3 files changed, 15 insertions, 11 deletions
diff --git a/kernel/include/paging.h b/kernel/include/paging.h
index 7082e2e..2e1f844 100644
--- a/kernel/include/paging.h
+++ b/kernel/include/paging.h
@@ -13,13 +13,11 @@ pagedir_t *get_kernel_pagedir();
 
 void switch_pagedir(pagedir_t *pd);
 
-// The three functions below DO NOT DEPEND on argument pd for
-// addresses above K_HIGHHALF_ADDR, so just pass 0 to map/unmap in kernel space.
-uint32_t pd_get_frame(pagedir_t *pd, size_t vaddr);		// get physical frame for virtual address
-int pd_map_page(pagedir_t *pd,
-				size_t vaddr, uint32_t frame_id,
+// these functions are always relative to the currently mapped page directory
+uint32_t pd_get_frame(size_t vaddr);		// get physical frame for virtual address
+int pd_map_page(size_t vaddr, uint32_t frame_id,
 				uint32_t rw);		// returns nonzero on error
-void pd_unmap_page(pagedir_t *pd, size_t vaddr);	// does nothing if page wasn't mapped
+void pd_unmap_page(size_t vaddr);	// does nothing if page not mapped
 
 pagedir_t *create_pagedir();		// returns zero on error
 void delete_pagedir(pagedir_t *pd);
diff --git a/kernel/include/region.h b/kernel/include/region.h
index 3c64081..1628370 100644
--- a/kernel/include/region.h
+++ b/kernel/include/region.h
@@ -29,9 +29,4 @@ size_t region_alloc(size_t size, uint32_t type, page_fault_handler_t pf);	// ret
 region_info_t *find_region(size_t addr);
 void region_free(size_t addr);
 
-#define N_PAGES_IN_PT_REGION 4
-// special call for use by paging code
-// allocates a region of N_PAGES_IN_PT_REGION pages
-size_t region_alloc_for_pt();	
-
 void dbg_print_region_stats();
diff --git a/kernel/include/sys.h b/kernel/include/sys.h
index a9d2d4c..ff98c60 100644
--- a/kernel/include/sys.h
+++ b/kernel/include/sys.h
@@ -22,6 +22,10 @@ static inline uint16_t inw(uint16_t port) {
 	return ret;
 }
 
+static inline void invlpg(size_t addr) {
+	asm volatile("invlpg (%0)" : : "r"(addr) : "memory");
+}
+
 void panic(const char* message, const char* file, int line);
 void panic_assert(const char* assertion, const char* file, int line);
 #define PANIC(s) panic(s, __FILE__, __LINE__);
@@ -37,6 +41,13 @@ void panic_assert(const char* assertion, const char* file, int line);
 #define PAGE_ALIGN_DOWN(x)	(((size_t)x) & PAGE_MASK) 
 #define PAGE_ALIGN_UP(x)  	((((size_t)x)&(~PAGE_MASK)) == 0 ? ((size_t)x) : (((size_t)x) & PAGE_MASK) + PAGE_SIZE)
 #define PAGE_ID(x)			(((size_t)x) / PAGE_SIZE)
+#define PAGE_SHIFT		12
+#define PT_SHIFT		10
+// PAGE_SHIFT + PT_SHIFT + PT_SHIFT = 32
+#define N_PAGES_IN_PT		1024
+#define PD_MIRROR_ADDR	0xFFC00000		// last 4MB used for PD mirroring
+#define LAST_KERNEL_ADDR	PD_MIRROR_ADDR
+#define FIRST_KERNEL_PT	(K_HIGHHALF_ADDR >> (PAGE_SHIFT+PT_SHIFT))	// must be 768
 
 #define MASK4			0xFFFFFFFC
 #define ALIGN4_UP(x)	((((size_t)x)&(~MASK4)) == 0 ? ((size_t)x) : (((size_t)x) & MASK4) + 4)