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event:2014:hacksession

Dies ist eine alte Version des Dokuments!


Hacksessions

In short:

a project by exco&makefu for social interaction, hacking skills, doing stuff

Hacksessions #5

Any ideas? Just do it.

#2-4 minikrebs upgrading

exco, makefu, toerb, albi, alexander, namevergessen we learned/showed/helped each other

  • different techniques how to de- resolder the chips (with old ram sticks).
  • programming of the new soic-8 flash chips witha CH341A programmer (windows only, even after hack session)
  • infrared soldering/hot air reflow soldering / manual smd soldering: 32MB → 64MB Ram, 4→ 16MB flash
  • adding external SMA-connector for external antennas - simple and sweet hack
  • dd/cat new images
  • flashing openwrt
  • completely read through (not skim) wifi and forum entries, makefu completely overlooked that the bootloader contains two parts:
    • Boot-loader (mtd0)
      • 64k u-boot (pepe2k)
        • cd u-boot_mod; make tplink_mr3020
      • 64k data (copy from old image)
        • dd if=old_image.bin of=data.bin bs=1 skip=65536 count=65536
    • openwrt-image (mtd1-mtd3)
      • we built one which provides maximum size (16mb) for building and with write-protection removed from mtd0 and mtd4
    • ART (mtd4)
      • 64k wifi config data (copy from old image)
      • dd if=old_image.bin of=art.bin bs=1 skip=$1)
  • the u-boot_mod by pepe2k (https://github.com/pepe2k/u-boot_mod) is absolutely great as it provides an extremely simple way to upgrade the router via http-failsafe. Hold button for 3 seconds to get http-server at 192.168.1.1

Code here - git repo:

Hardware Platform is in most cases the TP-Link WR703N / WR702N / MR3020

Upgrades (all above mentioned devices):

## Flasher WCH CH341A

# uboot

  • you need to upgrade uboot to be able to use new 16MB flash chip and find ART partition and more … makefu go

https://github.com/pepe2k/u-boot_mod

#crosscompiling

## gui didn't seem to be working for me: as a user

  • ./installer -console
  • click through…
  • location: $HOME/sc_mips

## add to path echo „export $PATH=$PATH:$home/sc_mips/bin“ » ~/.zshrc

## goto checked out project cd u-boot_mod make tplink_wr703n make tplink_mr3020

Buy WR703N at:

WR702N

MR3020

pics

… got lucky … all pulled pads were not connected ;-)

  • img_20140124_222731.jpg
  • img_20140124_205544.jpg

keeping everything in order

  • img_20140320_205504.jpg

Lessons Learned

  • don't pull traces off the pcb / roy bear (killed his wr702n)
  • upgrading ram chips sucks donkey balls / one-two are fine … more … no fun
  • 16MB flash requires a different u-boot / makefu
  • computers just suck / makefu
  • sometimes an easy task just isn't that easy - even if _the internet_ tells you otherwise /all
  • a 150mil sop8 programming adapter won't fit a 200mil chip
  • blinking led's are awesome / albi
  • barbecue takes too much time away from your hacking session / albi
  • rp SMA is not the plug you want

#1: Soundflower

1)
$old_image_size - 65536
event/2014/hacksession.1395362485.txt.gz · Zuletzt geändert: 2014-03-21 01:41 von 78.42.84.17