db 0x0 ; Base Address - - LONG_SELECTOR: ;; 64-bit code selector (ring 0) - dw 0x0000FFFF ; Segment Limit - db 0x0, 0x0, 0x0 ; Base Address - db 10011010b ; |7|6|5|4|3|2|1|0| - ; | | | | | | | `----- 1 when segment used. - ; | | | | | | `------ 1 when writable. - ; | | | | | `------- 1 if "conformant". Don't know what is it... spectral ? xD - ; | | | | `-------- 1 always - ; | | | `--------- 1 for segment descriptor, 0 for system descriptor - ; | | `---------- DPL !!! 0 for ring 0 - ; | `----------- DPL (2/2) - ; `------------ 1 if in physical memory, 0 if page fault - db 10101111b ; |7|6|5|4|3|2|1|0| - ; | | | | | | | `----- Limit 16 - ; | | | | | | `------ Limit 17 - ; | | | | | `------- Limit 18 - ; | | | | `-------- Limit 19 - ; | | | `--------- available for use - ; | | `---------- 0 always - ; | `----------- size of data. 1 for 32bits - ; `------------ 0 if limit is in Bytes, 1 if it's in pages (4ko) - db 0x0 ; Base Address - GDT_LENGTH: - -%include "boot/loader16.inc" - -main: - - ;; compatibility check - push si - mov si, Init - call PrintB - pop si - call Is64bits - jc ErrorNo64 - push si - mov si, Pass - call PrintB - pop si - - ;; Enabling A20 - push si - mov si, EnA20 - call PrintB - pop si - in al, 0x92 - or al, 2 - out 0x92, al - push si - mov si, Pass - call PrintB - pop si - - ;; DISABLING CURSOR BLINKING AND GETTING INFOS - call get_dimensions - call disable_cursor - - ;;GO GDT64 - cli ; disable interrupts - lgdt [GDT64] - ;; ACTIVATE PROTECTED MODE - mov eax, cr0 - or al, 1b ; PE = 1 - mov cr0, eax - ;; DISABLE PAGING - mov eax, cr0 - and eax, 0x7FFFFFFF ; PG = 0 - ; |0|111111111111111111111111111111 - ; | - ; `------ Paging bit - mov cr0, eax - - push dword [VIDEO_MODE] - push dword [VGA_HEIGHT] - jmp (CODE_SELECTOR-GDT64):main32 - -ErrorNo64: - mov si, NoLongMode - call PrintB -Die: - cli - hlt ; die nooooow - jmp 0xF000:0xFFF0 - -[BITS 32] -main32: - pop dword [VGA_HEIGHT32] - pop dword [VIDEO_MODE32] - - ;; VERIFY A20 - pushad - mov edi,0x112345 ;odd megabyte address. - mov esi,0x012345 ;even megabyte address. - mov [esi],esi ;making sure that both addresses contain diffrent values. - mov [edi],edi ;(if A20 line is cleared the two pointers would point to the address 0x012345 that would contain 0x112345 (edi)) - cmpsd ;compare addresses to see if the're equivalent. - popad - jne .A20_on ;if not equivalent , A20 line is set. - mov WORD [A20_OK], 0 - jmp .A20_end -.A20_on: - mov BYTE [A20_OK], 1 -.A20_end: - - ;; INITIALIZE PROTECTED MODE SEGMENT REGISTERS - mov ax, DATA_SELECTOR-GDT64 - mov ds, ax - mov es, ax - mov fs, ax - mov gs, ax - mov ss, ax - - ;; ACTIVATE PHYSICAL ADRESS EXTENSION - mov eax, cr4 - or eax, 100000b ; PAE = 1 = 4 Mo / page. 0 = 4 Ko - mov cr4, eax - - ;;cleanup - mov edi, 0x70000 - mov ecx, 0x10000 - xor eax, eax - rep stosd - ;;formatting - mov dword [0x70000], 0x71000 + 7 ; first PDP table - mov dword [0x71000], 0x72000 + 7 ; first page directory - mov dword [0x72000], 0x73000 + 7 ; first page table - mov edi, 0x73000 ; address of first page table - mov eax, 7 - mov ecx, 256 ; number of pages to map (1 MB) -.make_page_entries: - stosd - add edi, 4 - add eax, 0x1000 - loop .make_page_entries - ;; pointing pml4 - mov eax, 0x70000 ; Bass address of PML4 - mov cr3, eax ; load page-map level-4 base - - ;; ACTIVATE LONG MODE - mov ecx, 0xC0000080 ; address of MSR - rdmsr ; read MSR - or eax, 100000000b ; LME = 1. (Long Mode Enable) - wrmsr ; write MSR - - ;; ACTIVATE PAGING - mov eax, cr0 - or eax, 0x80000000 ; make bit 31 (PG = Paging) to 1 : - ; |1|000000000000000000000000000000 - ; | - ; `------ Paging bit - mov cr0, eax - push dword 0 - push dword [VIDEO_MODE] - push dword 0 - push dword [VGA_HEIGHT] - jmp (LONG_SELECTOR-GDT64):main64 - -[BITS 64] - -%include "boot/loader64.inc" - -;; DATA -Init db "Booting OS/K !", 0x0D, 0x0A, 0x0D, 0x0A, 0x09, " Checking CPUID...",0 -CPUIDD db 0x09, " Checking CPUID...", 0 -EnA20 db 0x09, " Enabling A20 line...", 0 -ReadAttempt db 0x09, " Attempt to read a sector with ATA commands...", 0x0A, 0x0D, 0x0A, 0x0D,0 -txt db 0x09, " Switching to Long Mode... ", 0 -Reinit db "Booting OS/K !", 0x0D, 0x0A, 0x0D, 0x0A, 0 -Pass db " OK", 0x0A, 0x0D, 0 -Fail db " FAIL!", 0x0A, 0x0D, 0 -msg db "The system is now in x64 mode. Is this not beautiful ?", 0x0A, 0x0D, 0 - -NoLongMode db 0x0A, 0x0D, "ERROR : Your computer is not designed for x64 OS", 0 -FileNotFound db "Second Stage Error : The Kernel was not found.", 0x0A, 0x0D, 0 -DiskError db "Second Stage Error : The Disk has crashed.", 0x0A, 0x0D, 0 - -filename db "KERNEL BIN" - -Bootdrv db 0 -UserData dw 0 -VGA_HEIGHT dq 0 -VIDEO_MODE dw 0 -VIDEO_MODE32 dw 0 -VGA_HEIGHT32 dw 0 -NextTRAM dq 0x0B8000 ; Last position of cursor -VIDEO_MODE64 dq 0 -VGA_HEIGHT64 dq 0 -VGA_X dq 0 -A20_OK db 0 - -main64: - pop qword [VGA_HEIGHT64] - pop qword [VIDEO_MODE64] - ;; INITIALIZE STACK - mov rsp, 0x9F000 - - call clear - - ;; Printing - mov bl, 0x0B - mov esi, Reinit - call write - - mov bl, 0x0F - mov esi, CPUIDD - call write - - mov bl, 0x0A - mov esi, Pass - call write - - mov bl, 0x0F - mov esi, EnA20 - call write - - cmp BYTE [A20_OK], 1 - je .A20Success - mov bl, 0x0C - mov esi, Fail - call write - jmp Die -.A20Success: - mov bl, 0x0A - mov esi, Pass - call write - - mov bl, 0x0F - mov esi, txt - call write - - mov bl, 0x0A - mov esi, Pass - call write - - mov bl, 0x0D - mov esi, msg - call write - - mov bl, 0x0F - mov esi, ReadAttempt - call write - - mov rcx, 2 -.looping: - nop - nop - nop - loop .looping ; Temporized because the ATA drive must be ready - - call ata_read - - jmp Die - - ; times 1024 nop - ; XXX ; - ; It seems impossible to have an executable > 2.0 kB... diff --git a/boot/loader16.inc b/boot/loader16.inc deleted file mode 100644 index a30cff9..0000000 --- a/boot/loader16.inc +++ /dev/null @@ -1,89 +0,0 @@ -;=----------------------------------------------------------------------------=; -; GNU GPL OS/K ; -; ; -; Authors: spectral` ; -; NeoX ; -; ; -; Desc: Kernel (second stage) Loader for OS/K INCLUDED FUNCTIONS ; -; (x86_64 architecture only) ; -;=----------------------------------------------------------------------------=; - -[BITS 16] - -disable_cursor: - pushf - push eax - push edx - mov dx, 0x3D4 - mov al, 0xA ; low cursor shape register - out dx, al - inc dx - mov al, 0x20 ; bits 6-7 unused, bit 5 disables the cursor, bits 0-4 control the cursor shape - out dx, al - pop edx - pop eax - popf - ret - -get_dimensions: - push eax - push ebx - mov ah, 0x0F - int 0x10 - mov [VGA_HEIGHT], ah - mov [VIDEO_MODE], al - pop ebx - pop eax - ret - -Is64bits: -;-----------------------------------------------------------------------; -; Checks if the CPU is compatible with 64-bits operating systems ; -; If the 21th bit of the eax register is set, then CPUID is supported ; -; We then test CPUID's result to see if long mode is supported ; -;-----------------------------------------------------------------------; - pushfd ; recovering the flags in eax - pop eax - mov ecx, eax - xor eax, 0x200000 - push eax - popfd - pushfd - pop eax - xor eax, ecx - shr eax, 21 - and eax, 1 ; magical spell of murta - push ecx - popfd - test eax, eax - jz .NonCompat ; if (CPUID non supporté) goto NonCompat - mov eax, 0x80000000 - cpuid - cmp eax, 0x80000001 - jb .NonCompat ; if (eax <= 0x80000001) goto NonCompat - mov eax, 0x80000001 - cpuid - test edx, 1 << 29 - jz .NonCompat ; if (edx != 1 << 29) goto NonCompat - ret ; back to mbr.s -.NonCompat: - stc - ret - -PrintB: -;---------------------------------------------------; -; 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 PrintB ; Loop untill string is null - .done: - ret diff --git a/boot/loader64.inc b/boot/loader64.inc deleted file mode 100644 index d3a51fa..0000000 --- a/boot/loader64.inc +++ /dev/null @@ -1,200 +0,0 @@ -;=----------------------------------------------------------------------------=; -; GNU GPL OS/K ; -; ; -; Authors: spectral` ; -; NeoX ; -; ; -; Desc: Kernel (second stage) Loader for OS/K INCLUDED FUNCTIONS ; -; (x86_64 architecture only) ; -;=----------------------------------------------------------------------------=; - -[BITS 64] - -clear: -;-----------------------------------------------------------------------; -; x64/LM Clear Text Screen Function ; -;-----------------------------------------------------------------------; - mov qword [NextTRAM], TRAM - mov edi, TRAM - push rsi - push rdi - push rcx - mov ah, 0 - mov al, 0 - mov rcx, 0x4000 ; traditionnal value - rep stosw ; fill screen with al while cx > 0 - pop rcx - pop rsi - pop rdi - ret - -write: -;-----------------------------------------------------------------------; -; x64/LM Text Printing Functions ; -; bl : color code ; -; esi : string address ; -;-----------------------------------------------------------------------; - mov edi, [NextTRAM] ; TRAM ADDRESS - push rsi - push rdi -.pLoop: - lodsb - cmp al, 0 ; while @al, i.e. while we're not hitting '\0' - je .pEnd - cmp al, 0x0A ; LF - je .lf - cmp al, 0x0D ; CR - je .cr - stosb ; text subpixel - mov al, bl - stosb ; color subpixel - add qword [NextTRAM], 0x2 ; Cursor moving - add qword [VGA_X], 0x2 ; coord + 2 because 2 subpixels - jmp .pLoop -.pEnd: - pop rdi - pop rsi - ret -.lf: - mov rax, [VGA_HEIGHT64] - add [NextTRAM], rax ; Cursor moving - add [NextTRAM], rax - add edi, eax ; Address moving - add edi, eax - jmp .pLoop -.cr: - push rax - mov rax, qword [VGA_X] - sub qword [NextTRAM], rax ; pos = X + Y * VGA_HEIGHT64. Donc pos - X = début de ligne - sub edi, edx - mov qword [VGA_X], 0 - pop rax - jmp .pLoop -.scroll: - ; XXX I don't think I'll implement this, but never know...; - jmp .pLoop - -dump: -;-----------------------------------------------------------------------; -; x64/LM Dump Printing Functions ; -; bl : color code ; -; esi : string address ; -;-----------------------------------------------------------------------; - mov edi, [NextTRAM] ; TRAM ADDRESS - push rsi - push rdi - push rcx - mov rcx, 512 -.pLoop: - lodsb - stosb ; text subpixel - mov al, bl - stosb ; color subpixel - add qword [NextTRAM], 0x2 ; Cursor moving - add qword [VGA_X], 0x2 ; coord + 2 because 2 subpixels - loop .pLoop - pop rcx - pop rdi - pop rsi - ret - -ata_read: -;-----------------------------------------------------------------------; -; x64/LM ATA Reading function ; -; ; -; ; -;-----------------------------------------------------------------------; - -; Technical infos about the ports (Intel Doc): -; -; Port Access Mode Misc -; -; 1f0 r/w Data register, the bytes of the disk itself -; 1f1 r Error register that can be handled -; 1f2 r/w Sector count, how many sectors to read -; 1f3 r/w Sector number, the actual sector wanted -; 1f4 r/w Cylinder low, cylinders is 0-1024 -; 1f5 r/w Cylinder high, this makes up the rest of the 1024 -; 1f6 r/w Drive/head -; bit 7 = 1 -; bit 6 = 0 -; bit 5 = 1 -; bit 4 = 0 drive 0 select -; = 1 drive 1 select -; bit 3-0 head select bits -; 1f7 r Status register -; bit 7 = 1 controller is executing a command -; bit 6 = 1 drive is ready -; bit 5 = 1 write fault -; bit 4 = 1 seek complete -; bit 3 = 1 sector buffer requires servicing -; bit 2 = 1 disk data read corrected -; bit 1 = 1 index - set to 1 each revolution -; bit 0 = 1 previous command ended in an error -; 1f7 w Command register -; commands: -; 50h format track -; 20h read sectors with retry -; 21h read sectors without retry -; 22h read long with retry -; 23h read long without retry -; 30h write sectors with retry -; 31h write sectors without retry -; 32h write long with retry -; 33h write long without retry -; - - push rax - push rbx - push rdx - push rcx - push rdi - mov dx, 0x1f6 ;Drive and head port - mov al, 0x0a0 ;Drive 0, head 0 - out dx,al - - mov dx, 0x1f2 ;Sector count port - mov al, 1 ;Read one sector - out dx, al - - mov dx, 0x1f3 ;Sector number port - mov al, 1 ;Read sector one - out dx, al - - mov dx, 0x1f4 ;Cylinder low port - mov al, 0 ;Cylinder 0 - out dx, al - - mov dx, 0x1f5 ;Cylinder high port - mov al, 0 ;The rest of the cylinder 0 - out dx, al - - mov dx, 0x1f7 ;Command port - mov al, 0x20 ;Read with retry. - out dx, al -still_going: - in al, dx - test al, 8 ;This means the sector buffer requires - ;servicing. - jz still_going ;Don't continue until the sector buffer - ;is ready. - - mov cx, 512/2 ;One sector /2 - mov rdi, buffer - mov dx, 0x1f0 ;Data port - data comes in and out of here. - rep insw - pop rdi - pop rcx - pop rdx - pop rbx - pop rax - mov bl, 0x0F - mov esi, buffer - call dump - mov bl, 0x0A - mov esi, end - call write - ret - - buffer: times 512 db "_" - end: db "[End of Sector]", 0x0 diff --git a/boot/mbr.asm b/boot/mbr.asm deleted file mode 100644 index f7a3066..0000000 --- a/boot/mbr.asm +++ /dev/null @@ -1,175 +0,0 @@ -;=----------------------------------------------------------------------------=; -; GNU GPL OS/K ; -; ; -; Authors: spectral` ; -; NeoX ; -; ; -; Desc: Bootsector for OS/K ; -; (x86_64 architecture only) ; -;=----------------------------------------------------------------------------=; - -;; BOOT "SEGMENT" -%define BOOT_SEG 0x07c0 ; (BOOT_SEG << 4) + BOOT_OFF = 0x007c00 -%define BOOT_OFF 0x0000 - -;; STACK "SEGMENT" -%define STACK_SEG 0x0600 ; (STACK_SEG << 4) + STACK_OFF = 0x007000 -%define STACK_OFF 0x1000 - -;; DISK BUFFER "SEGMENT" -%define BUFFER_SEG 0x2000 ; (BUFFER_SEG << 4) + BUFFER_OFF = 0x020000 -%define BUFFER_OFF 0x0000 - -;; SECOND STAGE LOADER "SEGMENT" -%define LOAD_SEG 0x0000 ; (LOAD_SEG << 4) + LOAD_OFF = 0x001000 -%define LOAD_OFF 0x1000 - -[BITS 16] ; Ensure 16-bit code (because fuck UEFI) - -Intro: - - jmp short _start ; Jump over the BIOS PARAMETER BLOCK - nop ; Required by BIOS to recognize the Disk loul -BPB: - ;---------------------------------------------------; - ; Disk description table ; - ;---------------------------------------------------; - %define OEMName bp+0x03 ; Disk label - %define bytesPerSector bp+0x0b ; Bytes per sector - %define sectorsPerCluster bp+0x0d ; Sectors per cluster - %define reservedSectors bp+0x0e ; Reserved sectors - %define fats bp+0x10 ; Number of fats - %define rootDirEntries bp+0x11 ; Number of entries in root dir - %define sectors bp+0x13 ; Logical sectors - %define mediaType bp+0x15 ; Media descriptor byte - %define fatSectors bp+0x16 ; Sectors per FAT - %define sectorsPerTrack bp+0x18 ; Sectors per track - %define heads bp+0x1a ; Number of sides/heads - %define hiddenSectors bp+0x1c ; Hidden sectors - %define hugeSectors bp+0x20 ; LBA sectors - %define biosBootdrvNum bp+0x24 ; Bootdrv number - %define reserved bp+0x25 ; This is not used - %define bootSignature bp+0x26 ; Bootdrv signature - %define volumeId bp+0x27 ; Volume ID - %define volumeLabel bp+0x2b ; Volume Label - %define fatTypeLabel bp+0x36 ; File system type - - times 0x3b db 0x00 ; ALLOCATE THE SECTORS FOR THE BPB - -;; ENTRY POINT -_start: - jmp BOOT_SEG:$+5 ; Fix the cs:ip registers with a vaudou magical trip - -bootstrap: - jmp go - -;; LOVELY DATA -FileNotFound db "First Stage ERROR : NO LOADER", 0 -DiskError db "First Stage ERROR : DISK", 0 -UserData dw 0 -Bootdrv db 0 -filename db "LOADER BIN" - - -;; GO ! -go: - mov ax, BOOT_SEG ; Set segments to the location of the bootloader - mov ds, ax - mov es, ax - - ;; INIT STACK - cli - mov ax, STACK_SEG ; Init the stack - mov ss, ax ; Continue init the stack - mov sp, STACK_OFF ; Ok man, the stack is in 4K :O - sti - mov bp, (0x7c0-STACK_SEG) << 4 ; Correct bp (the disk description table) - - ;; INITIALIZE BOOT DISK - or dl, dl ; Verifying dl points actually to the boot drive - jz load_root - mov byte [Bootdrv], dl ; Another soul (the disk) saved! - mov ah, 0x08 - int 0x13 ; int 0x13 : read drive parameters/geom - jc load_root - and cx, 0x003f ; Maximum sector number is the high bits 6-7 of cl - mov word [sectorsPerTrack], cx ; And whose low 8 bits are in ch - mov dl, dh ; Convert the maximum head number to a word with another vaudou magical trip - xor dh, dh - inc dx ; because head numbers start at zero - mov word [heads], dx ; Another soul (the heads number) saved! - - - ;; LOAD THE ROOT DIRECTORY FROM DISK -load_root: - xor cx, cx - mov ax, 32 ; Size of root dir = (rootDirEntries * 32) / bytesPerSector - mul word [rootDirEntries] ; multiply by the total size of the root directory - div word [bytesPerSector] ; divide by the number of bytes used per sector - xchg cx, ax - - mov al, byte [fats] ; Location of root dir = (fats * fatSectors) + reservedSectors - mul word [fatSectors] ; multiply by the sectors used - add ax, word [reservedSectors] ; increase ax by the reserved sectors - mov word [UserData], ax ; Start of user data = startOfRoot + numberOfRoot - add word [UserData], cx ; Add the size and location of the root directory - - mov di, BUFFER_SEG ; Set the extra segment to the disk buffer - mov es, di - mov di, BUFFER_OFF ; Set es:di and load the root directory into the disk buffer - call read_sectors ; Read the sectors - - ;; FIND THE SECOND STAGE LOADER - mov di, BUFFER_OFF ; Set es:di to the disk buffer - mov cx, word [rootDirEntries] ; Search through all of the root dir entries - xor ax, ax ; Clear ax for the file entry offset -search_root: - xchg cx, dx ; Save cx because it's a loop counter - mov si, filename ; Load the filename - mov cx, 11 ; Compare first 11 bytes - rep cmpsb ; Compare si and di cx times - je load_fat ; We found the loader - add ax, 32 ; File entry offset - mov di, BUFFER_OFF ; Point back to the start of the entry - add di, ax ; Add the offset to point to the next entry - xchg dx, cx - loop search_root ; Continue to search for the file - - ;; ERROR... - mov si, FileNotFound ; Could not find the file - call print - call reboot - - ;; LOAD THE FAT FROM THE FILE -load_fat: - mov ax, word [es:di + 15] ; Get the file cluster at offset 26 - push ax ; Store the FAT cluster - xor ax, ax ; Size of fat = (fats * fatSectors) - mov al, byte [fats] ; Move number of fats into al - mul word [fatSectors] ; Move fat sectors into bx - mov cx, ax ; Store in cx - mov ax, word [reservedSectors] ; Convert the first fat on the disk - mov di, BUFFER_OFF ; Set es:di and load the fat sectors into the disk buffer - call read_sectors ; Read the sectors - - ;; LOAD THE CLUSTERS OF THE LOADER AND JUMP - mov di, LOAD_SEG - mov es, di ; Set es:bx to where the file will load - mov di, LOAD_OFF - pop ax ; File cluster restored - call read_clusters ; Read clusters from the file - mov dl, byte [Bootdrv] ; Pass the boot Bootdrv into dl - jmp LOAD_SEG:LOAD_OFF ; Jump to the file loaded! - - hlt ; This should never be hit... - ; ... - ; ... - ; I hope.... - ; ... - call reboot - -%include "boot/mbr.inc" - -;; END - times 510 - ($ - $$) db 0 ; Pad remainder of boot sector with zeros - dw 0xaa55 ; Boot signature diff --git a/boot/mbr.inc b/boot/mbr.inc deleted file mode 100644 index dc11db1..0000000 --- a/boot/mbr.inc +++ /dev/null @@ -1,161 +0,0 @@ -;=----------------------------------------------------------------------------=; -; GNU GPL OS/K ; -; ; -; Authors: spectral` ; -; NeoX ; -; ; -; Desc: Bootsector for OS/K INCLUDED FUNCTIONS ; -; (x86_64 architecture only) ; -;=----------------------------------------------------------------------------=; -[BITS 16] - -read_clusters: -;---------------------------------------------------; -; Read file clusters, starting at the given cluster,; -; expects FAT to be loaded into the disk buffer. ; -; Please note that this may allocate up to 128KB ; -; of ram. ; -; ; -; Expects: AX = Starting cluster ; -; ES:DI = Location to load clusters ; -; ; -; Returns: None ; -; ; -;---------------------------------------------------; - pusha - push es - .cluster_loop: - xor bh, bh - xor dx, dx - push ax ; Get the cluster start = (cluster - 2) * sectorsPerCluster + UserData - sub ax, 2 ; Subtract 2 - mov bl, byte [sectorsPerCluster] ; Sectors per cluster is a byte value - mul bx ; multiply (cluster - 2) * sectorsPerCluster - add ax, word [UserData] ; add the UserData - xor ch, ch - mov cl, byte [sectorsPerCluster] ; Sectors to read - call read_sectors ; Read the sectors - pop ax ; Current cluster number - xor dx, dx - ;; 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, 21 ; Try five times to read the sector because i love 21 - .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 - -reboot: - xor ax, ax - int 0x16 ; Get a single keypress - mov ah, 0x0e ; Teletype output - mov al, 0x0d ; Carriage return - int 0x10 ; Video interupt - mov al, 0x0a ; Line feed - int 0x10 ; Video interupt - mov al, 0x0a ; Line feed - int 0x10 ; Video interupt - xor ax, ax - int 0x19 ; Reboot the system diff --git a/build/bin/disk.img b/build/bin/disk.img index e4692fd..51ab1ef 100644 Binary files a/build/bin/disk.img and b/build/bin/disk.img differ diff --git a/build/bin/loader.bin b/build/bin/loader.bin index 096e80a..39723e4 100644 Binary files a/build/bin/loader.bin and b/build/bin/loader.bin differ diff --git a/build/obj/boot/loader.bin b/build/obj/boot/loader.bin index 096e80a..39723e4 100644 Binary files a/build/obj/boot/loader.bin and b/build/obj/boot/loader.bin differ