From 1577811d579f1aa8213c62f7bfac3e94f500a0d6 Mon Sep 17 00:00:00 2001
From: "Michael J. Chudobiak" <mjc@avtechpulse.com>
Date: Wed, 22 Aug 2012 10:42:05 -0400
Subject: fixes initialization of flash files

---
 flash.c | 52 ++++++++++++++++++++++++++++++++--------------------
 1 file changed, 32 insertions(+), 20 deletions(-)

(limited to 'flash.c')

diff --git a/flash.c b/flash.c
index 3113388..719b4b1 100644
--- a/flash.c
+++ b/flash.c
@@ -27,7 +27,8 @@
 
 // crc32 routine
 
-static uint32_t crc32(uint8_t* buf, int count) {
+static uint32_t crc32(uint8_t* buf, int count)
+{
 	MHASH context = mhash_init(MHASH_CRC32B);
 	mhash(context, buf, count);
 	uint32_t hash;
@@ -42,19 +43,23 @@ typedef struct {
 	uint32_t crc32;
 } persistancehdr;
 
-static void persistance_printheader(persistancehdr* hdr) {
-printf("Frozen struct has version %d, is %d bytes long and has the CRC32 0x%08"PRIx32"\n", hdr->version,
-		hdr->length, hdr->crc32);
+static void persistance_printheader(persistancehdr* hdr)
+{
+	printf("Frozen struct has version %d, is %d bytes long and has the CRC32 0x%08"PRIx32"\n", hdr->version,
+	       hdr->length, hdr->crc32);
 }
 
 // copy a file from one place to another.. this is not portable, linux only
-bool persistance_copyfile(char* source, char* dest) {
+bool persistance_copyfile(char* source, char* dest)
+{
 	mode_t filemode = S_IRUSR | S_IWUSR;
-	int src = open(source, O_RDONLY);
+	int src = open(source, O_RDONLY | O_CREAT); // should create the file for us if this is the first run
+	// You would think that O_RDONLY would stop the file creation, but it seems to work
 	int dst = open(dest, O_SYNC | O_RDWR | O_CREAT, filemode);
 
-	if (src < 0 || dst < 0)
+	if (src < 0 || dst < 0) {
 		return false;
+	}
 
 	struct stat s;
 	fstat(src, &s);
@@ -68,7 +73,8 @@ bool persistance_copyfile(char* source, char* dest) {
 
 // store an object
 bool persistance_freeze(char* dest, void* data, unsigned int offset, unsigned int len, unsigned int total,
-		uint32_t version) {
+                        uint32_t version)
+{
 
 	// don't write past the end of the file..
 	if (offset + len > total) {
@@ -151,7 +157,7 @@ bool persistance_freeze(char* dest, void* data, unsigned int offset, unsigned in
 
 	// write the data to disk
 	ftruncate(fd, sizeof(hdr) + total); // not really needed but if we did have a file thats bigger than it
-										// should be put a stop to that
+	// should be put a stop to that
 
 	// write the header
 	if (write(fd, &hdr, sizeof(hdr)) != sizeof(hdr)) {
@@ -162,7 +168,7 @@ bool persistance_freeze(char* dest, void* data, unsigned int offset, unsigned in
 	// seek to the offset.. which could mean not seeking at all
 	if (lseek(fd, offset, SEEK_CUR) < 0) {
 		errno = PERSIST_ERR_COULDNTSEEK; // shouldn't ever happen really because if we're actually
-										 // seeking the file should already be the total size.
+		// seeking the file should already be the total size.
 		return false;
 	}
 
@@ -180,7 +186,8 @@ bool persistance_freeze(char* dest, void* data, unsigned int offset, unsigned in
 }
 
 // try to load an object from disk
-bool persistance_unfreeze(char* dest, void* result, unsigned int len, uint32_t version) {
+bool persistance_unfreeze(char* dest, void* result, unsigned int len, uint32_t version)
+{
 
 	int fd = open(dest, O_RDONLY);
 
@@ -225,11 +232,13 @@ bool persistance_unfreeze(char* dest, void* result, unsigned int len, uint32_t v
 
 }
 
-int readUserBlock(FlashStruct *mem) {
+int readUserBlock(FlashStruct *mem)
+{
 
 	// try to unfreeze the main file
-	if (persistance_unfreeze(MAINFILE, mem, sizeof(*mem), 0))
+	if (persistance_unfreeze(MAINFILE, mem, sizeof(*mem), 0)) {
 		return sizeof(*mem);
+	}
 	// something went wrong
 	else {
 		printf("Error unfreezing %d.. trying backup\n", errno);
@@ -247,7 +256,8 @@ int readUserBlock(FlashStruct *mem) {
 	return 0;
 }
 
-void writeUserBlock(FlashStruct *mem, int addr, int numbytes) {
+void writeUserBlock(FlashStruct *mem, int addr, int numbytes)
+{
 
 	// *** There is a potential issue here.. if the mainfile is corrupt ***
 	// *** and this gets called before readUserBlock then the 			***
@@ -258,20 +268,22 @@ void writeUserBlock(FlashStruct *mem, int addr, int numbytes) {
 	// backup the main copy of the file
 	if (persistance_copyfile(MAINFILE, BACKUPFILE)) {
 		if (!persistance_freeze(MAINFILE, mem, addr, numbytes, sizeof(*mem), 0)) {
-			if (errno != PERSIST_ERR_COULDNTWRITE)
+			if (errno != PERSIST_ERR_COULDNTWRITE) {
 				printf("Error while trying to write, %d. **Write did not happen!!!**\n", errno);
-			else
+			} else {
 				printf("Error while writing data to disk. **File is potentially corrupt!**\n");
+			}
 		}
-	}
-	else {
+	} else {
 		printf("Could not backup current file. **Write did not happen!!!**\n");
 	}
 }
 
-void initFlash(FlashStruct *mem) {
-	if (readUserBlock(mem) > 0)
+void initFlash(FlashStruct *mem)
+{
+	if (readUserBlock(mem) > 0) {
 		return;
+	}
 
 // uninitialized device!
 	mem->flash_start = (char) 99;
-- 
cgit