Initial commit

5 files changed, 126 insertions, 0 deletions

diff --git a/build.bat b/build.bat
new file mode 100644
index 0000000..da1fbba
--- /dev/null
+++ b/build.bat
@@ -0,0 +1,29 @@
+IF EXIST build (
+    rmdir /s /q build
+)
+
+mkdir build
+
+:: bootloader
+nasm -g -O0 -f bin -o build/boot.bin src/boot.s
+
+:: kernel
+clang --target=x86_64-unknown-linux-gnu -c src/kernel.c -o build/kernel.o -std=c23 -ffreestanding -Wall -Wextra
+ld.lld -T linker.ld build/kernel.o -o build/kernel.bin
+
+:: create img
+copy ref.img build/disk.img
+:: qemu-img create -f raw build/disk.img 8M
+:: qemu-img dd if=build/boot.bin of=build/disk.img
+:: qemu-img dd count=2 skip=1 if=build/kernel.o of=build/disk.img
+
+:: -drive is equivalent to -hda
+:: bootloader
+::start qemu-system-x86_64 -drive file=build/boot.bin,index=0,media=disk,format=raw -s -S
+:: img with bootload
+start qemu-system-x86_64 -drive file=ref.img,index=0,media=disk,format=raw -s -S
+:: start qemu-system-x86_64 -drive file=fat:build/boot.bin,index=0,media=disk,format=raw -s -S
+
+:: start lldb --arch x86_64 -s dbgcmd
+
+:: start windbgx -v -kx exdi:PathToSrvCfgFiles=exdiConfigData.xml,CLSID={29f9906e-9dbe-4d4b-b0fb-6acf7fb6d014},Kd=Guess,DataBreaks=Exdi
diff --git a/dbgcmd b/dbgcmd
new file mode 100644
index 0000000..6054b7f
--- /dev/null
+++ b/dbgcmd
@@ -0,0 +1,4 @@
+settings set target.x86-disassembly-flavor intel
+gdb-remote localhost:1234
+b 0x7c00
+c
diff --git a/linker.ld b/linker.ld
new file mode 100644
index 0000000..03d3967
--- /dev/null
+++ b/linker.ld
@@ -0,0 +1,9 @@
+ENTRY(k_main)
+
+SECTIONS {
+    . = 2M;
+
+}
+
+OUTPUT_FORMAT(elf64-x86-64)
+OUTPUT(kernel.bin)
diff --git a/src/boot.s b/src/boot.s
new file mode 100644
index 0000000..28da384
--- /dev/null
+++ b/src/boot.s
@@ -0,0 +1,81 @@
+    mov ax, 0x7c0
+    mov ds, ax
+    mov ax, 0xb800 ; protected mode video memory segment (addr / 16)
+    mov es, ax
+    mov si, msg
+
+    cld
+
+    call print
+
+    cli
+
+; print using BIOS functions
+; print_loop:
+;     lodsb                   ; load byte from DS:SI into al
+;     or al, al
+;     jz hang
+;     mov ah, 0x0E
+;     int 0x10
+;     jmp print_loop
+
+; print without using BIOS functions
+print:
+    lodsb
+    cmp al, 0
+    jz exit_print
+
+    mov ah, 0x0F
+    mov cx, ax
+
+    movzx bx, byte [xpos]
+    shl bx, 1
+    movzx ax, byte [ypos]
+    mov dx, 160
+    mul dx
+
+    xor di, di
+    mov di, bx
+    add di, ax
+
+    mov ax, cx
+    stosw
+    add byte[xpos], 1
+    jmp print
+
+exit_print:
+    add byte[ypos], 1
+    mov byte[xpos], 0
+    ret
+
+hang:
+    jmp hang
+
+
+    ; vars
+    msg     db 'Hello world', 13, 10, 0 ; Hello world CR LF \0
+    xpos    db 0
+    ypos    db 0
+
+
+    ; fill
+    times 0x1b8 -($-$$) db 0    ; fill MBR boostrap
+    dd 0                        ; fill unique disk ID
+    dw 0                        ; reserved
+    ; write first partition table entry CHS for start and end are set to 0
+    db 0x80     ; mark the partition as bootable
+    db 0x0      ; partition start head
+    dw 0x0      ; partition start sector and cylinder (sector = 1, cylinder = 0)
+    db 0x06     ; system ID (partition type, 07 = exFAT)
+    db 0x0      ; partition end head
+    dw 0x0      ; partition end sector and cylinder (sector = 5, cylinder = 455)
+    dd 0x1      ; partition start LBA
+    dd 0x3fff   ; partition end LBA
+
+    times 0x10 db 0             ; fill second partition table entry
+    times 0x10 db 0             ; fill third partition table entry
+    times 0x10 db 0             ; fill fourth partition table entry
+    dw 0xAA55                   ; valid boot sector signature
+
+    ; db 'TEST'
+    ; times 0x800000 - ($-$$) db 0
diff --git a/src/kernel.c b/src/kernel.c
new file mode 100644
index 0000000..23d2c96
--- /dev/null
+++ b/src/kernel.c
@@ -0,0 +1,3 @@
+int k_main(void) {
+    return 0;
+}