git.ipfire.org Git - thirdparty/openembedded/openembedded-core-contrib.git/blob

   1 From 35d3842cc4b930c5102eed2921e0189b7f4fd069 Mon Sep 17 00:00:00 2001
   2 From: Robert Yang <liezhi.yang@windriver.com>
   3 Date: Wed, 31 Dec 2014 16:43:37 +0800
   4 Subject: [PATCH 4/9] linux/syslinux: add ext_file_read() and ext_file_write()
   5
   6 Will use them to read and write on the extX device.
   7
   8 Upstream-Status: Submitted
   9
  10 Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
  11 Tested-by: Du Dolpher <dolpher.du@intel.com>
  12 ---
  13  linux/syslinux.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  14  1 file changed, 62 insertions(+)
  15
  16 diff --git a/linux/syslinux.c b/linux/syslinux.c
  17 index 45f080d..247c86a 100755
  18 --- a/linux/syslinux.c
  19 +++ b/linux/syslinux.c
  20 @@ -349,6 +349,68 @@ fail:
  21
  22  }
  23
  24 +/* Read from an ext2_file */
  25 +static int ext_file_read(ext2_file_t e2_file, void *buf, size_t count,
  26 +                        off_t offset, const char *msg)
  27 +{
  28 +    int                 retval;
  29 +    char                *ptr = (char *) buf;
  30 +    unsigned int        got = 0;
  31 +    size_t              done = 0;
  32 +
  33 +    /* Always lseek since e2_file is uncontrolled by this func */
  34 +    if (ext2fs_file_lseek(e2_file, offset, EXT2_SEEK_SET, NULL)) {
  35 +        fprintf(stderr, "%s: ext2fs_file_lseek() failed.\n",
  36 +            program);
  37 +        return -1;
  38 +    }
  39 +
  40 +    while (1) {
  41 +        retval = ext2fs_file_read(e2_file, ptr, count, &got);
  42 +        if (retval) {
  43 +            fprintf(stderr, "%s: error while reading %s\n",
  44 +                    program, msg);
  45 +            return -1;
  46 +        }
  47 +        count -= got;
  48 +        ptr += got;
  49 +        done += got;
  50 +        if (got == 0 || count == 0)
  51 +            break;
  52 +    }
  53 +
  54 +    return done;
  55 +}
  56 +
  57 +/* Write to an ext2_file */
  58 +static int ext_file_write(ext2_file_t e2_file, const void *buf, size_t count,
  59 +                        off_t offset)
  60 +{
  61 +    const char          *ptr = (const char *) buf;
  62 +    unsigned int        written = 0;
  63 +    size_t              done = 0;
  64 +
  65 +    /* Always lseek since e2_file is uncontrolled by this func */
  66 +    if (ext2fs_file_lseek(e2_file, offset, EXT2_SEEK_SET, NULL)) {
  67 +            fprintf(stderr, "%s: ext2fs_file_lseek() failed.\n",
  68 +                program);
  69 +            return -1;
  70 +    }
  71 +
  72 +    while (count > 0) {
  73 +        if (ext2fs_file_write(e2_file, ptr, count, &written)) {
  74 +            fprintf(stderr, "%s: failed to write syslinux adv.\n",
  75 +                    program);
  76 +            return -1;
  77 +        }
  78 +        count -= written;
  79 +        ptr += written;
  80 +        done += written;
  81 +    }
  82 +
  83 +    return done;
  84 +}
  85 +
  86  /*
  87   * Install the boot block on the specified device.
  88   * Must be run AFTER file installed.
  89 --
  90 1.9.1
  91