stos: vmm: Initialize virtual memory manager

Signed-off-by: Chloe M. <chloe@mensia.org>

paw/stos/head/mm/vmm.h

@@ -19,4 +19,9 @@
 #define VMA_TO_PMA(VMA) \
     (UPTR)PTR_NOFFSET(VMA, KeBpalLoadBase())
 
+/*
+ * Initialize the virtual memory manager
+ */
+VOID MmInitVmm(VOID);
+
 #endif  /* !_MM_VMM_H_ */

paw/stos/init/init.c

@@ -13,6 +13,7 @@
 #include <hal/kpcr.h>
 #include <drivers/bootvid/fbio.h>
 #include <mm/pmm.h>
+#include <mm/vmm.h>
 #include <stdef.h>
 
 #define DTRACE(Fmt, ...) \
@@ -52,6 +53,9 @@ KiKernelEntry(VOID)
     /* Initialize physical memory */
     MmInitPmm();
 
+    /* Initialize virtual memory */
+    MmInitVmm();
+
     /* Phase 1 initialization the bootstrap core */
     HalKpcrP1Init(&BootstrapCore);
 }

paw/stos/mm/vmm.c

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2026, Chloe M.
+ * Provided under the BSD-3 clause.
+ *
+ * Description:  Virtual memory manager
+ * Author:       Chloe M.
+ */
+
+#include <mm/vmm.h>
+#include <hal/mmu.h>
+#include <ex/trace.h>
+
+#define DTRACE(Fmt, ...) \
+    TRACE("[ VMM ]: " Fmt, ##__VA_ARGS__)
+
+static MMU_VAS KernelVas;
+
+VOID
+MmInitVmm(VOID)
+{
+    MMU_VAS OldVas;
+    ST_STATUS Status;
+
+    DTRACE("breeding kvas from bootstrap instance...\n");
+    HalMmuReadVas(&OldVas);
+    Status = HalMmuForkVas(&OldVas, &KernelVas);
+
+    if (Status != STATUS_SUCCESS) {
+        /* TODO: Panic here */
+        return;
+    }
+
+    HalMmuWriteVas(&KernelVas);
+    DTRACE("ah!~... [ok @ %p]\n", VAS_BASE(&KernelVas));
+}