U-Boot patch to load a redundant environment from EEPROM

0001-Load-a-redundant-environment-from-EEPROM.patch

From e95f003a96096f7d8602ad2edaf1dd0bf4e27c45 Mon Sep 17 00:00:00 2001
From: Philip Molloy <philip@philipmolloy.com>
Date: Wed, 28 Aug 2019 21:05:11 -0400
Subject: [PATCH] Load a redundant environment from EEPROM

---
 env/eeprom.c | 128 +++++++++++++--------------------------------------
 1 file changed, 31 insertions(+), 97 deletions(-)

diff --git a/env/eeprom.c b/env/eeprom.c
index ac2689cc14..98ba672202 100644
--- a/env/eeprom.c
+++ b/env/eeprom.c
@@ -78,114 +78,48 @@ int env_eeprom_get_char(int index)
 	return c;
 }
 
+#ifdef CONFIG_ENV_OFFSET_REDUND
 static int env_eeprom_load(void)
 {
-	char buf_env[CONFIG_ENV_SIZE];
-	unsigned int off = CONFIG_ENV_OFFSET;
+	int read1_ret, read2_ret;
+	// TODO(PM): Dynamically allocate using memalign()
+	char buf1[CONFIG_ENV_SIZE];
+	char buf2[CONFIG_ENV_SIZE];
 
-#ifdef CONFIG_ENV_OFFSET_REDUND
-	ulong len, crc[2], crc_tmp;
-	unsigned int off_env[2];
-	uchar rdbuf[64], flags[2];
-	int i, crc_ok[2] = {0, 0};
-
-	eeprom_init(-1);	/* prepare for EEPROM read/write */
-
-	off_env[0] = CONFIG_ENV_OFFSET;
-	off_env[1] = CONFIG_ENV_OFFSET_REDUND;
-
-	for (i = 0; i < 2; i++) {
-		/* read CRC */
-		eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
-				off_env[i] + offsetof(env_t, crc),
-				(uchar *)&crc[i], sizeof(ulong));
-		/* read FLAGS */
-		eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
-				off_env[i] + offsetof(env_t, flags),
-				(uchar *)&flags[i], sizeof(uchar));
-
-		crc_tmp = 0;
-		len = ENV_SIZE;
-		off = off_env[i] + offsetof(env_t, data);
-		while (len > 0) {
-			int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
-
-			eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
-					rdbuf, n);
-
-			crc_tmp = crc32(crc_tmp, rdbuf, n);
-			len -= n;
-			off += n;
-		}
-
-		if (crc_tmp == crc[i])
-			crc_ok[i] = 1;
-	}
+	eeprom_init(-1);
 
-	if (!crc_ok[0] && !crc_ok[1]) {
-		gd->env_addr	= 0;
-		gd->env_valid = ENV_INVALID;
-	} else if (crc_ok[0] && !crc_ok[1]) {
-		gd->env_valid = ENV_VALID;
-	} else if (!crc_ok[0] && crc_ok[1]) {
-		gd->env_valid = ENV_REDUND;
-	} else {
-		/* both ok - check serial */
-		if (flags[0] == ACTIVE_FLAG && flags[1] == OBSOLETE_FLAG)
-			gd->env_valid = ENV_VALID;
-		else if (flags[0] == OBSOLETE_FLAG && flags[1] == ACTIVE_FLAG)
-			gd->env_valid = ENV_REDUND;
-		else if (flags[0] == 0xFF && flags[1] == 0)
-			gd->env_valid = ENV_REDUND;
-		else if (flags[1] == 0xFF && flags[0] == 0)
-			gd->env_valid = ENV_VALID;
-		else /* flags are equal - almost impossible */
-			gd->env_valid = ENV_VALID;
-	}
+	read1_ret = eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
+				    CONFIG_ENV_OFFSET,
+				    (uchar *)&buf1,
+				    CONFIG_ENV_SIZE);
 
-#else /* CONFIG_ENV_OFFSET_REDUND */
-	ulong crc, len, new;
-	uchar rdbuf[64];
-
-	eeprom_init(-1);	/* prepare for EEPROM read/write */
-
-	/* read old CRC */
-	eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
-			CONFIG_ENV_OFFSET + offsetof(env_t, crc),
-			(uchar *)&crc, sizeof(ulong));
-
-	new = 0;
-	len = ENV_SIZE;
-	off = offsetof(env_t, data);
-	while (len > 0) {
-		int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
-
-		eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
-				CONFIG_ENV_OFFSET + off, rdbuf, n);
-		new = crc32(new, rdbuf, n);
-		len -= n;
-		off += n;
-	}
+	read2_ret = eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
+				    CONFIG_ENV_OFFSET_REDUND,
+				    (uchar *)&buf2,
+				    CONFIG_ENV_SIZE);
 
-	if (crc == new) {
-		gd->env_valid = ENV_VALID;
-	} else {
-		gd->env_valid = ENV_INVALID;
-	}
-#endif /* CONFIG_ENV_OFFSET_REDUND */
+	return env_import_redund(buf1, read1_ret, buf2, read2_ret);
+}
+#else
+static int env_eeprom_load(void)
+{
+	int ret;
+	char buf[CONFIG_ENV_SIZE];
 
-	off = CONFIG_ENV_OFFSET;
-#ifdef CONFIG_ENV_OFFSET_REDUND
-	if (gd->env_valid == ENV_REDUND)
-		off = CONFIG_ENV_OFFSET_REDUND;
-#endif
+	eeprom_init(-1);
 
-	eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
-		off, (uchar *)buf_env, CONFIG_ENV_SIZE);
+	ret = eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
+			      CONFIG_ENV_OFFSET,
+			      (uchar *)&buf,
+			      CONFIG_ENV_SIZE);
+	// TODO(PM): Handle return value
 
-	return env_import(buf_env, 1);
+	return env_import(buf, 1);
 }
+#endif /* CONFIG_ENV_OFFSET_REDUND */
+
 
+// TODO(PM): Review this for changes since env/sf.c has two implementations
 static int env_eeprom_save(void)
 {
 	env_t	env_new;
-- 
2.17.2