spawn: Setup dispatcher

lib/spawn/spawn.c

@@ -210,7 +210,51 @@ errval_t spawn_load_argv(int argc, char *argv[], struct spawninfo *si,
     }
 
     // - Setup the dispatcher
-    // TODO
+    err = frame_create(si->cspace_cap_dispframe, DISPATCHER_FRAME_SIZE, NULL);
+    if (err_is_fail(err)) {
+        return err_push(err, SPAWN_ERR_CREATE_DISPATCHER_FRAME);
+    }
+
+    dispatcher_handle_t handle;
+    err = paging_map_frame_attr(
+        get_current_paging_state(), (void **)&handle,
+        DISPATCHER_FRAME_SIZE, si->cspace_cap_dispframe, VREGION_FLAGS_READ_WRITE
+    );
+    if (err_is_fail(err)) return err;
+
+    struct dispatcher_shared_generic *disp =
+        get_dispatcher_shared_generic(handle);
+
+    struct dispatcher_generic *disp_gen = get_dispatcher_generic(handle);
+
+    arch_registers_state_t *enabled_area =
+        dispatcher_get_enabled_save_area(handle);
+
+    arch_registers_state_t *disabled_area =
+        dispatcher_get_disabled_save_area(handle);
+
+    // core id of the process
+    disp_gen->core_id = disp_get_core_id();
+    // Virtual address of the dispatcher frame in child's VSpace
+    disp->udisp = 0; // TODO
+    // Start in disabled mode
+    disp->disabled = 1;
+    // A name (for debugging)
+    strncpy(disp->name, argv[0], DISP_NAME_LEN);
+    // Set program counter (where it should start to execute)
+    disabled_area->named.pc = entry;
+
+    // Initialize offset registers
+    // got_addr is the address of the .got in the child's VSpace
+    armv8_set_registers((void *)got_addr, handle, enabled_area, disabled_area);
+
+    // we won't use error handling frames
+    disp_gen->eh_frame = 0;
+    disp_gen->eh_frame_size = 0;
+    disp_gen->eh_frame_hdr = 0;
+    disp_gen->eh_frame_hdr_size = 0;
+
+    // TODO: Map dispatcher frame into child address space
 
     // - Setup the environment
     // TODO