arch: i386: paging: make a temp map in init_page_table

Make a temporary mapping for a alloc'd page in init_page_table. This
ensures that the mapping is firmly inside the page table set aside for
page accounting structures.

Signed-off-by: Danny Holman <dholman@gymli.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/arch/i386/kernel/paging.c b/arch/i386/kernel/paging.c
index ddab223..96ad2ce 100644
--- a/arch/i386/kernel/paging.c
+++ b/arch/i386/kernel/paging.c
@@ -24,9 +24,10 @@ uintptr_t* init_page_table(void) {
         if ((uintptr_t)ret == PFA_ALLOC_ERR)
                 return NULL;
 
-        map_page(NULL, (uintptr_t)ret, (uintptr_t)ret+0x20000000, PD_PRES | PD_RW);
-        memset((char*)ret, 0, PAGE_SIZE);
-        unmap_page(NULL, (uintptr_t)ret);
+        uintptr_t *temp_map = (uintptr_t*)0xD0001000;
+        map_page(NULL, (uintptr_t)ret, (uintptr_t)temp_map, PD_PRES | PD_RW);
+        memset((char*)temp_map, 0, PAGE_SIZE);
+        unmap_page(NULL, (uintptr_t)temp_map);
         return ret;
 }