add mbinfo module to parse multiboot2 boot info

src/hos_main.c

@@ -1,33 +1,8 @@
 #include <stdint.h>
 #include "fb.h"
+#include "mbinfo.h"
 
-static uint32_t * process_mbinfo_tag(uint32_t * mbinfo)
+void hos_main(uint32_t mbinfo_addr)
 {
-    uint32_t type = mbinfo[0];
+    mbinfo_init(mbinfo_addr);
-    uint32_t size = mbinfo[1];
-    switch (type)
-    {
-    case 0u:
-        return 0u;
-
-    case 8u:
-        fb_init((uint32_t *)mbinfo[2], mbinfo[5], mbinfo[6], mbinfo[4]);
-        break;
-    }
-    return (uint32_t *)(((uint32_t)mbinfo + size + 7u) & 0xFFFFFFF8u);
-}
-
-static void process_mbinfo(uint32_t * mbinfo)
-{
-    /* Skip multiboot2 boot information header. */
-    mbinfo += 2u;
-    do
-    {
-        mbinfo = process_mbinfo_tag(mbinfo);
-    } while (mbinfo != (uint32_t *)0u);
-}
-
-void hos_main(uint32_t * mbinfo)
-{
-    process_mbinfo(mbinfo);
 }

src/mbinfo.c

@@ -0,0 +1,29 @@
+#include "multiboot2.h"
+#include "fb.h"
+
+static void mbinfo_process_tag(multiboot2_info_tag_t * tag)
+{
+    switch (tag->type)
+    {
+    case MULTIBOOT2_INFO_FRAMEBUFFER_INFO:
+        {
+            multiboot2_info_framebuffer_info_t * fbinfo =
+                (multiboot2_info_framebuffer_info_t *)tag;
+            fb_init((uint32_t *)(uintptr_t)fbinfo->framebuffer_addr,
+                    fbinfo->framebuffer_width,
+                    fbinfo->framebuffer_height,
+                    fbinfo->framebuffer_pitch);
+        }
+        break;
+    }
+}
+
+void mbinfo_init(uint32_t mbinfo_addr)
+{
+    multiboot2_info_tag_t * tag = (multiboot2_info_tag_t *)(mbinfo_addr + sizeof(multiboot2_info_header_t));
+    while (tag->type != 0u)
+    {
+        mbinfo_process_tag(tag);
+        tag = multiboot2_info_next_tag(tag);
+    }
+}

src/mbinfo.h

@@ -0,0 +1,8 @@
+#ifndef MBINFO_H
+#define MBINFO_H
+
+#include <stdint.h>
+
+void mbinfo_init(uint32_t mbinfo_addr);
+
+#endif

src/multiboot2.h

@@ -34,4 +34,49 @@ typedef struct {
 #define multiboot2_framebuffer_tag(width, height, depth) \
     {{5u, 0u, 20u}, width, height, depth}
 
+#define MULTIBOOT2_INFO_TAG_ALIGNMENT 8u
+#define MULTIBOOT2_INFO_BOOT_COMMAND_LINE 1u
+#define MULTIBOOT2_INFO_BOOT_LOADER_NAME 2u
+#define MULTIBOOT2_INFO_MODULES 3u
+#define MULTIBOOT2_INFO_BASIC_MEMORY_INFO 4u
+#define MULTIBOOT2_INFO_BIOS_BOOT_DEVICE 5u
+#define MULTIBOOT2_INFO_MEMORY_MAP 6u
+#define MULTIBOOT2_INFO_VBE_INFO 7u
+#define MULTIBOOT2_INFO_FRAMEBUFFER_INFO 8u
+#define MULTIBOOT2_INFO_ELF_SYMBOLS 9u
+#define MULTIBOOT2_INFO_APM_TABLE 10u
+#define MULTIBOOT2_INFO_EFI_32BIT_SYSTEM_TABLE_POINTER 11u
+#define MULTIBOOT2_INFO_EFI_64BIT_SYSTEM_TABLE_POINTER 12u
+#define MULTIBOOT2_INFO_SMBIOS_TABLES 13u
+#define MULTIBOOT2_INFO_ACPI_OLD_RSDP 14u
+#define MULTIBOOT2_INFO_NETWORKING_INFO 16u
+#define MULTIBOOT2_INFO_EFI_MEMORY_MAP 17u
+#define MULTIBOOT2_INFO_EFI_BOOT_SERVICES_NOT_TERMINATED 18u
+#define MULTIBOOT2_INFO_EFI_32BIT_IMAGE_HANDLE_POINTER 19u
+#define MULTIBOOT2_INFO_EFI_64BIT_IMAGE_HANDLE_POINTER 20u
+#define MULTIBOOT2_INFO_IMAGE_LOAD_BASE_PHYSICAL_ADDRESS 21u
+
+typedef struct {
+    uint32_t total_size;
+    uint32_t _reserved;
+} multiboot2_info_header_t;
+
+typedef struct {
+    uint32_t type;
+    uint32_t size;
+} multiboot2_info_tag_t;
+#define multiboot2_info_next_tag(current_tag) \
+    (multiboot2_info_tag_t *)(((uintptr_t)current_tag + current_tag->size + MULTIBOOT2_INFO_TAG_ALIGNMENT - 1u) & ~(MULTIBOOT2_INFO_TAG_ALIGNMENT - 1u))
+
+typedef struct {
+    multiboot2_info_tag_t header;
+    uint64_t framebuffer_addr;
+    uint32_t framebuffer_pitch;
+    uint32_t framebuffer_width;
+    uint32_t framebuffer_height;
+    uint8_t framebuffer_bpp;
+    uint8_t framebuffer_type;
+    uint8_t _reserved;
+} multiboot2_info_framebuffer_info_t;
+
 #endif