[test] Allow self-tests to report exit status when running under Linux

Allow the return status from an embedded image to propagate out to the
eventual return status from main().  When running under Linux, this
allows the pass/fail result of unit tests to be observable without
having to visually inspect the console output.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/core/main.c

  * @ret rc		Return status code
  */
 __asmcall int main ( void ) {
+	int rc;
 
 	/* Perform one-time-only initialisation (e.g. heap) */
 	initialise();
 	startup();
 	printf ( "ok\n" );
 
-	ipxe ( NULL );
+	/* Attempt to boot */
+	if ( ( rc = ipxe ( NULL ) ) != 0 )
+		goto err_ipxe;
 
+ err_ipxe:
 	shutdown_exit();
-
-	return 0;
+	return rc;
 }

src/include/usr/autoboot.h

 extern struct uri *
 fetch_next_server_and_filename ( struct settings *settings );
 extern int netboot ( struct net_device *netdev );
-extern void ipxe ( struct net_device *netdev );
+extern int ipxe ( struct net_device *netdev );
 
 extern int pxe_menu_boot ( struct net_device *netdev );
 

src/interface/efi/efi_snp.c

 	struct efi_snp_device *snpdev =
 		container_of ( load_file, struct efi_snp_device, load_file );
 	struct net_device *netdev = snpdev->netdev;
+	int rc;
 
 	/* Fail unless this is a boot attempt */
 	if ( ! booting ) {
 	efi_watchdog_start();
 
 	/* Boot from network device */
-	ipxe ( netdev );
+	if ( ( rc = ipxe ( netdev ) ) != 0 )
+		goto err_ipxe;
 
-	/* Stop watchdog holdoff timer */
+ err_ipxe:
 	efi_watchdog_stop();
-
-	/* Release network devices for use via SNP */
 	efi_snp_release();
-
-	/* Assume boot process was aborted */
-	return EFI_ABORTED;
+	return EFIRC ( rc );
 }
 
 /** Load file protocol */

src/usr/autoboot.c

  * Main iPXE flow of execution
  *
  * @v netdev		Network device, or NULL
+ * @ret rc		Return status code
  */
-void ipxe ( struct net_device *netdev ) {
+int ipxe ( struct net_device *netdev ) {
 	struct feature *feature;
 	struct image *image;
 	char *scriptlet;
+	int rc;
 
 	/*
 	 * Print welcome banner
 	/* Boot system */
 	if ( ( image = first_image() ) != NULL ) {
 		/* We have an embedded image; execute it */
-		image_exec ( image );
+		return image_exec ( image );
 	} else if ( shell_banner() ) {
 		/* User wants shell; just give them a shell */
-		shell();
+		return shell();
 	} else {
 		fetch_string_setting_copy ( NULL, &scriptlet_setting,
 					    &scriptlet );
 		if ( scriptlet ) {
 			/* User has defined a scriptlet; execute it */
-			system ( scriptlet );
+			rc = system ( scriptlet );
 			free ( scriptlet );
+			return rc;
 		} else {
 			/* Try booting.  If booting fails, offer the
 			 * user another chance to enter the shell.
 			 */
 			if ( netdev ) {
-				netboot ( netdev );
+				rc = netboot ( netdev );
 			} else {
-				autoboot();
+				rc = autoboot();
 			}
 			if ( shell_banner() )
-				shell();
+				rc = shell();
+			return rc;
 		}
 	}
 }