Break GDT, TSS out of init.c, mmu.h.

[pintos-anon] / src / threads / loader.S

diff --git a/src/threads/loader.S b/src/threads/loader.S
index 5a0262b58733315296f85ae9ff429711c8d81854..535c442c4f1f39a0d59cf43aa51c0e3cc8beee33 100644 (file)
--- a/src/threads/loader.S
+++ b/src/threads/loader.S
@@ -1,5 +1,6 @@
-#include "mmu.h"
 #include "loader.h"
+#include "mmu.h"
+#include "gdt.h"
        
 ##############################################################################
 # Kernel loader.
@@ -12,6 +13,11 @@
 # first byte of the kernel, where start.S is linked.
 ##############################################################################
        
+/* Flags in control register 0 */
+#define CR0_PE 0x00000001      /* Protection Enable. */
+#define CR0_EM 0x00000004      /* (Floating-point) Emulation. */
+#define CR0_PG 0x80000000      /* Paging. */
+
 .globl start                           # Entry point   
 start: .code16                         # This runs in real mode
        cli                             # Disable interrupts
@@ -133,33 +139,33 @@ read_sector:
        cmpl $KERNEL_LOAD_PAGES*8 + 1, %ebx
        jnz read_sector
 
-##### Create temporary PDE and PTE, set page directory pointer, and turn
-##### on paging.
+##### Create temporary page directory and page table, set page
+##### directory pointer, and turn on paging.
 ##### FIXME? We could use a single 4 MB page instead of 1024 4 kB pages.
 
-       # Create PDE at 64 kB.
+       # Create page directory at 64 kB.
        movl $0x10000, %edi             
        movl %edi, %cr3
 
-       # Fill PDE with zeroes.
+       # Fill page directory with zeroes.
        subl %eax, %eax
        movl $0x400, %ecx
        rep stosl
 
-       # Set PDE entries for 0 and LOADER_PHYS_BASE to point to the
-       # PTE.
+       # Set PDEs for 0 and LOADER_PHYS_BASE to point to the
+       # page table.
        movl $0x11000 | PG_U | PG_W | PG_P, %eax
        movl %eax, 0x10000
        movl %eax, 0x10000 | (LOADER_PHYS_BASE >> 20)
 
-       # Initialize PTE.
+       # Initialize page table.
        movl $PG_U | PG_W | PG_P, %eax
        movl $0x400, %ecx
 1:     stosl
        addl $0x1000, %eax
        loop 1b
 
-       # Enable paging.
+       # Turn on paging.
        movl %cr0, %eax
        orl $CR0_PG, %eax
        movl %eax, %cr0
@@ -206,17 +212,17 @@ panicmsg:
        .byte 0
 
 ##### Memory size in 4 kB pages.
-       .org LOADER_RAM_PAGES
+       .org LOADER_RAM_PAGES - LOADER_BASE
 ram_pages:
        .long 0
 
 ##### Command-line arguments inserted by another utility.
 ##### The loader doesn't use these, but we note their
 ##### location here for easy reference.
-       .org LOADER_CMD_LINE
+       .org LOADER_CMD_LINE - LOADER_BASE
 cmd_line:
        .fill 0x80, 1, 0
 
 ##### Boot-sector signature for BIOS inspection.
-       .org LOADER_BIOS_SIG
+       .org LOADER_BIOS_SIG - LOADER_BASE
        .word 0xaa55