1 files changed, 91 insertions, 0 deletions
diff --git a/kernel/src/boot/tag.c b/kernel/src/boot/tag.c
new file mode 100644
index 0000000..22ea758
--- /dev/null
+++ b/kernel/src/boot/tag.c
@@ -0,0 +1,91 @@
+#include <panic.h>
+#include <string.h>
+
+#include "print.h"
+#include "tag.h"
+#include "acpi/acpi.h"
+#include "graphics/framebuffer.h"
+#include "memory/memory.h"
+
+static struct BootInfo info;
+
+static void read_cmdline(struct BootTag *tag, char *data, uint8_t len) {
+    debugk("Found cmdline");
+    if (len >= CMDLINE_MAX) 
+        panic("multiboot2 cmd line to long\nmax is %d but was provided %d\n",
+              CMDLINE_MAX, len);
+    memcpy(tag->data.cmdline, data, len);
+    info.tags[ID_CMDLINE] = *tag;
+}
+
+static void read_framebuffer(struct BootTag *tag, uint32_t *data) {
+    debugk("Found framebuffer");
+    tag->data.framebuffer = (struct Framebuffer *) data;
+    info.tags[ID_FRAMEBUFFER] = *tag;;
+}
+
+static void read_memorymap(struct BootTag *tag, uint32_t *data) {
+    debugk("Found memorymap");
+    tag->data.memory_map = (struct MemoryMap *) data;
+    info.tags[iD_MEMORYMAP] = *tag;
+}
+
+static void read_rsdp(struct BootTag *tag, char *data) {
+    debugk("Found RSDP");
+    tag->data.rsdp = (struct RootSystemDescriptionPointer *) data;
+    info.tags[ID_RSDP] = *tag;
+}
+
+static uint32_t *read_tag(uint32_t *data) {
+    struct BootTag tag;
+    tag.type = ((uint16_t*)data)[0];
+    tag.size = data[1];
+    tag.valid = 1;
+
+    uint8_t data_len = tag.size - 2 * sizeof(uint32_t);
+
+    switch (tag.type) {
+        case ID_CMDLINE:
+            read_cmdline(&tag, (char *)(data + 2), data_len);
+            break;
+        case ID_FRAMEBUFFER:
+            read_framebuffer(&tag, data + 2);
+            break;
+        case iD_MEMORYMAP:
+            read_memorymap(&tag, data + 2);
+            break;
+        case ID_RSDP:
+            read_rsdp(&tag, (char *) (data + 2));
+            break;
+        default:
+            break;
+    }
+
+    if(tag.size % 8 != 0) {
+		tag.size += 8 - (tag.size % 8);
+	}
+
+    return data + tag.size / sizeof(uint32_t);
+}
+
+void load_boot_info(void* boot_info) {
+
+    debugk("Reading multiboot info");
+
+    memset(&info, 0, sizeof(boot_info));
+
+    uint32_t* data = (uint32_t*) boot_info;
+    info.total_size = *data++;
+    info.reserved = *data++;
+
+    while((uint8_t*) data < (uint8_t*) boot_info + info.total_size) {
+        data = read_tag(data);
+    }
+
+    succek("Loaded multiboot info");
+}
+
+bool get_boot_tag(enum BootTagID id, struct BootTag **tag) {
+    *tag = &info.tags[id];
+    return (*tag)->valid;
+}