sp1: mm: Add helpers to convert PMA-to-vma, etc

Signed-off-by: Ian Moffett <ian@mirocom.org>

usr/src/sp1/head/mm/vm.h

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2026, Mirocom Laboratories
+ * All rights reserved.
+ *
+ * The following sources are CONFIDENTIAL and PROPRIETARY
+ * property of Mirocom Laboratories. Unauthorized copying,
+ * use, distribution or modification of this file, in whole
+ * and in part, is strictly prohibited without the prior written
+ * consent from Mirocom Laboratories.
+ */
+
+#ifndef _MM_VM_H_
+#define _MM_VM_H_ 1
+
+#include <sys/param.h>
+#include <os/bpt.h>
+
+/*
+ * Macros used to convert physical to virtual addresses
+ * and vice versa.
+ */
+#define pma_to_vma(pma) \
+    PTR_OFFSET((void *)pma, bpt_kload_base())
+#define vma_to_pma(vma) \
+    (uintptr_t)PTR_NOFFSET(vma, bpt_kload_base())
+
+#endif  /* !_MM_VM_H_ */

usr/src/sp1/head/os/bpt.h

@@ -12,6 +12,7 @@
 #ifndef _OS_BPT_H_
 #define _OS_BPT_H_ 1
 
+#include <sys/cdefs.h>
 #include <sys/types.h>
 #include <sys/status.h>
 
@@ -83,4 +84,19 @@ status_t bpt_init(void);
 /* Boot protocol specific init funcs */
 status_t bpt_init_limine(struct bpt_ops *ops);
 
+/*
+ * Obtain the kernel load base from the bootloader
+ */
+__always_inline static inline uintptr_t
+bpt_kload_base(void)
+{
+    struct bpt_protovar pv;
+
+    if (bpt_get_protovar(&pv) != STATUS_SUCCESS) {
+        return 0;
+    }
+
+    return pv.kload_base;
+}
+
 #endif  /* !_OS_BPT_H_ */