[PATCH v4 7/7] spl: falcon: disable fallback to U-Boot on failure

[Anshul Dalal]

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 at ti.com>
---
 common/spl/spl_mmc.c  | 4 ++++
 common/spl/spl_nand.c | 6 ++++--
 common/spl/spl_nor.c  | 6 ++++--
 common/spl/spl_spi.c  | 6 ++++--
 common/spl/spl_ubi.c  | 2 ++
 5 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/common/spl/spl_mmc.c b/common/spl/spl_mmc.c
index bfcdea2d05f..0a00d295575 100644
--- a/common/spl/spl_mmc.c
+++ b/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);
diff --git a/common/spl/spl_nand.c b/common/spl/spl_nand.c
index c9f5d039768..3da292f1437 100644
--- a/common/spl/spl_nand.c
+++ b/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
 
diff --git a/common/spl/spl_nor.c b/common/spl/spl_nor.c
index c349a4c7bc3..bb91f4ab8f8 100644
--- a/common/spl/spl_nor.c
+++ b/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
 
diff --git a/common/spl/spl_spi.c b/common/spl/spl_spi.c
index 45718824cbf..4d61214bceb 100644
--- a/common/spl/spl_spi.c
+++ b/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
 
diff --git a/common/spl/spl_ubi.c b/common/spl/spl_ubi.c
index 4aecad3470c..25e7599703c 100644
--- a/common/spl/spl_ubi.c
+++ b/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
-- 
2.51.0