1 files changed, 79 insertions, 0 deletions
diff --git a/src/arch/x86/common/boot/multiboot.rs b/src/arch/x86/common/boot/multiboot.rs
new file mode 100644
index 0000000..09789ce
--- /dev/null
+++ b/src/arch/x86/common/boot/multiboot.rs
@@ -0,0 +1,79 @@
+pub const MULTIBOOT2_BOOTLOADER_MAGIC: u32 = 0x36d76289;
+pub const MULTIBOOT_TAG_TYPE_END: u32 = 0;
+pub const MULTIBOOT_TAG_TYPE_MMAP: u32 = 6;
+pub const MULTIBOOT_TAG_TYPE_FB: u32 = 8;
+
+use crate::{print, println};
+
+pub fn parse_fb_multiboot(mut mem: *mut u32) {
+    let framebuffer_addr: u64 = unsafe { *(mem as *mut u64) };
+    let framebuffer_pitch: u32 = unsafe { *mem.wrapping_add(2) };
+    let framebuffer_width: u32 = unsafe { *mem.wrapping_add(3) };
+    let framebuffer_height: u32 = unsafe { *mem.wrapping_add(4) };
+    let framebuffer_bpp: u8 = unsafe { *(mem.wrapping_add(5) as *mut u8) };
+    let framebuffer_type: u8 = unsafe { *(mem.wrapping_add(5) as *mut u8).wrapping_add(1) };
+    let reserved: u8 = unsafe { *(mem.wrapping_add(5) as *mut u8).wrapping_add(1) };
+
+    println!(
+        "0x{:x} {:x} {:x} {:x}",
+        framebuffer_addr, framebuffer_pitch, framebuffer_width, framebuffer_height
+    );
+}
+
+pub fn parse_mem_multiboot(mut mem: *mut u32, _size: u32) {
+    let mut curr_size: u32 = 16;
+
+    while curr_size < _size {
+        let base_addr: u64 = unsafe { *(mem as *mut u64) };
+        let length: u64 = unsafe { *(mem.wrapping_add(2) as *mut u64) };
+        let _type: u32 = unsafe { *mem.wrapping_add(4) };
+        let reserved: u32 = unsafe { *mem.wrapping_add(5) };
+        assert_eq!(reserved, 0, "reserved not 0");
+
+        //println!("{:x} {:x} {:x}", base_addr, length, _type);
+
+        mem = mem.wrapping_add(6);
+        curr_size += 24;
+    }
+}
+
+pub fn parse_multiboot(mut multiboot_bootinfo: *mut u32, multiboot_magic: u32) {
+    assert_eq!(
+        multiboot_magic, MULTIBOOT2_BOOTLOADER_MAGIC,
+        "MULTIBOOT2_BOOTLOADER_MAGIC"
+    );
+
+    let total_size: u32 = unsafe { *multiboot_bootinfo };
+    let mut size = 8;
+    multiboot_bootinfo = multiboot_bootinfo.wrapping_add(2);
+
+    while size < total_size {
+        let _type: u32 = unsafe { *multiboot_bootinfo };
+        let _size: u32 = unsafe { *(multiboot_bootinfo.wrapping_add(1)) };
+        let mem: *mut u32 = multiboot_bootinfo.wrapping_add(4);
+        let mem2: *mut u32 = multiboot_bootinfo.wrapping_add(2);
+
+        match _type {
+            MULTIBOOT_TAG_TYPE_FB => {
+                parse_fb_multiboot(mem2);
+            }
+            MULTIBOOT_TAG_TYPE_MMAP => {
+                parse_mem_multiboot(mem, _size);
+            }
+            _ => {}
+        }
+
+        let inc_size = (_size / 8 + (_size % 8 != 0) as u32) * 8;
+        size += inc_size;
+
+        println!("{} {} {}", _type, _size, inc_size);
+        multiboot_bootinfo = multiboot_bootinfo.wrapping_add((inc_size / 4).try_into().unwrap());
+
+        if _type == MULTIBOOT_TAG_TYPE_END {
+            assert_eq!(_size, 8, "MULTIBOOT_TAG_TYPE_END");
+            break;
+        }
+    }
+
+    assert_eq!(total_size, size, "Multiboot");
+}