add paging

.gitignore

@@ -2,6 +2,6 @@
 *.swp
 *.o
 *.d
+cscope.*
 boot.bin
 hd.img
-orange/

boot/Makefile

@@ -19,8 +19,8 @@ all: $(BINFILE) $(HDIMAGE)
 $(HDIMAGE):
  dd if=/dev/zero of=$@ bs=1M count=32
 
-$(BINFILE): $(OBJFILES)
- ld $(LDFLAGS) -o $@ $+
+$(BINFILE): $(OBJFILES) $(LDSCRIPT)
+ ld $(LDFLAGS) -o $@ $(OBJFILES)
 
 clean:
  -@rm -fr $(OBJFILES) $(DEPFILES) $(BINFILE)

boot/boot.ld

@@ -5,6 +5,7 @@ MEMORY
 {
  BOOT : ORIGIN = 0x7c00, LENGTH = 512
  MAIN : ORIGIN = 0X10000, LENGTH = 16M
+ PAGE : ORIGIN = 0X100000, LENGTH = 8M
 }
 SECTIONS
 {
@@ -23,4 +24,10 @@ SECTIONS
  *(.text)
  *(.*)
  } > MAIN = 0
+
+ .page :
+ {
+ _cmain_end = .;
+ } > PAGE = 0
+
 }

boot/gdt.c

@@ -25,7 +25,7 @@ gdt_init()
  } __attribute__ ((packed)) gdtr;
  gdtr.addr = (unsigned long)gdt;
  gdtr.limit = GDT_MAX_DESCS * sizeof(u64);
- __asm__("lgdt %0"::"m"(gdtr));
+ __asm__ __volatile__("lgdt %0"::"m"(gdtr));
 }
 
 inline void

boot/interrupt.c

@@ -56,7 +56,7 @@ init_idt()
  } __attribute__ ((packed)) idtr;
  idtr.addr = (u32)idt;
  idtr.limit = IDT_MAX_DESCS * sizeof(u64);
- __asm__(
+ __asm__ __volatile__(
  "cli\n\t"
  "lidt %0\n\t"
  ::"m"(idtr)

boot/main.c

@@ -21,8 +21,8 @@ cmain()
  gdt_init();
  reload_segs(SEL_DATA_PL0);
  tw_printf("%%%s: (%d=0x%x=0b%b)\n", "cmain", 10, 10, 10);
- show_mem_map();
  interrupt_init();
+ mem_init();
  keyboard_init();
  timer_init();
 

boot/mem.c

@@ -1,3 +1,4 @@
+#include "common.h"
 #include "mem.h"
 #include "video.h"
 
@@ -45,7 +46,7 @@ tw_memcmp(char *dst, char *src, int len)
  return ret;
 }
 
-void
+static void
 show_mem_map()
 {
  long cnt = *(long *)MEM_DESC_CNT_ADDR, i;
@@ -59,3 +60,67 @@ show_mem_map()
  descs[i].type);
  }
 }
+
+static void
+add_a_page(u32 addr, u32 *page_dir)
+{
+ int dir_index, tbl_index;
+ u32 *page_tbl;
+
+ dir_index = (addr>>22)&0x3ff;
+ tbl_index = (addr>>12)&0x3ff;
+ page_dir[dir_index] |= 1;
+ page_tbl = (u32 *)((page_dir[dir_index])&0xfffff000);
+ page_tbl[tbl_index] |= 1;
+}
+
+extern char* _cmain_end;
+static void
+setup_page()
+{
+ int i;
+ u32 *page_dir = (u32 *)(((u32)(&_cmain_end) & 0xfffff000) + 0x1000);
+ u32 *page_tbl = page_dir + 0x1000;
+ u32 addr = 0;
+ long cnt = *(long *)MEM_DESC_CNT_ADDR;
+ mem_desc_s *descs = (mem_desc_s *)MEM_MAP_ADDR;
+
+ tw_printf("0x%x, 0x%x\n", page_dir, page_tbl);
+ // setup blank page directory
+ for (i = 0; i < 1024; i++) {
+ page_dir[i] = (u32)(&page_tbl[i*1024]) | 2;
+ }
+ for (i = 0; i < 1024*1024; i++) {
+ page_tbl[i] = addr | 2;
+ addr += 0x1000;
+ }
+ for (i = 0; i < cnt; i++) {
+ for (addr = 0; addr < descs[i].length_low; addr += 0x1000) {
+ add_a_page(descs[i].base_low + addr, page_dir);
+ }
+ }
+ // add video memory map
+ for (i = 0; i < VIDEO_RAM_SIZE; i += 0x1000) {
+ add_a_page(VIDEO_RAM_START_ADDR + i, page_dir);
+ }
+ // add local apic memory map
+ for (i = 0; i < 0x1000; i += 0x1000) {
+ add_a_page(0xfee00000+i, page_dir);
+ }
+
+ // tell cpu the page directory address
+ __asm__ __volatile__("movl %0, %%cr3"::"b"(page_dir));
+ // enable paging
+ __asm__ __volatile__(
+ "movl %cr0, %eax\n\t"
+ "orl $0x80000000, %eax\n\t"
+ "movl %eax, %cr0\n\t"
+ );
+}
+
+void
+mem_init()
+{
+ show_mem_map();
+ setup_page();
+}

boot/mem.h

@@ -31,6 +31,6 @@ typedef struct {
  long type;
 } mem_desc_s;
 
-void show_mem_map(void);
+void mem_init(void);
 int tw_memcmp(char *dst, char *src, int len);
 #endif /* end of include guard: MEM_H */