Reinitialize paging.

6 files changed, 75 insertions, 10 deletions

diff --git a/kernel/SConscript b/kernel/SConscript
index 47af722..3688850 100644
--- a/kernel/SConscript
+++ b/kernel/SConscript
@@ -34,6 +34,7 @@ kernel = env.Kernel('kernel', [
 	'idt.c',
 	'irq.c',
 	'main.c',
+	'paging.c',
 	'palloc.c',
 	'panic.c',
 	'printf.c',
diff --git a/kernel/entry.c b/kernel/entry.c
index 6058910..2ec5089 100644
--- a/kernel/entry.c
+++ b/kernel/entry.c
@@ -1,4 +1,5 @@
 #include "kernel.h"
+#include "paging.h"
 
 extern void main();
 
@@ -46,25 +47,27 @@ void entry_main(uint32_t mb_magic, multiboot_info_t* mb_info) {
 		entry_pagedir[i] = 0;
 		
 		// Identity mapping of the current code.
-		//entry_pagetable_low[i] = ((uint32_t)&addr_phys & 0xffc00000) | (i << 12) | 0x003;
-		entry_pagetable_low[i] = ((uint32_t)&addr_phys & 0xffc00000) | (i << 12) | 0x007;
+		entry_pagetable_low[i] = ((uint32_t)&addr_phys & 0xffc00000) | (i << 12) | P1_P | P1_W;
 		
 		// Map kernelspace.
 		if((i << 12) < ((uint32_t)&addr_virt_end & 0x003fffff)) {
-			entry_pagetable_high[i] = ((uint32_t)&addr_load_virt + (i << 12)) | 0x003;
+			entry_pagetable_high[i] = ((uint32_t)&addr_load_virt + (i << 12)) | P1_P | P1_W | P1_G;
 		} else {
 			entry_pagetable_high[i] = 0;
 		}
 	}
 	
-	entry_pagetable_high[((uint32_t)&multiboot_info & 0x003ff000) >> 12] = (uint32_t)&entry_multiboot | 0x003;
+	entry_pagetable_high[((uint32_t)&multiboot_info & 0x003ff000) >> 12] = (uint32_t)&entry_multiboot | P1_P | P1_W | P1_G;
 	
-	entry_pagedir[(uint32_t)&addr_phys >> 22] = (uint32_t)&entry_pagetable_low | 0x007;
-	entry_pagedir[(uint32_t)&addr_virt >> 22] = (uint32_t)&entry_pagetable_high | 0x003;
+	entry_pagedir[(uint32_t)&addr_phys >> 22] = (uint32_t)&entry_pagetable_low | P2_P | P2_W;
+	entry_pagedir[(uint32_t)&addr_virt >> 22] = (uint32_t)&entry_pagetable_high | P2_P | P2_W | P2_G;
+	
+	// Map map_p1.
+	entry_pagedir[1022] = (uint32_t)&entry_pagedir | P2_P | P2_W | P2_G;
 	
 	// Mapping stack to top without creating another page directory.
-	entry_pagetable_high[1023] = (uint32_t)&entry_stack | 0x003;
-	entry_pagedir[1023] = (uint32_t)&entry_pagetable_high | 0x003;
+	entry_pagetable_low[1023] = (uint32_t)&entry_stack | P1_P | P1_W | P1_G;
+	entry_pagedir[1023] = (uint32_t)&entry_pagetable_low | P2_P | P2_W | P2_G;
 	
 	// Enable paging.
 	asm volatile(
diff --git a/kernel/idt.c b/kernel/idt.c
index 66e1fb8..55c1bae 100644
--- a/kernel/idt.c
+++ b/kernel/idt.c
@@ -76,7 +76,7 @@ isr_panic(31);
 #include "irq.h"
 
 void tick() {
-	*(uint16_t*)(0xb8890) += 1;
+	//*(uint16_t*)(0xb8890) += 1;
 	irq_reset();
 }
 
diff --git a/kernel/main.c b/kernel/main.c
index db22f07..d6de534 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -1,6 +1,7 @@
 #include "kernel.h"
 #include "printf.h"
 #include "palloc.h"
+#include "paging.h"
 #include "gdt.h"
 #include "idt.h"
 #include "irq.h"
@@ -11,6 +12,9 @@ void main() {
 	palloc_init();
 	printf("Page allocator initiated.\n");
 	
+	paging_reinit();
+	printf("Paging reinitialized.\n");
+	
 	gdt_init();
 	printf("GDT set.\n");
 	
@@ -27,6 +31,7 @@ void main() {
 	
 	asm volatile("sti");
 	
+	/*
 	asm volatile(
 		"push $0x23\n"
 		"push $entry_stack_top\n"
@@ -35,7 +40,7 @@ void main() {
 		"push %0\n"
 		"iret\n"
 		:: "r" (multiboot_info.mods_addr[0].mod_start)
-	);
+	); */
 	
 	printf("Halting.\n");
 	
diff --git a/kernel/paging.c b/kernel/paging.c
new file mode 100644
index 0000000..22da7e8
--- /dev/null
+++ b/kernel/paging.c
@@ -0,0 +1,26 @@
+#include "paging.h"
+#include "kernel.h"
+
+#define invlpg(page) asm volatile("invlpg (%0)" :: "r" (page))
+
+void paging_reinit() {
+	map_p1.l[(uint32_t)&map_p2 >> 12] = (uint32_t)&entry_pagedir | P1_P | P1_W | P1_G;
+	
+	invlpg(&map_p2);
+	
+	for(unsigned int i = 0; i < 1024; i++) {
+		if(map_p2[i] & P2_P && !(map_p2[i] & P2_G)) {
+			map_p2[i] = 0;
+		}
+		
+		if(map_p1.b[0x300][i] & P1_P && !(map_p1.b[0x300][i] & P1_G)) {
+			map_p1.b[0x300][i] = 0;
+		}
+		
+		if(map_p1.b[0x3ff][i] & P1_P && !(map_p1.b[0x3ff][i] & P1_G)) {
+			map_p1.b[0x3ff][i] = 0;
+		}
+	}
+	
+	// TODO: Set CR4.PGE.
+}
diff --git a/kernel/paging.h b/kernel/paging.h
new file mode 100644
index 0000000..24409d9
--- /dev/null
+++ b/kernel/paging.h
@@ -0,0 +1,30 @@
+#ifndef PAGING_H
+#define PAGING_H
+
+enum {
+	P1_P   = 0x001,
+	P1_W   = 0x002,
+	P1_U   = 0x004,
+	P1_PWT = 0x008,
+	P1_PCD = 0x010,
+	P1_A   = 0x020,
+	P1_D   = 0x040,
+	P1_PAT = 0x080,
+	P1_G   = 0x100,
+};
+
+enum {
+	P2_P   = 0x001,
+	P2_W   = 0x002,
+	P2_U   = 0x004,
+	P2_PWT = 0x008,
+	P2_PCD = 0x010,
+	P2_A   = 0x020,
+	P2_D   = 0x040,
+	P2_PS  = 0x080,
+	P2_G   = 0x100,
+};
+
+void paging_reinit();
+
+#endif