Init

6 files changed, 120 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..44984ee
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,7 @@
+/limine-binary
+/limine-binary.tar.gz
+/edk2-ovmf-bins
+/edk2-ovmf-bins.tar.gz
+/iso_root
+*.iso
+*.hdd
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..9779670
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,37 @@
+.DEFAULT_GOAL := macaroni.iso
+
+LIMINE_SHARE = /opt/homebrew/share/limine/
+
+BUILD_OUT = build
+ASM       = nasm
+ASM_FLAGS = -felf32
+CFLAG     = -std=c11 -ffreestanding -O0 -Wall -Wextra
+CC        = i686-elf-gcc 
+BINFLAG   = -T linker.ld -ffreestanding -O0 -nostdlib -lgcc
+
+boot.o: src/boot.asm
+	${ASM} ${ASM_FLAGS} src/boot.asm -o ${BUILD_OUT}/boot.o
+
+kernel.o: src/kernel.c
+	${CC} -c src/kernel.c -o ${BUILD_OUT}/kernel.o ${CFLAG}
+
+macaroni.bin: boot.o kernel.o
+	${CC} -o ${BUILD_OUT}/macaroni.bin ${BINFLAG} ${BUILD_OUT}/*.o
+
+macaroni.iso: macaroni.bin
+	mkdir -p ${BUILD_OUT}/iso
+	cp ${BUILD_OUT}/macaroni.bin ${BUILD_OUT}/iso/macaroni.bin
+	printf "timeout: 0\n/macaroni\n    protocol: multiboot1\n    kernel_path: boot():/macaroni.bin\n" > ${BUILD_OUT}/iso/limine.conf
+	cp ${LIMINE_SHARE}/limine-bios-cd.bin ${LIMINE_SHARE}/limine-bios.sys ${LIMINE_SHARE}/limine-uefi-cd.bin ${BUILD_OUT}/iso/
+	xorriso -as mkisofs -R -r -J -b limine-bios-cd.bin -no-emul-boot -boot-load-size 4 -boot-info-table \
+		--efi-boot limine-uefi-cd.bin -efi-boot-part --efi-boot-image --protective-msdos-label \
+		${BUILD_OUT}/iso -o ${BUILD_OUT}/macaroni.iso
+	limine bios-install ${BUILD_OUT}/macaroni.iso
+
+.PHONY: demo
+demo: macaroni.iso
+	qemu-system-x86_64 -cdrom ${BUILD_OUT}/macaroni.iso
+
+.PHONY: clean
+clean:
+	rm -rf ${BUILD_OUT}/**
diff --git a/build/.gitkeep b/build/.gitkeep
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/build/.gitkeep
diff --git a/linker.ld b/linker.ld
new file mode 100644
index 0000000..29da3f9
--- /dev/null
+++ b/linker.ld
@@ -0,0 +1,9 @@
+ENTRY(_start)
+SECTIONS
+{
+    . = 2M;
+    .text   BLOCK(4K) : ALIGN(4K) { *(.multiboot_header) *(.text) }
+    .rodata BLOCK(4K) : ALIGN(4K) { *(.rodata) }
+    .data   BLOCK(4K) : ALIGN(4K) { *(.data) }
+    .bss    BLOCK(4K) : ALIGN(4K) { *(COMMON) *(.bss) }
+}
diff --git a/src/boot.asm b/src/boot.asm
new file mode 100644
index 0000000..cbf57d6
--- /dev/null
+++ b/src/boot.asm
@@ -0,0 +1,31 @@
+;> The Multiboot header must be contained completely within the first 8192 bytes of the OS 
+;> image, and must be longword (32-bit) aligned.
+MULTIBOOT_ALIGN_TO_PAGE:   equ 1 << 0
+MULTIBOOT_MEMORY_DESCRIBE: equ 1 << 2
+MULTIBOOT_MAGIC:           equ 0x1BADB002
+MULTIBOOT_FLAGS:           equ (MULTIBOOT_ALIGN_TO_PAGE | MULTIBOOT_MEMORY_DESCRIBE)
+MULTIBOOT_CHECKSUM:        equ -(MULTIBOOT_MAGIC + MULTIBOOT_FLAGS)
+section .multiboot_header
+align 4
+    dd MULTIBOOT_MAGIC
+    dd MULTIBOOT_FLAGS
+    dd MULTIBOOT_CHECKSUM
+
+STACK_SIZE: equ (1 << 14)
+section .bss
+align 16
+stack_bottom:
+    resb STACK_SIZE
+stack_top:
+
+section .text
+global _start:function (_start.end - _start)
+_start:
+    mov esp, stack_top
+    extern cmain
+    call cmain
+    cli
+
+jmp $
+
+.end:
diff --git a/src/kernel.c b/src/kernel.c
new file mode 100644
index 0000000..1459f73
--- /dev/null
+++ b/src/kernel.c
@@ -0,0 +1,36 @@
+#include <stddef.h>
+#include <stdint.h>
+
+#define WIDTH 80
+#define HEIGHT 25
+
+#define BLACK 0
+#define BLUE 1
+#define GREEN 2
+#define RED 4
+#define MAGENTA 13
+#define WHITE 15
+
+int strlen(char* s) {
+  int n = 0;
+  char* s_ptr = s;
+  while (*(s_ptr++)) { 
+    n++;
+  }
+  return n;
+}
+
+void cmain(void) {
+  uint16_t* vgamem = (uint16_t*) 0xB8000;
+  uint16_t vgacolors[6] = {WHITE | RED << 4, WHITE | GREEN << 4, WHITE | BLUE << 4, BLACK | RED << 4, BLACK | GREEN << 4, BLACK | BLUE << 4};
+  char* s = "Hello world!";
+  int i,j,k;
+  for (k = 0; k >= 0; ++k) {
+    k = (k % 5);
+    j = 0;
+    while (j < 100000000) { j++; } // Since we don't have an interrupt descriptor table we can't use the PIC; this emulates "sleeping"
+    for (i = 0; i < WIDTH*HEIGHT; i++) {
+      vgamem[i] = s[i % strlen(s)] | vgacolors[(i+k) % 6] << 8;
+    }
+  }
+}
\ No newline at end of file