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Hi Guys,
after desoldering and doing it the long way i took the time to figure out how to unbrick a wm8505 apad tablet via jtag, for those who may be intereseted ….
when turning on the device it got stuck at
WonderMedia Technologies, Inc.
W-Load Version : 0.19.00.01
hmm no u-boot there… so get out your jtag cable and tools (i used openocd 0.4.0)
once its all connected openocd should display
Open On-Chip Debugger 0.4.0 (2010-02-22-19:05)
Licensed under GNU GPL v2
For bug reports, read
http://openocd.berlios.de/doc/doxygen/bugs.html
trst_and_srst separate srst_gates_jtag trst_push_pull srst
Info : clock speed 6000 kHz
Info : JTAG tap: WM.cpu tap/device found: 0x07926f0f (mfg:
ver: 0×0)
Info : Embedded ICE version 6
Info : WM.cpu: hardware has 2 breakpoint/watchpoint units
now telnet to localhost on port 4444
, and issue a soft_reset_halt, followed by a reset init
now you need to load a full 512K image of the spi
> load_image 4m.bin
524288 bytes written at address 0×00000000
downloaded 524288 bytes in 37.466145s (13.666 kb/s)
and resume the processor
> resume 0×00000000
#### SUCCESSS #####
on my serial console i get
U-Boot 1.1.4 (Apr 26 2010 – 20:48:31)
WonderMedia Technologies, Inc.
WMT U-Boot Version : 0.12.01.00.16
U-Boot code: 03F80000 -> 03FB8134 BSS: -> 04006544
RAM Configuration:
Bank #0: 00000000 128 MB
boot from spi flash.
flash:
Bank1: FF800000 — FFFFFFFF
Bank2: FF000000 — FF7FFFFF
Flash: 16 MB
In: serial
Out: serial
Err: serial
### main_loop entered: bootdelay=1
bootcmd=”nand readblob 3c00000 600000;logo show;run text1″
maddr = 0x3c00000, naddr = 0×600000
Read header
CE0: NAND FLASH ID: 0xECD59429
Err : Can not find any nand flash
Init Flash Failed rc=-1
Header is 0×00000000 0×00000000
error: magicNum = 0×0, it should be 0×80101000
show logo …..
LCD param (setting): 1,30000,8,800,480,48,40,40,3,29,13
PWM param (setting): 0,4,599,599
LCD FrameBuffer = 0x0FD00000, BMP Address = 0x03C00000
Error : Not BMP Format
Unknown command ‘textout2′ – try ‘help’
Execute register operation:
reg op: 0xD8110064 | 0×8
reg op: 0xD811008C | 0×8
reg op: 0xD81100B4 | 0×8
reg op: 0xD8110064 | 0×4
reg op: 0xD811008C | 0×4
reg op: 0xD81100B4 & 0xFFFFFFFB
reg op: 0xD8130054 | 0×1
### main_loop: bootcmd=”nand readblob fc00000 b00000;nand read 0 0 300000;bootm
0″
Hit any key to stop autoboot: 0
ATSMB Host 390KHz
SD Card is not inserted
maddr = 0xfc00000, naddr = 0xb00000
Read header
CE0: NAND FLASH ID: 0xECD59429
Err : Can not find any nand flash
Init Flash Failed rc=-1
Header is 0×00000000 0×00000000
error: magicNum = 0×0, it should be 0×80101000
CE0: NAND FLASH ID: 0xECD59429
Err : Can not find any nand flash
Init Flash Failed rc=-1
## Booting image at 00000000 …
Bad Magic Number
WMT #
NOT IDEAL, but it’s alive
at this point insert your sd card with the correct script folder and then use fatload etc/// to reflash the tablet as normal
hope this would help someone.

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  1. ano po yung jtag? Di ko po masyado magets sir.. Jhay po ito

    ReplyDelete
  2. hello, nice post ! I'm trying to do the same operation with a wm8650 based tablet, but can't find any valid CFG file and script for uploading a bin file to the booting SPI flash. Do you have some suggestion, or can you send the cfg and script files you used with OpenOCD to achieve such results ? Thank you in advence and my compliments for this great job :)

    ReplyDelete
  3. Gonna try this Sir! Hope this would solve my effin' problem with BLACK SCREEN on my APAD. Thanks.

    ReplyDelete

 
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