EC20/EC25 Delta Firmware over the air (DFOTA) upgrades¶

An example of the DFOTA file is here: http://dfota.quectel-service.com:8088/Dfiles/EC20/EC20EQAR02A05V03-R02A09V02.zip

Start delta upgrade¶

AT+QFOTADL="http://dfota.quectel-service.com:8088/Dfiles/EC20/EC20EQAR02A05V03-R02A09V02.zip" 

It will start an internal connection manager to terminate data on the Linux module and then run wget to store the file to
"update.zip". If it worked a reboot into the recovery system will be made.

Recovery image¶

It seems that /usr/bin/recovery will be started and finds a update.zip in the right partition and will then apply
the delta updates.

Delta format¶

Delta updates are available for the bootloader (?), dsp, userdata and system. It is speculated that for the
system and userdata yaffs2 the actual filesystem will be mounted and individual files will be modified.

struct upgrade_file_begin {
   uint32_t checksum; // ???? different in all of these upgrades
   uint32_t __le len; // len.. E.g. 184014 of a 184059 file, len includes the 4 len bytes itself
   ... still a lot of 32bit length.. not really TLV
};
struct upgrade_file_trailer {
  uint32_t __le len;
  char name[len]; with trailing \0
  uint32_t null_end (four bytes 0x00)
};

Trailer...
# system.diff
50400100803801000000000000030000010000000700000073797374656d0000000000
# userdata.doff
50400100803801000000000000030000010000000900000075736572646174610000000000
# recoveryfs.diff
50400100803801000000000000030000010000000b0000007265636f7665727966730000000000
# no length in the beginning just 07... or 09 for the length of the string.. and trailing zero

Odd but also no yaffs2.. 0050.. and 00000050.. but rest splits okay so far..
# dsp2.diff
00504001008038010000000000000300000000000000000000
# boot.diff
000000504001008038010000000000000300000000000000000000
# 

Kicking the recovery binary¶

• mount /dev/mtdblock14 /mnt..
• Place update.zip to /cache/
• echo "IP_START_UPDATE" > /cache/fota/ipth_config_dfs.txt to say what to do

Was difficult to repeat, e.g. creating backup and mounting system partition failed on second/third tries

/ # ./strace -o foo.txt -f ./recovery2 
mount: mounting none on /sys/kernel/debug failed: Device or resource busy
Starting recovery on Fri Oct 14 12:39:48 2016
recovery filesystem table
=========================
  0 /tmp ramdisk (null) (null) 0
  1 / auto rootfs (null) 0
  2 /proc proc proc (null) 0
  3 /dev/pts devpts devpts (null) 0
  4 /proc/bus/usb usbfs usbfs (null) 0
  5 /dev/shm tmpfs tmpfs (null) 0
  6 /cache yaffs2 /dev/mtdblock9 (null) 0
  7 /media/card auto /dev/mmcblk0p1 (null) 0
  8 /system yaffs2 /dev/mtdblock14 (null) 0
  9 /data yaffs2 /dev/mtdblock15 (null) 0
  10 /misc mtd /dev/mtdblock10 (null) 0

rootfs on / type rootfs (rw)
/dev/root on / type yaffs2 (rw,relatime)
proc on /proc type proc (rw,relatime)
sysfs on /sys type sysfs (rw,relatime)
tmpfs on /dev type tmpfs (rw,relatime,size=64k,mode=755)
devpts on /dev/pts type devpts (rw,relatime,mode=600)
tmpfs on /dev/shm type tmpfs (rw,relatime,mode=777)
/dev/mtdblock15 on /usr type yaffs2 (rw,relatime)
/dev/mtdblock9 on /cache type yaffs2 (rw,relatime)
/dev/mtdblock13 on / type yaffs (rw,relatime)
tmpfs on /dev type tmpfs (rw,relatime,size=64k,mode=755)
/dev/mtdblock9 on /cache type yaffs2 (rw,relatime)
none on /sys type sysfs (rw,relatime)
none on /sys/kernel/debug type debugfs (rw,relatime)
proc on /proc type proc (rw,relatime)
total 3
lrwxrwxrwx    1 root     root            31 Jul 21 07:10 boot_hsic_composition -> /usr/bin/usb/compositions/empty
lrwxrwxrwx    1 root     root            30 Jul 21 07:10 boot_hsusb_composition -> /usr/bin/usb/compositions/9215
drwxr-xr-x    1 root     root          2048 Jul 21 07:10 compositions
crw--w----    1 root     root      247,   0 Jan  8  1970 /dev/ttyGS0
RB_Progress: fwrite "/dev/ttyGS1" fail
I:Checking delta update status...
handle_redbend_update: START_DELTA_UPDATE
I:Setting delta update status...
I:Delta update status is set to (IP_PREVIOUS_UPDATE_IN_PROGRESS 0)
I:Start delta update...
I:Setting recovery boot...
I:Recovery mode reached maximum retry. Clear boot message.
mtd: successfully wrote block at bebe0f4800000000
I:Set boot command "" 
I:boot.command=
I:boot.recovery=
I:Update location: /cache/update.zip
I:number of files in zip is 1 
I:verifying file at index 0
I:No radio diff images found 
I:system.diff found 
E:No modem package available.
E:No modem update needed. returning O.K
mtd: successfully wrote block at bebe23a000000000
I:Reset FOTA cookie done.
start fota update (/cache/fota/system.diff)
redbend_fs_entry: device_name: /dev/mtdblock14
redbend_fs_entry: mount_point: /tmp/system
redbend_fs_entry: update_name: /cache/fota/system.diff
redbend_fs_entry: part_name: system

RB_GetDelta: offset 0x0(0), size 0x14(20)
RB_GetDelta: offset 0x0(0), size 0x18(24)
RB_GetDelta: offset 0x4(4), size 0x3508(13576)
RB_GetDelta: offset 0x0(0), size 0x40(64)
RB_GetDelta: offset 0x350c(13580), size 0x18(24)
RB_GetDelta: offset 0x3510(13584), size 0x27(39)
RB_GetDelta: offset 0x0(0), size 0x14(20)
RB_GetDelta: offset 0x0(0), size 0x18(24)
RB_GetDelta: offset 0x350c(13580), size 0x18(24)
RB_GetDelta: offset 0x0(0), size 0x18(24)
RB_GetDelta: offset 0x0(0), size 0x18(24)
RB_GetDelta: offset 0x350c(13580), size 0x18(24)
RB_GetDelta: offset 0x3524(13604), size 0x4(4)
RB_GetDelta: offset 0x3528(13608), size 0x4(4)
RB_GetDelta: offset 0x352c(13612), size 0x7(7)
RB_GetDelta: offset 0x0(0), size 0x40(64)
RB_GetDelta: offset 0x0(0), size 0x40(64)
RB_GetDelta: offset 0x40(64), size 0x304(772)
RB_GetDelta: offset 0x344(836), size 0xd(13)
RB_GetDelta: offset 0x351(849), size 0x4a8(1192)
FS partition delta dump
RedBend: Delta Info: delta_sig - 0x6d0d05e5
RedBend: Delta Info: delta_size - 13580
RedBend: Delta Info: ver - 82000
RedBend: Delta Info: scout_ver - 80000
RedBend: Delta Info: flags - 0x80000000
RedBend: Delta Info: runtype_flags - 0x280
RedBend: Delta Info: ram_size - 0x200c8
RedBend: Delta Info: sector_size - 0x40000
RedBend: Delta Info: dic_sz - 0xdc8
RedBend: Delta Info: compress_sz - 0x4b5
RedBend: Delta Info: min_alloc_ram_use - 0x22
RedBend: Delta Info: ext_info_sz - 2
RedBend: Delta Info: num_copy - 0
RedBend: Delta Info: num_diff - 95
RedBend: Delta Info: num_insert - 3
RedBend: Delta Info: num_delete - 0
RedBend: Delta Info: num_del_dirs - 0
RedBend: Delta Info: num_dirs - 0
RedBend: Delta Info: num_del_link - 0
RedBend: Delta Info: num_link - 4
RedBend: Delta Info: num_critical_update - 95
RedBend: Delta Info: num_critical_insert - 3
RB_CreateFolder: /cache/fota/a, mode:0x1ff
open file /cache/fota/a/backup
RB_OpenFile: Path:/cache/fota/a/backup | Mode: RDONLY 
 First open() with error 2
open file /tmp/system/etc/version
RB_OpenFile: Path:/tmp/system/etc/version | Mode: RDONLY 
 First open() with error 2
open file /tmp/system/etc/version
RB_OpenFile: Path:/tmp/system/etc/version | Mode: RDONLY 
 First open() with error 2
RedBend: Error in scout, file signature mismatch in file /tmp/system/etc/version
umount: can't umount /tmp/system: No such file or directory
fota update fail (/cache/fota/system.diff)
I:fs:/cache/update.zip update err
mtd: successfully wrote block at bebe23a000000000
I:Reset FOTA cookie done.
mtd: successfully wrote block at bebe0f3800000000
I:Set boot command "" 
I:Setting delta update status...
I:Delta update status is set to (IP_PREVIOUS_UPDATE_FAILED 500)
handle_redbend_update: DELTA_UPDATE_IN_PROGRESS
I:Setting delta update status...
I:Delta update status is set to (IP_PREVIOUS_UPDATE_IN_PROGRESS 0)
I:Start delta update...
I:Setting recovery boot...
I:Error opening recovery count file. Ignore.
mtd: successfully wrote block at bebe0f4800000000
I:Set boot command "boot-recovery" 
I:boot.command=boot-recovery
I:boot.recovery=recovery

I:Update location: /cache/update.zip
E:Can't open /cache/update.zip
(No such file or directory)
mtd: successfully wrote block at bebe0f3800000000
I:Set boot command "" 
I:Setting delta update status...
I:Delta update status is set to (IP_PREVIOUS_UPDATE_FAILED 410)
mtd: successfully wrote block at bebe23a000000000
I:Reset FOTA cookie done.
RB_Progress: fwrite "/dev/ttyGS1" fail
precent:0 total:1 cur:1
Rebooting after recovery
I:Rebooting at the end of recovery module.
mtd: successfully wrote block at bebe0f8000000000
I:Set boot command ""