# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1301196506 -10800
# Node ID 096807345aa28ecda3fe03e36f33a4a034fbcd51
# Parent  098b1cb5eeaa748fb49f16adcb78c324701c301e
fixed the stupid mistake. forgot to page-align the page directory

diff -r 098b1cb5eeaa -r 096807345aa2 src/vm.c
--- a/src/vm.c	Sat Mar 26 21:39:14 2011 +0200
+++ b/src/vm.c	Sun Mar 27 06:28:26 2011 +0300
@@ -16,7 +16,7 @@
 static void pgfault(int inum, uint32_t err);
 
 /* page directory */
-static uint32_t pgdir[1024];
+static uint32_t *pgdir;
 
 #define KMEM_START		0xc0000000
 #define IDMAP_START		0xa0000
@@ -31,6 +31,7 @@
 {
 	init_mem(mb);
 
+	pgdir = (uint32_t*)alloc_phys_page();
 	memset(pgdir, 0, sizeof pgdir);
 
 	/* map the video memory and kernel code 1-1 */
@@ -51,6 +52,8 @@
 	if(!(pgdir[diridx] & PG_PRESENT)) {
 		uint32_t addr = alloc_phys_page();
 		pgtbl = (uint32_t*)addr;
+		memset(pgtbl, 0, PGSIZE);
+
 		pgdir[diridx] = addr | (attr & ATTR_PGDIR_MASK) | PG_PRESENT;
 	} else {
 		pgtbl = (uint32_t*)(pgdir[diridx] & ADDR_PGENT_MASK);
@@ -128,6 +131,25 @@
 	}
 */
 
+uint32_t virt_to_phys(uint32_t vaddr)
+{
+	uint32_t pgaddr, *pgtbl;
+	int diridx = ADDR_TO_PGTBL(vaddr);
+	int pgidx = ADDR_TO_PGTBL_PG(vaddr);
+
+	if(!(pgdir[diridx] & PG_PRESENT)) {
+		panic("virt_to_phys(%x): page table %d not present\n", vaddr, diridx);
+	}
+	pgtbl = (uint32_t*)(pgdir[diridx] & PGENT_ADDR_MASK);
+
+	if(!(pgtbl[pgidx] & PG_PRESENT)) {
+		panic("virt_to_phys(%x): page %d not present\n", vaddr, ADDR_TO_PAGE(vaddr));
+	}
+	pgaddr = pgtbl[pgidx] & PGENT_ADDR_MASK;
+
+	return pgaddr | ADDR_TO_PGOFFS(vaddr);
+}
+
 static void pgfault(int inum, uint32_t err)
 {
 	printf("~~~~ PAGE FAULT ~~~~\n");
diff -r 098b1cb5eeaa -r 096807345aa2 src/vm.h
--- a/src/vm.h	Sat Mar 26 21:39:14 2011 +0200
+++ b/src/vm.h	Sun Mar 27 06:28:26 2011 +0300
@@ -20,6 +20,7 @@
 #define PGSIZE					4096
 #define PGOFFS_MASK				0xfff
 #define PGNUM_MASK				0xfffff000
+#define PGENT_ADDR_MASK			PGNUM_MASK
 
 #define ADDR_TO_PAGE(x)		((uint32_t)(x) >> 12)
 #define PAGE_TO_ADDR(x)		((uint32_t)(x) << 12)
@@ -39,4 +40,6 @@
 
 void map_mem_range(uint32_t vaddr, size_t sz, uint32_t paddr, unsigned int attr);
 
+uint32_t virt_to_phys(uint32_t vaddr);
+
 #endif	/* VM_H_ */