Unbricking WM8650 based tablet

(PRELIMINARY VERSION - TO BE ADJUSTED

Interface to adapt 3.3v signals to RS-232:

made as

connect here:

connect serial, use ckermit (apt-get install ckermit)

launch "kermit" and write this:

set modem type none set line /dev/ttyUSB0 set speed 115200 connect

turn on the device, you will have a boot logo, press a key to block it or maybe you will have the

WMT #

prompt.

Have a copy of a working firmware for UBEROID, unpack it in a dir, and read the file wmt_scriptcmd

Now, "copy & paste" line by line from your wmt_scriptcmd to the hyperterminal.

Copy & Paste only the "setenv" lines (before "fastload", "saveenv" lines) in the "WMT #" prompt, and hit ENTER after each line.

[[ setenv kernel-NAND_ofs setenv kernel-NAND_len setenv initrd-NAND_mtd setenv initrd-NAND_ofs setenv initrd-NAND_len setenv filesystem-NAND_mtd setenv filesystem-NAND_ofs setenv filesystem-NAND_len setenv wmt.nfc.mtd.u-boot-logo setenv wmt.nfc.mtd.kernel-logo setenv wmt.display.param 2:0:16:0:0:0 setenv wmt.display.tmr 40000:0:10:46:800:20:10:23:480:10 setenv wmt.display.pwm 0:25:50:99 setenv memtotal 214M setenv wmt.display.logoaddr 500000 setenv wmt.kernel.animation.addr f600000 saveenv display init force mmcinit 0 textout -1 -1 \"WM8650 Uberoid2.2 upgrade preparing, please wait ...\" FFFF00 setenv bootargs 'mem=214M root=dev/ram0 rw initrd=0x01000000,32768K console=ttyS0,115200n8 loadtime=-4' ]]

Now, do you see those

[[ fatload mmc 0 1000000 FirmwareInstall/ramdisk.gz fatload mmc 0 0 FirmwareInstall/uzImage.bin ]]

lines in that file? we need to do those uploads by serial. As this:

[[ loadb 1000000 ]]

now press CTRL-\ C to go to Kermit console, and "send" your "ramdisk.gz" file.

if you have some error, use the SET PREFIX stuff that kermit tell you to use to solve.

now

[[ loadb 0 ]]

and send the file "uzImage.bin", in the same way as "ramdisk.gz" above.

note: after every upload you have to write "c" to kermit to reconnect to the terminal

After this, do a "bootm 0" and your system will boot.

Max233sch.jpg

Bibliografia:

http://www.techknow.me/forum/index.php?topic=261.0

http://postimg.org/image/5gyf3vn6n/

http://www.compsys1.com/workbench/On_top_of_the_Bench/Max233_Adapter/max233_adapter.html

http://www.linuxquestions.org/questions/linux-networking-3/how-do-i-send-files-in-minicom-through-kermit-633779/

http://ficara.altervista.org/?p=275

LA FICA A RAZZI