arch: i386: add multiboot support

Add support for the multiboot specification. These files will allow the
kernel to read the multiboot header information as well as the provided
memory map.

Signed-off-by: Danny Holman <dholman@gymli.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/arch/i386/kernel/multiboot.c b/arch/i386/kernel/multiboot.c
new file mode 100644
index 0000000..d7f0a65
--- /dev/null
+++ b/arch/i386/kernel/multiboot.c
@@ -0,0 +1,23 @@
+#include <kernel/multiboot.h>
+#include <kernel/tty.h>
+#include <kernel/panic.h>
+#include <kernel/io.h>
+
+void i386_entry(uint32_t mboot_magic, struct mboot_info *header) {
+        paging_init();
+        tty_init();
+
+        struct mboot_info *vheader = get_vaddr(header);
+        mark_bitmap(header, 1);
+        map_page(header, vheader, 0x003);
+
+        if (mboot_magic != MBOOT_LOADER_MAGIC)
+                panic("NOT BOOTED WITH MULTIBOOT BOOTLOADER");
+        if (!(vheader->flags >> 6 & 0x1))
+                panic("NO MEMORY MAP FROM BOOTLOADER");
+
+        gdt_install();
+        idt_install();
+        alloc_init(vheader);
+        kernel_main(vheader->cmdline);
+}