added mm_early_vpage_alloc(); kernel still crashing...

git-svn-id: svn://anubis/hos/trunk@98 5b3e749e-e535-0410-8002-a9bb6afbdfca

kernel/mm/mm.cc

@@ -131,6 +131,8 @@ void mm_bootstrap()
     /* move the heap back to after the page allocation pages */
     mm_heap_base = (u32_t) &page_alloc_pages[last_page_alloc_page + 1];
 
+    /* ok, now mm_early_vpage_alloc() should be functional */
+
     /* allocate the page directory */
     u32_t page_directory_phys = mm_early_page_alloc();
     early_page_directory_ptr = (pagedirectory_t *)
@@ -359,6 +361,19 @@ u32_t mm_page_alloc()
     return page_address;
 }
 
+/**************************************************************************
+ * This function allocates a virtual page. It should only be called       *
+ * during the bootstrap process, before the kernel begins its normal      *
+ * operation. It adjusts the heap pointer to push it back beyond any      *
+ * bootstrap pages allocated.                                             *
+ *************************************************************************/
+u32_t mm_early_vpage_alloc()
+{
+    u32_t vaddress = mm_heap_base;
+    mm_heap_base += PAGE_SIZE;
+    return vaddress;
+}
+
 void mm_print_memory_map()
 {
     kprintf("Bootloader provided memory map:\n");

kernel/mm/mm.h

@@ -56,6 +56,7 @@ int mm_map(u32_t virtual_address, u32_t physical_address,
 
 u32_t mm_early_page_alloc();
 u32_t mm_page_alloc();
+u32_t mm_early_vpage_alloc();
 
 void mm_print_memory_map();