U-Boot patch to exit userspace tools when an invalid CRC is found

0001-env-Exit-tools-when-invalid-CRC-found.patch

From 6482180e602c4853e43d5c5a40b3349b63aba276 Mon Sep 17 00:00:00 2001
From: Philip Molloy <philip-molloy@idexx.com>
Date: Tue, 2 Apr 2019 17:02:48 -0400
Subject: [PATCH 1/1] env: Exit tools when invalid CRC found

fw_setenv and fw_printenv currently print a warning and use a default
environment compiled into the binary when an invalid CRC is found. This
modifies the default behavior to print an error and exit. This is
especially important when calling the tools from a script since the 
script depends on the exit code of the tool to know something went
wrong.

If the default environment is desired it should be read explicitly by
the caller. A better model is to store a default environment as a
separate binary or text file rather than storing it in the executable.

Signed-off-by: Philip Molloy <philip-molloy@idexx.com>
---
 tools/env/fw_env.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/tools/env/fw_env.c b/tools/env/fw_env.c
index a5d75958e1..ef33e9e1be 100644
--- a/tools/env/fw_env.c
+++ b/tools/env/fw_env.c
@@ -1438,9 +1438,8 @@ int fw_env_open(struct env_opts *opts)
    if (!have_redund_env) {
        if (!crc0_ok) {
            fprintf(stderr,
-               "Warning: Bad CRC, using default environment\n");
-           memcpy(environment.data, default_environment,
-                  sizeof(default_environment));
+               "Invalid CRC found in environment\n");
+           return -1;
        }
    } else {
        flag0 = *environment.flags;
@@ -1500,10 +1499,8 @@ int fw_env_open(struct env_opts *opts)
            dev_current = 1;
        } else if (!crc0_ok && !crc1_ok) {
            fprintf(stderr,
-               "Warning: Bad CRC, using default environment\n");
-           memcpy(environment.data, default_environment,
-                  sizeof(default_environment));
-           dev_current = 0;
+               "Invalid CRC found in both redundant environments\n");
+           return -1;
        } else {
            switch (environment.flag_scheme) {
            case FLAG_BOOLEAN:
-- 
2.20.1