= Unbricking WM8650 based tablet =

(PRELIMINARY VERSION - TO BE ADJUSTED ;) 

Interface to adapt 3.3v signals to RS-232:

{{attachment:Max233sch.jpg}}

made as

{{attachment:skilled.jpg}}

connect here:

{{attachment:conn.jpg}}

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

launch "ckermit" 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.



[[attachment: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
 * http://www.techknow.me/forum/index.php?topic=141.0

LA FICA A RAZZI


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