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

---
 sys/syscall_pagedir.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 112 insertions(+)
 create mode 100644 sys/syscall_pagedir.c

(limited to 'sys/syscall_pagedir.c')

diff --git a/sys/syscall_pagedir.c b/sys/syscall_pagedir.c
new file mode 100644
index 0000000..144a02b
--- /dev/null
+++ b/sys/syscall_pagedir.c
@@ -0,0 +1,112 @@
+#include "hal/memory.h"
+#include "jove.h"
+#include "lib/printf.h"
+#include "syscall.h"
+
+static int
+s_syscall_pagedir_map(
+        jove_owned_obj_t *objdir,
+        jove_owned_obj_t *target_obj,
+        size_t payload_bytes,
+        void *payload_data,
+        jove_owned_obj_t **untyped_ret)
+{
+    size_t bytes_needed = sizeof(struct syscall_pagedir_map);
+    CHECK_TOOSMALL(bytes_needed, payload_bytes,
+            "Message too small for payload.");
+
+    struct syscall_pagedir_map *payload = payload_data;
+    if(payload->virtual_address > 0xFFFF800000000000ULL) {
+        kprintf("%s: Virtual address is above user limit.\n", __func__);
+        return EBADARG;
+    }
+
+    bytes_needed += payload->untyped_pathlen << 1;
+    CHECK_TOOSMALL(bytes_needed, payload_bytes,
+            "Message too small for untyped path.");
+
+    errno = 0;
+    jove_owned_obj_t *untyped_obj = objdir_getobj(objdir,
+            payload->untyped_path, payload->untyped_pathlen);
+    if(errno) {
+        kprintf("%s: Untyped path does not point to a valid object.\n", __func__);
+        return errno;
+    }
+    
+    CHECK_OBJTYPE(untyped_obj, JOVE_OBJ_UNTYPED,
+            "Untyped path does not point to an untyped object.");
+    jove_untyped_t *untyped_data = obj_deref(untyped_obj);
+
+    if((uintptr_t)untyped_data & 0xFFF) {
+        kprintf("%s: Untyped object is not page aligned.\n", __func__);
+        obj_release(untyped_obj);
+        return EALIGN;
+    }
+    if(untyped_data->limit != 0x1000) {
+        kprintf("%s: Untyped object is not page sized.\n", __func__);
+        obj_release(untyped_obj);
+        return EBADSIZE;
+    }
+
+    *untyped_ret = untyped_obj;
+    return 0;
+}
+
+static int
+s_syscall_pagedir_map_frame(
+        jove_owned_obj_t *objdir,
+        jove_owned_obj_t *target_obj,
+        size_t payload_bytes,
+        void *payload_data)
+{
+    jove_owned_obj_t *untyped_obj = NULL;
+    int sysret = s_syscall_pagedir_map(objdir, target_obj, payload_bytes, payload_data, &untyped_obj);
+    if(sysret != 0) {
+        return sysret;
+    }
+
+    struct syscall_pagedir_map *payload = payload_data;
+    sysret = pagedir_map_frame(target_obj, untyped_obj, payload->virtual_address, payload->flags);
+    obj_release(untyped_obj);
+    return sysret;
+}
+
+static int
+s_syscall_pagedir_map_table(
+        jove_owned_obj_t *objdir,
+        jove_owned_obj_t *target_obj,
+        size_t payload_bytes,
+        void *payload_data)
+{
+    jove_owned_obj_t *untyped_obj = NULL;
+    int sysret = s_syscall_pagedir_map(objdir, target_obj, payload_bytes, payload_data, &untyped_obj);
+    if(sysret != 0) {
+        return sysret;
+    }
+
+    struct syscall_pagedir_map *payload = payload_data;
+    sysret = pagedir_map_frame(target_obj, untyped_obj, payload->virtual_address, payload->flags);
+    obj_release(untyped_obj);
+    return sysret;
+}
+
+int
+_syscall_handle_pagedir(
+        jove_owned_obj_t *pcb_obj,
+        jove_owned_obj_t *objdir,
+        jove_owned_obj_t *message_obj,
+        jove_owned_obj_t *target_obj,
+        struct syscall_header *header,
+        size_t bytes_left,
+        void *payload)
+{
+    switch(header->callid) {
+        case SYSCALL_PAGEDIR_MAP_FRAME:
+            return s_syscall_pagedir_map_frame(objdir, target_obj, bytes_left, payload);
+        case SYSCALL_PAGEDIR_MAP_TABLE:
+            return s_syscall_pagedir_map_table(objdir, target_obj, bytes_left, payload);
+        default:
+            kprintf("syscall_handle_pagedir: Pagedir does not support syscall %i\n", header->callid);
+            return EBADARG;
+    }
+}
-- 
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