spl: falcon: disable fallback to U-Boot on failure

Instead of falling back to the standard U-Boot boot flow, we should just
halt boot if the expected boot flow in falcon mode fails.

This prevents a malicious actor from accessing U-Boot proper if they can
cause a boot failure on falcon mode.

Signed-off-by: Anshul Dalal <anshuld@ti.com>

common/spl/spl_mmc.c

@@ -272,6 +272,8 @@ static int spl_mmc_do_fs_boot(struct spl_image_info *spl_image,
 			return 0;
 		printf("%s, Failed to load falcon payload: %d\n", __func__,
 		       ret);
+		if (IS_ENABLED(CONFIG_SPL_OS_BOOT_SECURE))
+			return ret;
 		printf("Fallback to U-Boot\n");
 	}
 
@@ -412,6 +414,8 @@ int spl_mmc_load(struct spl_image_info *spl_image,
 			ret = mmc_load_image_raw_os(spl_image, bootdev, mmc);
 			if (!ret)
 				return 0;
+			if (IS_ENABLED(CONFIG_SPL_OS_BOOT_SECURE))
+				return ret;
 		}
 
 		raw_sect = spl_mmc_get_uboot_raw_sector(mmc, raw_sect);

common/spl/spl_nand.c

@@ -138,8 +138,10 @@ static int spl_nand_load_image(struct spl_image_info *spl_image,
 		err = spl_nand_load_image_os(spl_image, bootdev);
 		if (!err)
 			return 0;
-		printf("%s: Failed in falcon boot: %d, fallback to U-Boot",
-		       __func__, err);
+		printf("%s: Failed in falcon boot: %d", __func__, err);
+		if (IS_ENABLED(CONFIG_SPL_OS_BOOT_SECURE))
+			return err;
+		printf("Fallback to U-Boot\n");
 	}
 #endif
 

common/spl/spl_nor.c

@@ -96,8 +96,10 @@ static int spl_nor_load_image(struct spl_image_info *spl_image,
 		if (!err)
 			return 0;
 
-		printf("%s: Failed in falcon boot: %d, fallback to U-Boot",
-		       __func__, err);
+		printf("%s: Failed in falcon boot: %d", __func__, err);
+		if (IS_ENABLED(CONFIG_SPL_OS_BOOT_SECURE))
+			return err;
+		printf("Fallback to U-Boot\n");
 	}
 #endif
 

common/spl/spl_spi.c

@@ -105,8 +105,10 @@ static int spl_spi_load_image(struct spl_image_info *spl_image,
 		if (!err)
 			return 0;
 
-		printf("%s: Failed in falcon boot: %d, fallback to U-Boot",
-		       __func__, err);
+		printf("%s: Failed in falcon boot: %d", __func__, err);
+		if (IS_ENABLED(CONFIG_SPL_OS_BOOT_SECURE))
+			return err;
+		printf("Fallback to U-Boot\n");
 	}
 #endif
 

common/spl/spl_ubi.c

@@ -77,6 +77,8 @@ int spl_ubi_load_image(struct spl_image_info *spl_image,
 			return 0;
 
 		printf("%s: Failed in falcon boot: %d", __func__, ret);
+		if (IS_ENABLED(CONFIG_SPL_OS_BOOT_SECURE))
+			return ret;
 		printf("Fallback to U-Boot\n");
 	}
 #endif