nanddump: add options --bb=skipbad and padbad

In mtd-utils, the bad block options changed in favor of
--bb=[skipbad|padbad|dumpbad] and omitbad has been removed.

This patch add the --bb=skipbad and padbad methods to busybox' nanddump.
padbad is the current default behaviour.
The difference between skipbad and omitbad is this one:
On a 16K block NAND, if the 1st block of mtd0 is bad, we'll have:
nanddump  -b -l 16384 /dev/mtd0 | wc -c
0
nanddump  --bb=skipbad -l 16384 /dev/mtd0 | wc -c
16384 <- data from 1st good block

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 56 insertions, 9 deletions

diff --git a/miscutils/nandwrite.c b/miscutils/nandwrite.c
index 8c4da802f..a64b95bc5 100644
--- a/miscutils/nandwrite.c
+++ b/miscutils/nandwrite.c
@@ -36,7 +36,7 @@
 //usage:     "\n        -s ADDR Start address"
 
 //usage:#define nanddump_trivial_usage
-//usage:        "[-o] [-b] [-s ADDR] [-l LEN] [-f FILE] MTD_DEVICE"
+//usage:        "[-o] [-b|--bb=padbad|skipbad] [-s ADDR] [-l LEN] [-f FILE] MTD_DEVICE"
 //usage:#define nanddump_full_usage "\n\n"
 //usage:        "Dump MTD_DEVICE\n"
 //usage:     "\n        -o      Dump oob data"
@@ -44,6 +44,12 @@
 //usage:     "\n        -s ADDR Start address"
 //usage:     "\n        -l LEN  Length"
 //usage:     "\n        -f FILE Dump to file ('-' for stdout)"
+//usage:     "\n        --bb=METHOD:"
+//usage:     "\n                skipbad: skip bad blocks"
+//usage:     "\n                padbad: substitute bad blocks by 0xff (default)"
+//usage:     "\n        The difference between omit and skip bad block is that in the omit"
+//usage:     "\n        case, the length of the bad block is counted as part of the total"
+//usage:     "\n        dump length, and in the skip case, it's not."
 
 #include "libbb.h"
 #include <mtd/mtd-user.h>
@@ -57,6 +63,11 @@
 #define OPT_b  (1 << 2)
 #define OPT_f  (1 << 3)
 #define OPT_l  (1 << 4)
+#define OPT_bb (1 << 5) /* must be the last one in the list */
+
+#define BB_PADBAD (1 << 0)
+#define BB_SKIPBAD (1 << 1)
+#define BB_OMITBAD (1 << 2)
 
 /* helper for writing out 0xff for bad blocks pad */
 static void dump_bad(struct mtd_info_user *meminfo, unsigned len, int oob)
@@ -102,6 +113,7 @@ int nandwrite_main(int argc UNUSED_PARAM, char **argv)
         /* Buffer for OOB data */
         unsigned char *oobbuf;
         unsigned opts;
+        unsigned bb_method = BB_PADBAD;
         int fd;
         ssize_t cnt;
         unsigned mtdoffset, meminfo_writesize, blockstart, limit;
@@ -109,11 +121,14 @@ int nandwrite_main(int argc UNUSED_PARAM, char **argv)
         struct mtd_info_user meminfo;
         struct mtd_oob_buf oob;
         unsigned char *filebuf;
-        const char *opt_s = "0", *opt_f = "-", *opt_l;
+        const char *opt_s = "0", *opt_f = "-", *opt_l, *opt_bb;
+        static const char nanddump_longopts[] ALIGN1 =
+                "bb\0" Required_argument "\xff"; /* no short equivalent */
 
         if (IS_NANDDUMP) {
                 opt_complementary = "=1";
-                opts = getopt32(argv, "os:bf:l:", &opt_s, &opt_f, &opt_l);
+                applet_long_options = nanddump_longopts;
+                opts = getopt32(argv, "os:bf:l:", &opt_s, &opt_f, &opt_l, &opt_bb);
         } else { /* nandwrite */
                 opt_complementary = "-1:?2";
                 opts = getopt32(argv, "ps:", &opt_s);
@@ -138,6 +153,20 @@ int nandwrite_main(int argc UNUSED_PARAM, char **argv)
                 if (length < meminfo.size - mtdoffset)
                         end_addr = mtdoffset + length;
         }
+        if (IS_NANDDUMP) {
+               if ((opts & OPT_b) && (opts & OPT_bb))
+                       bb_show_usage();
+               if (opts & OPT_b)
+                       bb_method = BB_OMITBAD;
+               if (opts & OPT_bb) {
+                       if (!strcmp("skipbad", opt_bb))
+                               bb_method = BB_SKIPBAD;
+                       else if (!strcmp("padbad", opt_bb))
+                               bb_method = BB_PADBAD;
+                       else
+                               bb_show_usage();
+               }
+        }
 
         /* Pull it into a CPU register (hopefully) - smaller code that way */
         meminfo_writesize = meminfo.writesize;
@@ -162,9 +191,16 @@ int nandwrite_main(int argc UNUSED_PARAM, char **argv)
                 tmp = next_good_eraseblock(fd, &meminfo, blockstart);
                 if (tmp != blockstart) {
                         /* bad block(s), advance mtdoffset */
-                        if (IS_NANDDUMP && !(opts & OPT_b)) {
-                                int bad_len = MIN(tmp, end_addr) - mtdoffset;
-                                dump_bad(&meminfo, bad_len, opts & OPT_o);
+                        if (IS_NANDDUMP) {
+                                if (bb_method == BB_PADBAD) {
+                                        int bad_len = MIN(tmp, end_addr) - mtdoffset;
+                                        dump_bad(&meminfo, bad_len, opts & OPT_o);
+                                }
+                                /* with option skipbad, increase the total length */
+                                if (bb_method == BB_SKIPBAD) {
+                                        end_addr += (tmp - blockstart);
+                                }
+                                /* omitbad: do nothing */
                         }
                         mtdoffset = tmp;
                 }
@@ -182,9 +218,20 @@ int nandwrite_main(int argc UNUSED_PARAM, char **argv)
                         mtdoffset = next_good_eraseblock(fd, &meminfo, blockstart);
                         if (IS_NANDWRITE)
                                 printf("Writing at 0x%08x\n", mtdoffset);
-                        else if (mtdoffset > blockstart && !(opts & OPT_b)) {
-                                int bad_len = MIN(mtdoffset, limit) - blockstart;
-                                dump_bad(&meminfo, bad_len, opts & OPT_o);
+                        else if (mtdoffset > blockstart) {
+                                if (bb_method == BB_PADBAD) {
+                                        /* dump FF padded bad block */
+                                        int bad_len = MIN(mtdoffset, limit) - blockstart;
+                                        dump_bad(&meminfo, bad_len, opts & OPT_o);
+                                } else if (bb_method == BB_SKIPBAD) {
+                                        /* for skipbad, increase the length */
+                                        if ((end_addr + mtdoffset - blockstart) > end_addr)
+                                                end_addr += (mtdoffset - blockstart);
+                                        else
+                                                end_addr = ~0;
+                                        limit = MIN(meminfo.size, end_addr);
+                                }
+                                /* omitbad: do nothing */
                         }
                         if (mtdoffset >= limit)
                                 break;