Implement memory space lifecycle management

Add functions to create and destroy memory spaces, which serve as
containers for flexpages. A memory space can be dedicated to a single
task or shared across multiple tasks, supporting both isolated and
shared memory models.

Author: HeatCrab

include/sys/memprot.h

@@ -91,3 +91,17 @@ fpage_t *mo_fpage_create(uint32_t base,
  * @fpage : Pointer to flexpage to destroy
  */
 void mo_fpage_destroy(fpage_t *fpage);
+
+/* Memory Space Management Functions */
+
+/* Creates and initializes a memory space.
+ * @as_id : Memory space identifier
+ * @shared : Whether this space can be shared across tasks
+ * Returns pointer to created memory space, or NULL on failure.
+ */
+memspace_t *mo_memspace_create(uint32_t as_id, uint32_t shared);
+
+/* Destroys a memory space and all its flexpages.
+ * @mspace : Pointer to memory space to destroy
+ */
+void mo_memspace_destroy(memspace_t *mspace);

kernel/memprot.c

@@ -127,3 +127,44 @@ int32_t pmp_evict_fpage(fpage_t *fpage)
 
     return ret;
 }
+
+/* Creates and initializes a memory space.
+ *
+ * @as_id : Memory space identifier
+ * @shared : Whether this space can be shared across tasks
+ * Returns pointer to created memory space, or NULL on failure.
+ */
+memspace_t *mo_memspace_create(uint32_t as_id, uint32_t shared)
+{
+    memspace_t *mspace = malloc(sizeof(memspace_t));
+    if (!mspace)
+        return NULL;
+
+    mspace->as_id = as_id;
+    mspace->first = NULL;
+    mspace->pmp_first = NULL;
+    mspace->pmp_stack = NULL;
+    mspace->shared = shared;
+
+    return mspace;
+}
+
+/* Destroys a memory space and all its flexpages.
+ *
+ * @mspace : Pointer to memory space to destroy
+ */
+void mo_memspace_destroy(memspace_t *mspace)
+{
+    if (!mspace)
+        return;
+
+    /* Free all flexpages in the list */
+    fpage_t *fp = mspace->first;
+    while (fp) {
+        fpage_t *next = fp->as_next;
+        mo_fpage_destroy(fp);
+        fp = next;
+    }
+
+    free(mspace);
+}