[PATCH v2 8/8] 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 | 11 +++++------
 common/spl/spl_nor.c  | 10 +++++-----
 common/spl/spl_spi.c  |  3 +++
 common/spl/spl_ubi.c  |  2 ++
 5 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/common/spl/spl_mmc.c b/common/spl/spl_mmc.c
index e26f1087d45..c9637399c15 100644
--- a/common/spl/spl_mmc.c
+++ b/common/spl/spl_mmc.c
@@ -270,6 +270,8 @@ static int spl_mmc_do_fs_boot(struct spl_image_info *spl_image,
 					 mmc_get_blk_desc(mmc), partition);
 		if (!ret)
 			return 0;
+		if (CONFIG_IS_ENABLED(OS_BOOT_SECURE))
+			return ret;
 	}
 
 #ifdef CONFIG_SPL_FS_LOAD_PAYLOAD_NAME
@@ -409,6 +411,8 @@ 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 (CONFIG_IS_ENABLED(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 8993e304c26..7d1b55b2311 100644
--- a/common/spl/spl_nand.c
+++ b/common/spl/spl_nand.c
@@ -138,12 +138,11 @@ 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;
-		} else {
-			puts("The Expected Linux image was not "
-				"found. Please check your NAND "
-				"configuration.\n");
-			puts("Trying to start u-boot now...\n");
-		}
+
+		puts("%s: Failed in falcon boot: %d", __func__, err);
+		if (CONFIG_IS_ENABLED(OS_BOOT_SECURE))
+			return err;
+		puts("Fallback to U-Boot\n");
 	}
 #endif
 
diff --git a/common/spl/spl_nor.c b/common/spl/spl_nor.c
index e999dcc4fcf..6f8149cac53 100644
--- a/common/spl/spl_nor.c
+++ b/common/spl/spl_nor.c
@@ -94,11 +94,11 @@ static int spl_nor_load_image(struct spl_image_info *spl_image,
 		err = spl_nor_load_image_os(spl_image, bootdev);
 		if (!err)
 			return 0;
-		} else {
-			puts("The Expected Linux image was not found.\n"
-			     "Please check your NOR configuration.\n"
-			     "Trying to start u-boot now...\n");
-		}
+
+		puts("%s: Failed in falcon boot: %d", __func__, err);
+		if (CONFIG_IS_ENABLED(OS_BOOT_SECURE))
+			return err;
+		puts("Fallback to U-Boot\n");
 	}
 #endif
 
diff --git a/common/spl/spl_spi.c b/common/spl/spl_spi.c
index 1ada37f5c21..863be144316 100644
--- a/common/spl/spl_spi.c
+++ b/common/spl/spl_spi.c
@@ -104,6 +104,9 @@ static int spl_spi_load_image(struct spl_image_info *spl_image,
 
 		if (!err)
 			return 0;
+
+		if (CONFIG_IS_ENABLED(OS_BOOT_SECURE))
+			return err;
 	}
 #endif
 
diff --git a/common/spl/spl_ubi.c b/common/spl/spl_ubi.c
index 162ec0f2f9b..95676975e76 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;
 
 		puts("Loading Linux failed, falling back to U-Boot.\n");
+		if (CONFIG_IS_ENABLED(OS_BOOT_SECURE))
+			return ret;
 	}
 #endif
 
-- 
2.51.0