ipu init

bootmain.c

@@ -10,75 +10,75 @@
 #include "x86.h"
 #include "memlayout.h"
 
-#define SECTSIZE  512
+#define SECTSIZE 512
 
-void readseg(uchar*, uint, uint);
+void readseg(uchar *, uint, uint);
 
-void
-bootmain(void)
+void bootmain(void)
 {
   struct elfhdr *elf;
   struct proghdr *ph, *eph;
   void (*entry)(void);
-  uchar* pa;
+  uchar *pa;
 
-  elf = (struct elfhdr*)0x10000;  // scratch space
+  elf = (struct elfhdr *)0x10000; // scratch space
 
   // Read 1st page off disk
-  readseg((uchar*)elf, 4096, 0);
+  readseg((uchar *)elf, 4096, 0);
 
   // Is this an ELF executable?
-  if(elf->magic != ELF_MAGIC)
-    return;  // let bootasm.S handle error
+  if (elf->magic != ELF_MAGIC)
+    return; // let bootasm.S handle error
 
   // Load each program segment (ignores ph flags).
-  ph = (struct proghdr*)((uchar*)elf + elf->phoff);
+  ph = (struct proghdr *)((uchar *)elf + elf->phoff);
   eph = ph + elf->phnum;
-  for(; ph < eph; ph++){
-    pa = (uchar*)ph->paddr;
+  for (; ph < eph; ph++)
+  {
+    pa = (uchar *)ph->paddr;
     readseg(pa, ph->filesz, ph->off);
-    if(ph->memsz > ph->filesz)
+    if (ph->memsz > ph->filesz)
       stosb(pa + ph->filesz, 0, ph->memsz - ph->filesz);
   }
 
   // Call the entry point from the ELF header.
   // Does not return!
-  entry = (void(*)(void))(elf->entry);
+  entry = (void (*)(void))(elf->entry);
   entry();
 }
 
-void
-waitdisk(void)
+void waitdisk(void)
 {
   // Wait for disk ready.
-  while((inb(0x1F7) & 0xC0) != 0x40)
+  while ((inb(0x1F7) & 0xC0) != 0x40)
     ;
 }
 
 // Read a single sector at offset into dst.
-void
-readsect(void *dst, uint offset)
+void readsect(void *dst, uint offset)
 {
   // Issue command.
   waitdisk();
-  outb(0x1F2, 1);   // count = 1
+  outb(0x1F2, 1); // count = 1
   outb(0x1F3, offset);
   outb(0x1F4, offset >> 8);
   outb(0x1F5, offset >> 16);
   outb(0x1F6, (offset >> 24) | 0xE0);
-  outb(0x1F7, 0x20);  // cmd 0x20 - read sectors
+  outb(0x1F7, 0x20); // cmd 0x20 - read sectors
 
   // Read data.
   waitdisk();
-  insl(0x1F0, dst, SECTSIZE/4);
+  insl(0x1F0, dst, SECTSIZE / 4);
 }
 
 // Read 'count' bytes at 'offset' from kernel into physical address 'pa'.
 // Might copy more than asked.
-void
-readseg(uchar* pa, uint count, uint offset)
+// pa: physical address
+// count: number of bytes to read
+// offset: disk offset by bytes
+void readseg(uchar *pa, uint count, uint offset)
 {
-  uchar* epa;
+  uchar *epa;
 
   epa = pa + count;
 
@@ -91,6 +91,13 @@ readseg(uchar* pa, uint count, uint offset)
   // If this is too slow, we could read lots of sectors at a time.
   // We'd write more to memory than asked, but it doesn't matter --
   // we load in increasing order.
-  for(; pa < epa; pa += SECTSIZE, offset++)
+  for (; pa < epa; pa += SECTSIZE, offset++)
     readsect(pa, offset);
 }
+
+// readseg(100, 512, 10);
+// pa == 90
+// offset: block単位に変わる
+// 0sector目はbootloader
+// 1sector目からkernel
+// offsetはdiskの何セクター目を読むか

entry.S

@@ -1,7 +1,7 @@
 # The xv6 kernel starts executing in this file. This file is linked with
 # the kernel C code, so it can refer to kernel symbols such as main().
 # The boot block (bootasm.S and bootmain.c) jumps to entry below.
-        
+
 # Multiboot header, for multiboot boot loaders like GNU Grub.
 # http://www.gnu.org/software/grub/manual/multiboot/multiboot.html
 #

sample.c

@@ -0,0 +1,5 @@
+#include <stdio.h>
+int main() {
+  static long int aaaa[0x1000000];
+  return 0;
+}

sample1.S

@@ -0,0 +1,2 @@
+dummy_label:
+    nop