...

src/boot/main.c

@@ -10,7 +10,7 @@
 #define MAX_REGIONS 64
 
 typedef struct {
-    u64 base_address;
+    u64 base_addr;
     u64 length;
 } memory_region;
 
@@ -20,8 +20,8 @@ extern uptr kernel_end;
 static memory_region memory_regions[MAX_REGIONS] = {0};
 static size_t memory_region_count = 0;
 
-static void find_memory_regions(uptr multiboot_info) {
-    multiboot_tag_mmap *tag = multiboot_get_mmap(multiboot_info);
+static void find_memory_regions() {
+    multiboot_tag_mmap *tag = multiboot_get_mmap();
     if (tag == NULL) {
         boot_panic("Multiboot did not provide mmap tag");
     }
@@ -37,7 +37,7 @@ static void find_memory_regions(uptr multiboot_info) {
                 boot_panic("Too many memory regions");
             }
 
-            memory_regions[memory_region_count++] = (memory_region){ entry->base_address, entry->length };
+            memory_regions[memory_region_count++] = (memory_region){ entry->base_addr, entry->length };
         }
 
         entry_ptr += tag->entry_size;
@@ -45,11 +45,11 @@ static void find_memory_regions(uptr multiboot_info) {
 }
 
 // We are now in long mode with kernel pages and vga buffer identity mapped
-void x86_64_main(uptr multiboot_info) {
+void x86_64_main() {
     console_clear();
-    find_memory_regions(multiboot_info);
+    find_memory_regions();
 
     for (u32 i = 0; i < memory_region_count; ++i) {
-        kprintf("region: base_address=0x%X, length=0x%X\n", memory_regions[i].base_address, memory_regions[i].length);
+        kprintf("region: base_addr=0x%X, length=0x%X\n", memory_regions[i].base_addr, memory_regions[i].length);
     }
 }

src/boot/multiboot2.c

@@ -1,12 +1,15 @@
 #include "multiboot2.h"
 
+// [size:4][reserved:4][data:N]
 #define INFO_DATA_OFFSET    8
-#define TAG_ALIGNMENT       8
+
 #define TAG_TYPE_OFFSET     0
 #define TAG_SIZE_OFFSET     4
 
-void *multiboot_get_tag(uptr multiboot_info, u32 type) {
-    uptr current = multiboot_info + INFO_DATA_OFFSET;
+extern u8 multiboot_info[];
+
+void *multiboot_get_tag(u32 type) {
+    uptr current = (uptr)&multiboot_info + INFO_DATA_OFFSET;
 
     while (true) {
         u32 tag_type = *(u32*)(current + TAG_TYPE_OFFSET);
@@ -20,7 +23,8 @@ void *multiboot_get_tag(uptr multiboot_info, u32 type) {
             return (void*)current;
         }
 
-        current = align_up(current + tag_size, TAG_ALIGNMENT);
+        // note(nub31): Each tag is aligned to 8 bytes
+        current = align_up(current + tag_size, 8);
     }
 
     return NULL;

src/boot/multiboot2.h

@@ -43,7 +43,7 @@
 #define MULTIBOOT_TAG_TYPE_EFI_BS 18
 #define MULTIBOOT_TAG_TYPE_EFI32_IH 19
 #define MULTIBOOT_TAG_TYPE_EFI64_IH 20
-#define MULTIBOOT_TAG_TYPE_LOAD_BASE_ADDRESS 21
+#define MULTIBOOT_TAG_TYPE_LOAD_BASE_ADDR 21
 
 typedef struct {
     u32 type;
@@ -87,7 +87,7 @@ typedef struct {
 #define MULTIBOOT_MEMORY_BADRAM 5
 
 typedef struct {
-    u64 base_address;
+    u64 base_addr;
     u64 length;
     u32 type;
     u32 reserved;
@@ -127,7 +127,7 @@ typedef struct {
 typedef struct {
     u32 type;
     u32 size;
-    u64 framebuffer_address;
+    u64 framebuffer_addr;
     u32 framebuffer_pitch;
     u32 framebuffer_width;
     u32 framebuffer_height;
@@ -236,91 +236,91 @@ typedef struct {
 typedef struct {
     u32 type;
     u32 size;
-    u32 load_base_address;
-} multiboot_tag_load_base_address;
+    u32 load_base_addr;
+} multiboot_tag_load_base_addr;
 
-void *multiboot_get_tag(uptr multiboot_info, u32 type);
+void *multiboot_get_tag(u32 type);
 
-static inline multiboot_tag_cmdline *multiboot_get_cmdline(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_CMDLINE);
+static inline multiboot_tag_cmdline *multiboot_get_cmdline() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_CMDLINE);
 }
 
-static inline multiboot_tag_bootloader_name *multiboot_get_bootloader_name(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_BOOT_LOADER_NAME);
+static inline multiboot_tag_bootloader_name *multiboot_get_bootloader_name() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_BOOT_LOADER_NAME);
 }
 
-static inline multiboot_tag_module *multiboot_get_module(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_MODULE);
+static inline multiboot_tag_module *multiboot_get_module() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_MODULE);
 }
 
-static inline multiboot_tag_basic_meminfo *multiboot_get_basic_meminfo(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_BASIC_MEMINFO);
+static inline multiboot_tag_basic_meminfo *multiboot_get_basic_meminfo() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_BASIC_MEMINFO);
 }
 
-static inline multiboot_tag_bootdev *multiboot_get_bootdev(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_BOOTDEV);
+static inline multiboot_tag_bootdev *multiboot_get_bootdev() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_BOOTDEV);
 }
 
-static inline multiboot_tag_mmap *multiboot_get_mmap(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_MMAP);
+static inline multiboot_tag_mmap *multiboot_get_mmap() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_MMAP);
 }
 
-static inline multiboot_tag_vbe *multiboot_get_vbe(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_VBE);
+static inline multiboot_tag_vbe *multiboot_get_vbe() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_VBE);
 }
 
-static inline multiboot_tag_framebuffer *multiboot_get_framebuffer(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_FRAMEBUFFER);
+static inline multiboot_tag_framebuffer *multiboot_get_framebuffer() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_FRAMEBUFFER);
 }
 
-static inline multiboot_tag_elf_sections *multiboot_get_elf_sections(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_ELF_SECTIONS);
+static inline multiboot_tag_elf_sections *multiboot_get_elf_sections() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_ELF_SECTIONS);
 }
 
-static inline multiboot_tag_apm *multiboot_get_apm(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_APM);
+static inline multiboot_tag_apm *multiboot_get_apm() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_APM);
 }
 
-static inline multiboot_tag_efi32 *multiboot_get_efi32(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_EFI32);
+static inline multiboot_tag_efi32 *multiboot_get_efi32() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_EFI32);
 }
 
-static inline multiboot_tag_efi64 *multiboot_get_efi64(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_EFI64);
+static inline multiboot_tag_efi64 *multiboot_get_efi64() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_EFI64);
 }
 
-static inline multiboot_tag_smbios *multiboot_get_smbios(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_SMBIOS);
+static inline multiboot_tag_smbios *multiboot_get_smbios() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_SMBIOS);
 }
 
-static inline multiboot_tag_acpi_old *multiboot_get_acpi_old(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_ACPI_OLD);
+static inline multiboot_tag_acpi_old *multiboot_get_acpi_old() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_ACPI_OLD);
 }
 
-static inline multiboot_tag_acpi_new *multiboot_get_acpi_new(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_ACPI_NEW);
+static inline multiboot_tag_acpi_new *multiboot_get_acpi_new() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_ACPI_NEW);
 }
 
-static inline multiboot_tag_network *multiboot_get_network(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_NETWORK);
+static inline multiboot_tag_network *multiboot_get_network() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_NETWORK);
 }
 
-static inline multiboot_tag_efi_mmap *multiboot_get_efi_mmap(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_EFI_MMAP);
+static inline multiboot_tag_efi_mmap *multiboot_get_efi_mmap() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_EFI_MMAP);
 }
 
-static inline bool multiboot_get_efi_bs(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_EFI_BS) != NULL;
+static inline bool multiboot_get_efi_bs() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_EFI_BS) != NULL;
 }
 
-static inline multiboot_tag_efi32_ih *multiboot_get_efi32_ih(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_EFI32_IH);
+static inline multiboot_tag_efi32_ih *multiboot_get_efi32_ih() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_EFI32_IH);
 }
 
-static inline multiboot_tag_efi64_ih *multiboot_get_efi64_ih(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_EFI64_IH);
+static inline multiboot_tag_efi64_ih *multiboot_get_efi64_ih() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_EFI64_IH);
 }
 
-static inline multiboot_tag_load_base_address *multiboot_get_load_base_address(uptr multiboot_info) {
-    return multiboot_get_tag(multiboot_info, MULTIBOOT_TAG_TYPE_LOAD_BASE_ADDRESS);
+static inline multiboot_tag_load_base_addr *multiboot_get_load_base_addr() {
+    return multiboot_get_tag(MULTIBOOT_TAG_TYPE_LOAD_BASE_ADDR);
 }

src/boot/start.asm

@@ -1,4 +1,5 @@
 global _start
+global multiboot_info
 extern kernel_start
 extern kernel_end
 extern x86_64_main