Shell

.gitignore

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+src/Binaries

buildcrosscompiler.sh

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+# nasm and qemu
+sudo dnf install nasm
+sudo dnf install qemu
+sudo dnf install qemu-kvm
+
+# GCC cross compiler for i386 systems (might take quite some time, prepare food)
+
+sudo dnf update
+sudo dnf install gcc gcc-c++ make
+sudo dnf install bison
+sudo dnf install flex
+sudo dnf install libgmp3-devel
+sudo dnf install libmpc-devel
+sudo dnf install libmpfr-devel
+sudo dnf install texinfo
+
+#cURL (needed to clone some required files)
+sudo dnf install curl
+
+export PREFIX="/usr/local/i386elfgcc"
+export TARGET=i386-elf
+export PATH="$PREFIX/bin:$PATH"
+
+mkdir /tmp/src
+cd /tmp/src
+curl -O http://ftp.gnu.org/gnu/binutils/binutils-2.39.tar.gz
+tar xf binutils-2.39.tar.gz
+mkdir binutils-build
+cd binutils-build
+../binutils-2.39/configure --target=$TARGET --enable-interwork --enable-multilib --disable-nls --disable-werror --prefix=$PREFIX 2>&1 | tee configure.log
+sudo make all install 2>&1 | tee make.log
+
+cd /tmp/src
+curl -O https://ftp.gnu.org/gnu/gcc/gcc-12.2.0/gcc-12.2.0.tar.gz
+tar xf gcc-12.2.0.tar.gz
+mkdir gcc-build
+cd gcc-build
+echo Configure: . . . . . . .
+../gcc-12.2.0/configure --target=$TARGET --prefix="$PREFIX" --disable-nls --disable-libssp --enable-language=c,c++ --without-headers
+echo MAKE ALL-GCC:
+sudo make all-gcc
+echo MAKE ALL-TARGET-LIBGCC:
+sudo make all-target-libgcc
+echo MAKE INSTALL-GCC:
+sudo make install-gcc
+echo MAKE INSTALL-TARGET-LIBGCC:
+sudo make install-target-libgcc
+echo HERE U GO MAYBE:
+ls /usr/local/i386elfgcc/bin
+export PATH="$PATH:/usr/local/i386elfgcc/bin"

src/bootloader/boot.asm

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+[org 0x7c00]                        ; start of data segment
+KERNEL_LOCATION equ 0x1000
+
+
+mov [BOOT_DISK], dl                 
+
+
+xor ax, ax                           ;starting at 0x0
+mov es, ax
+mov ds, ax
+mov bp, 0x8000
+mov sp, bp
+
+mov bx, KERNEL_LOCATION ; we want to load the kwrnwl to the kernel location
+mov dh, 20 ;might have to change this number. number of sectors to read
+
+mov ah, 0x02
+mov al, dh  ; number of sectors
+mov ch, 0x00
+mov dh, 0x00
+mov cl, 0x02
+mov dl, [BOOT_DISK]
+int 0x13                ;load from disk
+
+                       ; error managment
+jc error               ; jump if carry flag is set
+cmp al, 2
+jne error
+
+jmp endload
+
+
+error: 
+    mov ah, 0x0e 
+    mov bx, errorMsg
+
+eloop:
+    mov al, [bx]
+    cmp al, 0
+    je endload
+    int 0x10
+    inc bx 
+    jmp eloop
+
+endload:
+
+mov ah, 0x0
+mov al, 0x3
+int 0x10                ; text mode
+
+
+CODE_SEG equ GDT_code - GDT_start
+DATA_SEG equ GDT_data - GDT_start
+
+cli
+lgdt [GDT_descriptor]
+mov eax, cr0
+or eax, 1
+mov cr0, eax
+jmp CODE_SEG:start_protected_mode
+
+jmp $
+
+errorMsg: 
+    db "error", 0 
+
+BOOT_DISK: db 0
+
+GDT_start:
+    GDT_null:
+        dd 0x0                         ; we get 4gb of memory in protected mode
+        dd 0x0                         ; flat memory model
+
+    GDT_code:
+        dw 0xffff                      ; we only define the first 16bits of the limit the real value is 0xfffff 
+        dw 0x0                         ; we multiply this value by 0x1000 as described in the flags
+        db 0x0
+        db 0b10011010                  
+        db 0b11001111                  ; the last 4 bits of the limit are described here 0b1111
+        db 0x0
+
+    GDT_data:
+        dw 0xffff
+        dw 0x0
+        db 0x0
+        db 0b10010010
+        db 0b11001111
+        db 0x0
+
+GDT_end:
+
+GDT_descriptor:
+    dw GDT_end - GDT_start - 1
+    dd GDT_start
+
+; need to refactor this file
+; load the idtp
+
+[bits 32]
+start_protected_mode:
+    mov ax, DATA_SEG ;segment registers ; the value is 16 
+	mov ds, ax ;data segment
+	mov ss, ax ;stack segment
+	mov es, ax ;extra segments
+	mov fs, ax
+	mov gs, ax
+
+	mov ebp, 0x90000		; 32 bit stack base pointer
+	mov esp, ebp
+
+    ; ; print digit    
+    ; mov ax, ax
+    ; mov ecx, 0xb8000 ;print digit
+    ; print_dec: 
+    ;     xor dx, dx
+    ;     mov bx, 10
+    ;     div bx ; remainder goes to dx
+
+    ;     xor ah, ah
+
+    ;     mov bl, dl
+    ;     add bl, 0x30
+    ;     mov bh, 0x07
+    ;     mov [ecx], bx    
+
+    ;     add ecx, 2
+    ;     cmp ax, 0
+    ;     jne print_dec
+
+
+    jmp KERNEL_LOCATION
+
+
+
+times 510-($-$$) db 0              
+dw 0xaa55

src/bootloader/kernel_entry.asm

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+section .text
+    [bits 32]
+    [extern _start]
+    call _start
+    jmp $

src/bootloader/zeroes.asm

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+times 10240 db 0