Extract UVISOR_BOX_ID_INVALID to vmpu.h

Author: niklarm

api/inc/vmpu_exports.h

@@ -27,6 +27,9 @@
  * terminating NULL. */
 #define UVISOR_MAX_BOX_NAMESPACE_LENGTH 37
 
+/** Invalid box id for use in marking objects with invalid ownership. */
+#define UVISOR_BOX_ID_INVALID ((uint8_t) -1)
+
 /* supervisor user access modes */
 #define UVISOR_TACL_UEXECUTE        0x0001UL
 #define UVISOR_TACL_UWRITE          0x0002UL

core/system/inc/page_allocator_config.h

@@ -44,8 +44,6 @@
 
 /* The page box_id is the box id which is 8-bit large. */
 typedef uint8_t page_owner_t;
-/* Define a unused value for the page table. */
-#define UVISOR_PAGE_UNUSED ((page_owner_t) (-1))
 /* Contains the total number of available pages. */
 extern uint8_t g_page_count_total;
 /* Contains the shift of the page owner mask. */

core/system/src/page_allocator.c

@@ -36,6 +36,7 @@
  * SVC call, which automagically serializes access to it. */
 #define UVISOR_PAGE_ALLOCATOR_MUTEX_AQUIRE  {}
 #define UVISOR_PAGE_ALLOCATOR_MUTEX_RELEASE {}
+#define UVISOR_PAGE_UNUSED UVISOR_BOX_ID_INVALID
 
 #endif /* defined(UVISOR_PRESENT) && (UVISOR_PRESENT == 1) */
 
@@ -73,12 +74,6 @@ uint8_t page_allocator_get_page_from_address(uint32_t address)
 
 void page_allocator_init(void * const heap_start, void * const heap_end, const uint32_t * const page_size)
 {
-    /* Make sure the UVISOR_PAGE_UNUSED is definitely NOT a valid box id. */
-    if (vmpu_is_box_id_valid(UVISOR_PAGE_UNUSED)) {
-        HALT_ERROR(SANITY_CHECK_FAILED,
-            "UVISOR_PAGE_UNUSED (%u) must not be a valid box id!\n",
-            UVISOR_PAGE_UNUSED);
-    }
     if (!page_size || !vmpu_public_flash_addr((uint32_t) page_size)) {
         HALT_ERROR(SANITY_CHECK_FAILED,
             "Page size pointer (0x%08x) is not in flash memory.\n",

core/system/src/page_allocator_faults.c

@@ -16,13 +16,15 @@
  */
 
 #include <uvisor.h>
+#include "api/inc/vmpu_exports.h"
 #include "page_allocator.h"
 #include "page_allocator_faults.h"
 #include "page_allocator_config.h"
 #include "context.h"
 
 /* Maps the number of faults to a page. */
 uint32_t g_page_fault_table[UVISOR_PAGE_MAX_COUNT];
+#define UVISOR_PAGE_UNUSED UVISOR_BOX_ID_INVALID
 
 void page_allocator_reset_faults(uint8_t page)
 {

core/vmpu/src/vmpu.c

@@ -43,6 +43,13 @@ static int vmpu_sanity_checks(void)
             &__uvisor_config, __uvisor_config.magic, UVISOR_MAGIC);
     }
 
+    /* Make sure the UVISOR_BOX_ID_INVALID is definitely NOT a valid box id. */
+    if (vmpu_is_box_id_valid(UVISOR_BOX_ID_INVALID)) {
+        HALT_ERROR(SANITY_CHECK_FAILED,
+            "UVISOR_BOX_ID_INVALID (%u) must not be a valid box id!\n",
+            UVISOR_BOX_ID_INVALID);
+    }
+
     /* Verify basic assumptions about vmpu_bits/__builtin_clz. */
     assert(__builtin_clz(0) == 32);
     assert(__builtin_clz(1UL << 31) == 0);