1 files changed, 46 insertions, 58 deletions

diff --git a/kernel.cc b/kernel.cc
index b2e2b01..3045374 100644
--- a/kernel.cc
+++ b/kernel.cc
@@ -8,10 +8,10 @@
 #error "This tutorial needs to be compiled with a ix86-elf compiler"
 #endif
 
-#include "multiboot2.h"
-#include "vga.h"
 #include <stdlib.h>
 #include <types.h>
+#include "multiboot2.h"
+#include "vga.h"
 
 extern "C" void kernel_main(uint32_t mb_magic, uint32_t mb_addr) {
   VGA terminal;
@@ -19,69 +19,57 @@ extern "C" void kernel_main(uint32_t mb_magic, uint32_t mb_addr) {
 
   printk("Hello, kernel World!\n");
 
-  printk("multiboot magic: 0x", mb_magic,
-         mb_magic == MULTIBOOT2_BOOTLOADER_MAGIC ? " is valid" : " is invalid",
-         '\n');
-  printk("multiboot addr: 0x", mb_addr, '\n');
+  printk("multiboot magic: ", uhex{mb_magic}, mb_magic == MULTIBOOT2_BOOTLOADER_MAGIC ? " valid" : " invalid", '\n');
+  printk("multiboot  addr: ", uhex{mb_addr}, !(mb_addr & 7) ? " is aligned" : " is not aligned", '\n');
 
-  if (mb_addr & 7) {
-    printk("unaligned mbi\n");
-  }
+  struct multiboot_tag* tag;
+  const uint32_t size = *(unsigned*)mb_addr;
+  printk("Announced mbi size ", size, '\n');
 
-  struct multiboot_tag *tag;
-  const uint32_t size = *(unsigned *)mb_addr;
-  printk("Announced mbi size 0x", size, '\n');
+  for (tag = (struct multiboot_tag*)(mb_addr + 8); tag->type != MULTIBOOT_TAG_TYPE_END;
+       tag = (struct multiboot_tag*)((multiboot_uint8_t*)tag + ((tag->size + 7) & ~7))) {
+    switch (tag->type) {
+      case MULTIBOOT_TAG_TYPE_CMDLINE: {
+        auto* t = reinterpret_cast<multiboot_tag_string*>(tag);
+        printk("Command line = [", t->string, "]\n");
+      } break;
 
-  for (tag = (struct multiboot_tag *)(mb_addr + 8);
-       tag->type != MULTIBOOT_TAG_TYPE_END;
-       tag = (struct multiboot_tag *)((multiboot_uint8_t *)tag +
-                                      ((tag->size + 7) & ~7))) {
+      case MULTIBOOT_TAG_TYPE_BOOT_LOADER_NAME: {
+        auto* t = reinterpret_cast<multiboot_tag_string*>(tag);
+        printk("Boot loader name = [", t->string, "]\n");
+      } break;
 
-    switch (tag->type) {
-    case MULTIBOOT_TAG_TYPE_CMDLINE:
-      printk("Command line = [", ((struct multiboot_tag_string *)tag)->string,
-             "]\n");
-      break;
-    case MULTIBOOT_TAG_TYPE_BOOT_LOADER_NAME:
-      printk("Boot loader name = [",
-             ((struct multiboot_tag_string *)tag)->string, "]\n");
-      break;
-    case MULTIBOOT_TAG_TYPE_BASIC_MEMINFO:
-      printk("mem_lower = ",
-             ((struct multiboot_tag_basic_meminfo *)tag)->mem_lower, "KB\n",
-             "mem_upper = ",
-             ((struct multiboot_tag_basic_meminfo *)tag)->mem_upper, "KB\n");
-      break;
-    case MULTIBOOT_TAG_TYPE_BOOTDEV:
-      printk("Boot device 0x", ((struct multiboot_tag_bootdev *)tag)->biosdev,
-             " slice ", ((struct multiboot_tag_bootdev *)tag)->slice, " part ",
-             ((struct multiboot_tag_bootdev *)tag)->part, '\n');
-      break;
-    case MULTIBOOT_TAG_TYPE_MMAP: {
-      multiboot_memory_map_t *mmap;
+      case MULTIBOOT_TAG_TYPE_BOOTDEV: {
+        auto* t = reinterpret_cast<multiboot_tag_bootdev*>(tag);
+        printk("Boot device ", uhex{t->biosdev}, " slice ", t->slice, " part ", t->part, '\n');
+      } break;
+
+      case MULTIBOOT_TAG_TYPE_BASIC_MEMINFO: {
+        auto* t = reinterpret_cast<multiboot_tag_basic_meminfo*>(tag);
+        printk("mem_lower = ", t->mem_lower, "KB\n", "mem_upper = ", t->mem_upper, "KB\n");
+      } break;
+
+      case MULTIBOOT_TAG_TYPE_MMAP: {
+        auto* t = reinterpret_cast<multiboot_tag_mmap*>(tag);
+        multiboot_memory_map_t* mmap;
 
-      printk("mmap\n");
+        printk("memory map\n");
+        for (mmap = t->entries; (multiboot_uint8_t*)mmap < (multiboot_uint8_t*)tag + tag->size;
+             mmap = (multiboot_memory_map_t*)((unsigned long)mmap + ((struct multiboot_tag_mmap*)tag)->entry_size)) {
+          printk("  base_addr = ", uhex{(unsigned)(mmap->addr >> 32)}, ' ', uhex{(unsigned)(mmap->addr & 0xffffffff)});
+          printk(" length = ", (unsigned)(mmap->len >> 32), ' ', (unsigned)(mmap->len & 0xffffffff));
+          printk(" type = ", (unsigned)mmap->type, '\n');
+        }
+      } break;
 
-      for (mmap = ((struct multiboot_tag_mmap *)tag)->entries;
-           (multiboot_uint8_t *)mmap < (multiboot_uint8_t *)tag + tag->size;
-           mmap = (multiboot_memory_map_t *)((unsigned long)mmap +
-                                             ((struct multiboot_tag_mmap *)tag)
-                                                 ->entry_size))
-        printk(" base_addr = 0x", (unsigned)(mmap->addr >> 32), ' ',
-               (unsigned)(mmap->addr & 0xffffffff), " length = 0x",
-               (unsigned)(mmap->len >> 32), ' ',
-               (unsigned)(mmap->len & 0xffffffff), " type = 0x",
-               (unsigned)mmap->type, '\n');
-    } break;
-    default:
-      printk("Tag 0x", tag->type, ", Size 0x", tag->size, '\n');
-      break;
-    } // switch(tag->type)
-  }   // for(each tag)
+      default:
+        printk("Tag ", tag->type, ", Size ", tag->size, '\n');
+        break;
+    }  // switch(tag->type)
+  }    // for(each tag)
 
-  tag = (struct multiboot_tag *)((multiboot_uint8_t *)tag +
-                                 ((tag->size + 7) & ~7));
-  printk("Total mbi size 0x", (unsigned)tag - mb_addr, '\n');
+  tag = (struct multiboot_tag*)((multiboot_uint8_t*)tag + ((tag->size + 7) & ~7));
+  printk("Total mbi size ", (unsigned)tag - mb_addr, '\n');
 
   abort();
 }