From 211fa113f097bb3855ab9e025c574590c7a3a56f Mon Sep 17 00:00:00 2001
From: Stefan Lankes <slankes@eonerc.rwth-aachen.de>
Date: Mon, 29 Dec 2014 12:17:18 +0100
Subject: [PATCH] add helper function to map a page frame into the boot page
 table

---
 arch/x86/include/asm/page.h | 17 +++++++++++++----
 arch/x86/mm/page.c          | 16 +++++++++++++---
 2 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h
index 35ade15..8030bb9 100644
--- a/arch/x86/include/asm/page.h
+++ b/arch/x86/include/asm/page.h
@@ -112,9 +112,18 @@ size_t page_virt_to_phys(size_t vir);
  * Before calling page_init(), the bootstrap tables contain a simple identity
  * paging. Which is replaced by more specific mappings.
  */
-int page_init();
+int page_init(void);
 
-/** @brief Map a continious region of pages
+/** @brief Map one page into the boot page table
+ *
+ * @param viraddr
+ * @param phyaddr
+ * @param bits
+ * @return
+ */
+int page_map_bootmap(size_t viraddr, size_t phyaddr, size_t bits);
+
+/** @brief Map a continuous region of pages
  *
  * @param viraddr
  * @param phyaddr
@@ -124,7 +133,7 @@ int page_init();
  */
 int page_map(size_t viraddr, size_t phyaddr, size_t npages, size_t bits);
 
-/** @brief Unmap a continious region of pages
+/** @brief Unmap a continuous region of pages
  *
  * @param viraddr
  * @param npages
@@ -141,6 +150,6 @@ int page_unmap(size_t viraddr, size_t npages);
 int page_map_copy(task_t *dest);
 
 /** @brief Free a whole page map tree */
-int page_map_drop();
+int page_map_drop(void);
 
 #endif
diff --git a/arch/x86/mm/page.c b/arch/x86/mm/page.c
index 290c091..20c0afd 100644
--- a/arch/x86/mm/page.c
+++ b/arch/x86/mm/page.c
@@ -53,7 +53,7 @@ extern const void kernel_end;
 static spinlock_t kslock = SPINLOCK_INIT;
 
 /** This PGD table is initialized in entry.asm */
-extern size_t boot_map[PAGE_MAP_ENTRIES];
+extern size_t* boot_map;
 
 /** A self-reference enables direct access to all page tables */
 static size_t* self[PAGE_LEVELS] = {
@@ -77,6 +77,16 @@ size_t page_virt_to_phys(size_t addr)
 	return phy | off;
 }
 
+int page_map_bootmap(size_t viraddr, size_t phyaddr, size_t bits)
+{
+	if (BUILTIN_EXPECT(viraddr >= PAGE_MAP_ENTRIES*PAGE_SIZE, 0))
+		return -EINVAL;
+
+	boot_map[PAGE_MAP_ENTRIES + (viraddr >> PAGE_BITS)] = phyaddr | bits | PG_PRESENT;
+
+	return 0;
+}
+
 int page_map(size_t viraddr, size_t phyaddr, size_t npages, size_t bits)
 {
 	int lvl, ret = -ENOMEM;
@@ -160,7 +170,7 @@ int page_unmap(size_t viraddr, size_t npages)
 	return 0;
 }
 
-int page_map_drop()
+int page_map_drop(void)
 {
 	void traverse(int lvl, long vpn) {
 		long stop;
@@ -248,7 +258,7 @@ void page_fault_handler(struct state *s)
 	while(1) HALT;
 }
 
-int page_init()
+int page_init(void)
 {
 	size_t addr, npages;
 	int i;