From 53fa3cd2bfdb122d773024612d8c1d71f0dd8188 Mon Sep 17 00:00:00 2001
From: Jon Santmyer <jon@jonsantmyer.com>
Date: Sat, 12 Sep 2026 22:00:09 -0400
Subject: add paging support

---
 arch/x86_64/hal/paging.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 73 insertions(+), 1 deletion(-)

(limited to 'arch/x86_64/hal/paging.c')

diff --git a/arch/x86_64/hal/paging.c b/arch/x86_64/hal/paging.c
index fb6dea7..507dfce 100644
--- a/arch/x86_64/hal/paging.c
+++ b/arch/x86_64/hal/paging.c
@@ -3,12 +3,12 @@
 #include "jove.h"
 #include "init.h"
 #include "config.h"
-#include "smp.h"
 #include "hal/obj.h"
 #include "lib/string.h"
 #include "lib/printf.h"
 #include "lib/panic.h"
 #include "idt.h"
+#include "api/syscall.h"
 
 PAGEALIGN page_t _kernel_pml4[512];
 PAGEALIGN page_t _kernel_pml3[512];
@@ -73,6 +73,78 @@ s_int_handle_pf_early(struct int_stackframe *frame)
     hcf();
 }
 
+int pagedir_map_frame(
+        jove_owned_obj_t *tgt, jove_owned_obj_t *untyped_obj, 
+        uintptr_t vptr, struct syscall_pagedir_flags flg)
+{
+    page_t *pml4 = obj_deref(tgt);
+    uintptr_t frame = obj_getvalue(untyped_obj);
+
+    size_t pml4i = PML4I(vptr);
+    if(!pml4[pml4i].p) return ENOMAP;
+
+    page_t *pml3 = (page_t*)(((uintptr_t)pml4[pml4i].paddr << 12) | IDENT_VIRT_BASE);
+    size_t pml3i = PML3I(vptr);
+    if(!pml3[pml3i].p) return ENOMAP;
+
+    page_t *pml2 = (page_t*)(((uintptr_t)pml3[pml3i].paddr << 12) | IDENT_VIRT_BASE);
+    size_t pml2i = PML2I(vptr);
+    if(!pml2[pml2i].p) return ENOMAP;
+
+    page_t *pml1 = (page_t*)(((uintptr_t)pml2[pml2i].paddr << 12) | IDENT_VIRT_BASE);
+    size_t pml1i = PML1I(vptr);
+    if(pml1[pml1i].p) return EEXIST;
+
+    pml1[pml1i].value = frame |
+        PAGE_PRESENT |
+        PAGE_USER |
+        (flg.writeable ? PAGE_WRITETHROUGH : 0) |
+        (flg.executable ? 0 : PAGE_XD);
+    return 0;
+}
+
+int pagedir_map_table(
+        jove_owned_obj_t *tgt, jove_owned_obj_t *untyped_obj, 
+        uintptr_t vptr, struct syscall_pagedir_flags flg)
+{
+    page_t *target_table = NULL;
+    page_t *pml4 = obj_deref(tgt);
+    uintptr_t frame = obj_getvalue(untyped_obj);
+
+    void *frame_ident = obj_deref(untyped_obj);
+    memset(frame_ident, 0, 0x1000);
+
+    size_t pml4i = PML4I(vptr);
+    if(!pml4[pml4i].p) {
+        target_table = &pml4[pml4i];
+        goto map_table;
+    }
+
+    page_t *pml3 = (page_t*)(((uintptr_t)pml4[pml4i].paddr << 12) | IDENT_VIRT_BASE);
+    size_t pml3i = PML3I(vptr);
+    if(!pml3[pml3i].p) {
+        target_table = &pml3[pml3i];
+        goto map_table;
+    }
+
+    page_t *pml2 = (page_t*)(((uintptr_t)pml3[pml3i].paddr << 12) | IDENT_VIRT_BASE);
+    size_t pml2i = PML2I(vptr);
+    if(!pml2[pml2i].p) {
+        target_table = &pml2[pml2i];
+        goto map_table;
+    }
+    return EHASMAP;
+
+map_table:
+    target_table->value = frame |
+        PAGE_PRESENT |
+        PAGE_USER |
+        (flg.writeable ? PAGE_WRITETHROUGH : 0) |
+        (flg.executable ? 0 : PAGE_XD);
+    return 0;
+}
+
+
 void
 paging_pml4_init(void)
 {
-- 
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