From: Arne Fitzenreiter <arne_f@ipfire.org>
Date: Wed, 16 Mar 2016 21:58:21 +0000 (+0100)
Subject: u-boot: fix fat16 reader
X-Git-Tag: v2.19-core100~8
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8649a31ed040795b09228c8f3fa181d001614541;p=ipfire-2.x.git

u-boot: fix fat16 reader
---

diff --git a/lfs/u-boot b/lfs/u-boot
index 28f65083cf..3b3fbf2211 100644
--- a/lfs/u-boot
+++ b/lfs/u-boot
@@ -75,6 +75,8 @@ $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects))
 	@$(PREBUILD)
 	@rm -rf $(DIR_APP) && cd $(DIR_SRC) && tar axf $(DIR_DL)/$(DL_FILE)
 
+	cd $(DIR_APP) && patch -Np1 < $(DIR_SRC)/src/patches/U-Boot-v2-fs-fat-read-fix-fat16-ls-read-issue.patch
+
 	# Pandaboard
 	-mkdir -pv /usr/share/u-boot/pandaboard
 	cd $(DIR_APP) && make CROSS_COMPILE="" omap4_panda_config
diff --git a/src/patches/U-Boot-v2-fs-fat-read-fix-fat16-ls-read-issue.patch b/src/patches/U-Boot-v2-fs-fat-read-fix-fat16-ls-read-issue.patch
new file mode 100644
index 0000000000..39acf14bd2
--- /dev/null
+++ b/src/patches/U-Boot-v2-fs-fat-read-fix-fat16-ls-read-issue.patch
@@ -0,0 +1,128 @@
+diff --git a/fs/fat/fat.c b/fs/fat/fat.c
+index 04a51db..bccc3e3 100644
+--- a/fs/fat/fat.c
++++ b/fs/fat/fat.c
+@@ -823,8 +823,11 @@ int do_fat_read_at(const char *filename, loff_t pos, void *buffer,
+ 	int ret = -1;
+ 	int firsttime;
+ 	__u32 root_cluster = 0;
++	__u32 read_blk;
+ 	int rootdir_size = 0;
+-	int j;
++	int buffer_blk_cnt;
++	int do_read;
++	__u8 *dir_ptr;
+ 
+ 	if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
+ 		debug("Error: reading boot sector\n");
+@@ -909,24 +912,54 @@ int do_fat_read_at(const char *filename, loff_t pos, void *buffer,
+ 		isdir = 1;
+ 	}
+ 
+-	j = 0;
++	buffer_blk_cnt = 0;
++	firsttime = 1;
+ 	while (1) {
+ 		int i;
+ 
+-		if (j == 0) {
+-			debug("FAT read sect=%d, clust_size=%d, DIRENTSPERBLOCK=%zd\n",
+-				cursect, mydata->clust_size, DIRENTSPERBLOCK);
++		if (mydata->fatsize == 32 || firsttime) {
++			dir_ptr = do_fat_read_at_block;
++			firsttime = 0;
++		} else {
++			/**
++			 * FAT16 sector buffer modification:
++			 * Each loop, the second buffered block is moved to
++			 * the buffer begin, and two next sectors are read
++			 * next to the previously moved one. So the sector
++			 * buffer keeps always 3 sectors for fat16.
++			 * And the current sector is the buffer second sector
++			 * beside the "firsttime" read, when it is the first one.
++			 *
++			 * PREFETCH_BLOCKS is 2 for FAT16 == loop[0:1]
++			 * n = computed root dir sector
++			 * loop |  cursect-1  | cursect    | cursect+1  |
++			 *   0  |  sector n+0 | sector n+1 | none       |
++			 *   1  |  none       | sector n+0 | sector n+1 |
++			 *   0  |  sector n+1 | sector n+2 | sector n+3 |
++			 *   1  |  sector n+3 | ...
++			*/
++			dir_ptr = (do_fat_read_at_block + mydata->sect_size);
++			memcpy(do_fat_read_at_block, dir_ptr, mydata->sect_size);
++		}
++
++		do_read = 1;
++
++		if (mydata->fatsize == 32 && buffer_blk_cnt)
++			do_read = 0;
++
++		if (do_read) {
++			read_blk = (mydata->fatsize == 32) ?
++				    mydata->clust_size : PREFETCH_BLOCKS;
++
++			debug("FAT read(sect=%d, cnt:%d), clust_size=%d, DIRENTSPERBLOCK=%zd\n",
++				cursect, read_blk, mydata->clust_size, DIRENTSPERBLOCK);
+ 
+-			if (disk_read(cursect,
+-					(mydata->fatsize == 32) ?
+-					(mydata->clust_size) :
+-					PREFETCH_BLOCKS,
+-					do_fat_read_at_block) < 0) {
++			if (disk_read(cursect, read_blk, dir_ptr) < 0) {
+ 				debug("Error: reading rootdir block\n");
+ 				goto exit;
+ 			}
+ 
+-			dentptr = (dir_entry *) do_fat_read_at_block;
++			dentptr = (dir_entry *)dir_ptr;
+ 		}
+ 
+ 		for (i = 0; i < DIRENTSPERBLOCK; i++) {
+@@ -951,7 +984,7 @@ int do_fat_read_at(const char *filename, loff_t pos, void *buffer,
+ 
+ 					get_vfatname(mydata,
+ 						     root_cluster,
+-						     do_fat_read_at_block,
++						     dir_ptr,
+ 						     dentptr, l_name);
+ 
+ 					if (dols == LS_ROOT) {
+@@ -1062,7 +1095,7 @@ int do_fat_read_at(const char *filename, loff_t pos, void *buffer,
+ 
+ 			goto rootdir_done;	/* We got a match */
+ 		}
+-		debug("END LOOP: j=%d   clust_size=%d\n", j,
++		debug("END LOOP: buffer_blk_cnt=%d   clust_size=%d\n", buffer_blk_cnt,
+ 		       mydata->clust_size);
+ 
+ 		/*
+@@ -1070,10 +1103,10 @@ int do_fat_read_at(const char *filename, loff_t pos, void *buffer,
+ 		 * root directory clusters when a cluster has been
+ 		 * completely processed.
+ 		 */
+-		++j;
++		++buffer_blk_cnt;
+ 		int rootdir_end = 0;
+ 		if (mydata->fatsize == 32) {
+-			if (j == mydata->clust_size) {
++			if (buffer_blk_cnt == mydata->clust_size) {
+ 				int nxtsect = 0;
+ 				int nxt_clust = 0;
+ 
+@@ -1086,11 +1119,11 @@ int do_fat_read_at(const char *filename, loff_t pos, void *buffer,
+ 				root_cluster = nxt_clust;
+ 
+ 				cursect = nxtsect;
+-				j = 0;
++				buffer_blk_cnt = 0;
+ 			}
+ 		} else {
+-			if (j == PREFETCH_BLOCKS)
+-				j = 0;
++			if (buffer_blk_cnt == PREFETCH_BLOCKS)
++				buffer_blk_cnt = 0;
+ 
+ 			rootdir_end = (++cursect - mydata->rootdir_sect >=
+ 				       rootdir_size);