N.B. this section is far from being complete and contains generally inaccurate information. It's just here for my note taking until I have worked things out properly. This has all been tested against a version 2 box, but should work with the almost identical version 3 as it just has twice the RAM and NAND space.
The idea of this page is to try and document my slow and irregular work to get Linux working on the Linksys WAG54G (version 2) without using the OpenWRT distribution.
Seems that all the instructions relating to the WAG54G are different on the internet to the version of the ADAM2 bootloader that I have (version 0.22.12). I do not get the exciting option of FTP however I do get TFTP, which is available when the bootloader kicks in (you can give yourself a larger window of opportunity if you interrupt it by pressing any key over the serial port) with:
$ tftp -v -m binary 192.168.1.1 -c put openwrt-WA21-jffs2-64k-code.bin
The above command then flashes what is '`mtd4`' in the partition table below.
Another gotcha is a broken capacitor (33uF 16V) can lead to all sorts of trouble. I had this issue with all three WAG54Gs I have bought off fleabay and found that with one of them I was able to get a temporary workaround by using a direct connection from my laptop by typing:
# ethtool -s eth0 autoneg off speed 10 duplex half
The onboard 4MB (64kB erase size) NAND is partition as follows.
| partition | start | end | size | name |
|---|---|---|---|---|
| mtd0 | 0x900e0000 | 0x903f0000 | 3136kB | rootfs |
| mtd1 | 0x90020000 | 0x900e0000 | 768kB | kernel |
| mtd2 | 0x90000000 | 0x90020000 | 128kB | adam2 bootloader |
| mtd3 | 0x903f0000 | 0x90400000 | 64kB | adam2 cfg |
| mtd4 | 0x90020000 | 0x903f0000 | 3904kB | kernel + rootfs |
Under Linux the `ar7part.c` driver is meant to spit out a suitable partition table for both bootloaders (PSPBoot and ADAM2) that are available on the AR7 platform however it does not and should not be used; for me the 'rootfs' partition overlaps the 'linux' partition.
The best serial port mod I have seen for the Linksys routers is done by placing a standard stereo 3.5mm headphone jack onto the front leg of the box. This makes for a very tidy setup, however what to plug into the headphone jack and how do you wire it up? Well FTDI make very nice serial cables that work great under Linux, including the TTL-232R-3V3-AJ which means you do not need to mess with a MAX-232 chip or soldering.
Wiring it up could not be any easier, the pinout of the TTL-232R-3V3-AJ is available from their website and the pinout is shown below (shamelessly stolen from the old OpenWRT wiki); remember that when wiring you attach the TX pin of one end to the RX pin of the other and of course GND to GND.
|
| __
| | | <- Pin 1, GND
| --
| | | <- Pin 2, Not Connected
| --
| | | <- Pin 3, Router's Serial RX
| --
| | | <- Pin 4, Router's Serial TX
| --
| | | <- Pin 5, VCC
| --
|
|
\__led__led__led__led____________________
Front of WAG54G
Once all hooked up, you should see some action when you load minicom and configure the serial port to run at 38400 8N1 with no hardware or software flow control.
Never did get the JTAG working, but here are some useful links:
You will also probably need the ADAM2 0.22.12 bootloader blob.
$ # svn co svn://svn.openwrt.org/openwrt/trunk openwrt $ git clone git://nbd.name/openwrt.git $ gcc -o srec2bin openwrt/tools/firmware-utils/src/srec2bin.c $ gcc -o addpattern openwrt/tools/firmware-utils/src/addpattern.c
The 'cook-firmware' script is as follows:
#!/bin/sh -eu
objcopy -S -O srec --srec-forceS3 linux/vmlinuz vmlinuz.srec
./srec2bin vmlinuz.srec vmlinuz.bin
if [ $(wc -c vmlinuz.bin | cut -d' ' -f1) -gt 786432 ]; then
echo kernel too big
exit 1
fi
# we only need the following:
# MAKEDEV std
# MAKEDEV consoleonly
# MAKEDEV ptmx
# MAKEDEV ttyS0
# rm tty0 ram* loop*
cat <<'EOF' > /tmp/mkfs.devtable
# <name> <type> <mode> <uid> <gid> <major> <minor> <start> <inc> <count>
/dev/mem c 640 0 15 1 1 - - -
/dev/kmem c 640 0 15 1 2 - - -
/dev/null c 666 0 0 1 3 - - -
/dev/port c 640 0 15 1 4 - - -
/dev/zero c 666 0 0 1 5 - - -
/dev/full c 666 0 0 1 7 - - -
/dev/random c 666 0 0 1 8 - - -
/dev/urandom c 666 0 0 1 9 - - -
/dev/tty c 666 0 15 5 0 - - -
/dev/console c 600 0 5 5 1 - - -
/dev/ptmx c 666 0 5 5 2 - - -
/dev/pts d 750 0 0 - - - - -
/dev/ttyS0 c 660 0 20 4 64 - - -
/bin/busybox f 4755 0 0 - - - - -
EOF
/usr/sbin/mkfs.jffs2 -D /tmp/mkfs.devtable -X zlib -x lzo -x rtime -e 65536 -n -p -t -l - d buildroot/output/target/ --squash -o fs.img
if [ $(wc -c fs.img | cut -d' ' -f1) -gt 3211264 ]; then
echo filesystem too big
exit 1
fi
rm /tmp/mkfs.devtable
( dd if=/dev/zero bs=16 count=1; dd if=vmlinuz.bin bs=786432 conv=sync; cat fs.img ) | ./ addpattern -o firmware-code.bin -p WA21
tftp -v -m binary 192.168.1.1 -c put firmware-code.bin
exit 0
Time to build yourself a toolchain and the root filesystem:
$ git clone git://git.buildroot.net/buildroot $ cd buildroot $ git checkout -b wag54g origin/next $ # cp ../buildroot.conf/config .config $ make menuconfig $ # UCLIBC_CONFIG_FILE=../buildroot.conf/uclibc.config make uclibc-menuconfig $ # BUSYBOX_CONFIG_FILE=../buildroot.conf/busybox.config make busybox-menuconfig $ make $ rm output/target/sbin/ip $ ln -s ../bin/busybox output/target/sbin/ip
Prepare the kernel source:
$ git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
$ cd linux
$ # git remote add mips git://git.linux-mips.org/pub/scm/linux-queue.git
$ # git fetch -n mips
$ git checkout -b ar7 v3.2
$ export OPENWRT=$(git --git-dir=../openwrt/.git log -n1 | sed -n '/git-svn-id:/ s/^.*trunk@\([0-9]\+\) .*$/\1/ p')
$ # patch -p1 drivers/tty/serial/8250.c ../openwrt/target/linux/ar7/patches-2.6.37/500-serial_kludge.patch
$ # git commit -s -m "Apply [[OpenWRT]]@$OPENWRT Serial Kludge patches" drivers/tty/serial/8250.c
$ # do *not* apply the cpmac patches
$ # find ../openwrt/target/linux/ar7/patches-2.6.37 -type f -name '9*-cpmac*.patch' | xargs cat | patch -p1
$ # git commit -s -m "Apply [[OpenWRT]]@$OPENWRT CPMAC patches" -a
$ # tar c -C ../openwrt/target/linux/generic/files drivers/net/phy/{adm6996.{c,h},swconfig.c} include/linux/switch.h Documentation/networking/adm6996.txt | tar vx | xargs git add
$ # cat ../openwrt/target/linux/generic/patches-3.0/70* ../openwrt/target/linux/generic/patches-3.0/720-phy_adm6996.patch | patch -p1
$ # git commit -s -m "Apply [[OpenWRT]]@$OPENWRT ADM6996 patches" -a
Time to cook your kernel:
$ alias mmake="ARCH=mips CROSS_COMPILE=/usr/src/wag54g/buildroot/output/host/usr/bin/mipsel-linux- make" $ # 'mmake ar7_defconfig' or 'cp ../linconf .config' $ # try to get as much as you can in the main kernel, as modules take up filesystem space $ mmake menuconfig $ mmake -j$(grep ^processor /proc/cpuinfo | wc -l) $ INSTALL_MOD_PATH=/usr/src/wag54g/buildroot/output/target mmake modules_install
Now run the 'cook-firmware' script and you should end up with a suitable image.
A list of issues and hints I have found with the kernel:
Might be interesting for you, I use the following cmdline:
CONFIG_CMDLINE="mtdparts=physmap-flash.0:3136k@896k(rootfs),768k@128k(kernel),128k@0k(adam2)ro,64k@4032k(adam2-cfg)ro,3904k@128k(kernel+rootfs) rootfstype=jffs2 root=mtd0 rw"
If you cannot deal with the OpenWRT sangam-atm setup, you can download a tarball of my git tree that I have for it:
$ wget http://stuff.digriz.org.uk/sangam-atm.tar.bz2 $ tar jxf sangam-atm.tar.bz2 $ cd sangam-atm $ mmake
If you use PPPoE, you will also need the br2684ctl tool. You will need to CVS checkout the tree at http://linux-atm.sourceforge.net/:
$ cd linux-atm $ CC=/usr/src/wag54g/buildroot/output/host/usr/bin/mipsel-linux-gcc ./configure --with-kernel-headers=/usr/src/wag54g/linux/include/ --host=mipsel-unknown-linux-uclibc $ cd ../buildroot/output/target $ cp ../../../linux-atm/src/br2684/.libs/br2684ctl usr/sbin $ cp ../../../linux-atm/src/lib/.libs/libatm.so.1.0.0 usr/lib $ /usr/src/wag54g/buildroot/output/host/usr/bin/mipsel-linux-sstrip usr/sbin/br2684ctl $ /usr/src/wag54g/buildroot/output/host/usr/bin/mipsel-linux-sstrip usr/lib/libatm.so.1.0.0 $ ln -s libatm.so.1.0.0 usr/lib/libatm.so $ ln -s libatm.so.1.0.0 usr/lib/libatm.so.1
TODO: http://www.andybotting.com/wordpress/openwrt-on-the-d-link-dsl-502t-gen-1, 'setenv modulation MMODE'
git clone git:acx100.git.sourceforge.net/gitroot/acx100/acx-mac80211''