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authorDanny Holman <dholman@gymli.org>2024-06-25 13:00:47 -0500
committerDanny Holman <dholman@gymli.org>2024-06-25 13:00:47 -0500
commit2abe7e3e878b9b4ed3660b8f10eaf3caef2e0ea1 (patch)
treef5a19193962c4976c76b1bc87a37eeb8fcaca8f5
parent0dc4d97e70c17df56a260d31a1cb44881cf64520 (diff)
arch: i386: paging: reserve the last page table
Reserve the last, usable page table for temporary mappings, such as those required by the physical memory manager. Signed-off-by: Danny Holman <dholman@gymli.org>
-rw-r--r--arch/i386/kernel/paging.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/i386/kernel/paging.c b/arch/i386/kernel/paging.c
index b8e00af..a0bbb92 100644
--- a/arch/i386/kernel/paging.c
+++ b/arch/i386/kernel/paging.c
@@ -20,10 +20,13 @@ void paging_init(void) {
pt[GET_PTX(GET_VADDR(i))] = i | PD_PRES;
unmap_page(PAGE_TMP_MAP);
+ uintptr_t temp_pt = pfa_alloc(1);
+
uintptr_t phys_pd = pfa_alloc(1);
map_page(phys_pd, PAGE_TMP_MAP, PD_PRES | PD_RW);
uintptr_t *pd = (uintptr_t*)PAGE_TMP_MAP;
pd[GET_PDX(GET_VADDR(KSTART))] = phys_pt | PD_PRES | PD_RW;
+ pd[GET_PDX(PAGE_TMP_MAP)] = temp_pt | PD_PRES | PD_RW;
pd[1023] = phys_pd | PD_PRES | PD_RW;
unmap_page(PAGE_TMP_MAP);