Contents
1. Status of the AR7 port of OpenWrt
1.1. What is this AR7 stuff?
AR7 is a router platform by Texas Instruments, which is used for routers and ADSL gateways.
See the TableOfHardware for supported AR7 routers.
See OpenWrtDocs/InstallingAR7 if you are brave enough to test it.
1.2. Finished tasks
Our Kernel support for AR7 is in SVN trunk. Here's what we have integrated so far (for Linux kernel 2.4, no longer supported):
- A kernel that boots up to the part where it tries to mount the root filesystem
- A simple mtd flash map driver that uses the boot loader's partition map
Running a shell with a modified OpenWrt rootfs works!
- We have working (and free) drivers for Ethernet and ADSL in SVN!
- The flash map driver is working, but needs more testing
- We have the source for the TI WLAN driver
- With the new stuff in SVN, it now sets up the networking stuff, so you can log in via telnet on 192.168.1.1 (or whatever you configured in menuconfig). That can be changed in /etc/config/network
- The VLYNQ bus works
- The LZMA loader works and is integrated
- Support for WAG354G is integrated, still needs testing...
- ADSL works! New init scripts for PPPoE are integrated.
- Scripts for flashing DSL-G664T and G604T
The latest contributions add experimental AR7 support for Linux 2.6:
- Automatic detection of RAM size.
- Automatic detection of PHY (Ethernet Physical Layer).
- ADSL works, status of ADSL+ support is not clear.
- Ethernet works (but still needs some fixes - maybe fixed in kernel 2.6.22.4).
- WLAN works with free ACX111 driver (no WPA/WPA2).
- There is also an acx-mac80211 driver, but as yet (r9450) this driver is incapable of AP mode.
The latest Linux kernel 2.6.22.4 is now supported for AR7.
1.3. Bugs / Ugly-Hacks
I would like to keep a list of the bugs and ugly-hacks used to make the ar7 work, so that they can be removed.
arch/mips/ar7/reset.c: the functions are empty. Please implement this without using the tnetd code, if possible. (reboot works now, shutdown/halt does not yet.) -- nbd: for halt, you probably only need __cli() + while(1); z3ro: there are some tnetd functions for halt... hopefully we can use the code from these without needing all of the tnetd code. enrik: I have some improvements for the code including a jump back to ADAM2 on halt. Will send patch soon.
arch/mips/kernel/setup.c: We have some #ifdef CONFIG_AR7 ... #else ... #endif because of the memory offset, we should use the generics here and modify the functions in mm/bootmem.c (this will kill some #ifdef CONFIG_AR7's in other files, too.)
arch/mips/mm/init.c: These #ifdef CONFIG_AR7's are related to not having the proper code in mm/bootmem.c, see previous list item. enrik: I have generalized the arch/mips/kernel and .../setup code to always use the more general bootmem-functions and done some initialization cleanup, too. Will send patch soon.
- LED/pin driver is in a mess. Proc entry is named /proc/led/led instead of /proc/led_mod/led as was in original 2.4.17_mvl21-malta-mips_fp_le kernel, writing to in does nonthing, reading leads to "Unable to handle kernel paging request" exception. Entry /proc/led_mod/ar7reset, that was present in original kernel and was reading state of "reset" pin in back of device, is completely missing.
- Please document any more bugs/ugly-hacks found.
1.4. TODO
- Complete the init scripts, remove nvram dependencies where they are still present...
- Test WAG354G support
- Fix the wireless driver (fixed with Linux 2.6)
Fix VLYNQ interrupt and reset handling (needed for the wireless driver). See http://forum.openwrt.org/viewtopic.php?id=2654 for possible patches. (fixed with Linux 2.6)
Generalize scripts/dlink.pl so that it works with other ADAM2 versions as well (like FritzBox)
- Get voicedump (VP101X120C) supported (Voice over ip chip on Siemens and SMC based hardware)
- Get Marvel 88E6060 switch supported (on sx541,smc and castlenet)
- Add USB support
- Support AR7 devices running in big endian mode (Zyxel!)
See also https://dev.openwrt.org/report/ (all tickets with AR7 in the summary).
1.5. Firmware/Bootloader
There are at least 4 variants
Telogy Networks, Inc ADAM2 + Linux - most Linux based AR7 devices
TI PSP bootloader PSPBoot + Linux - WAG354G, WRTP54G, ADSL2MUE, others
Bootbase + ZyNOS - ZyXEL Prestige 660 Series, maybe other ZyXEL series
Broad Net Technology, Inc. BRN bootloader and VxWorks (realtime OS with SOHO.BIN) - most (all?) VxWorks based devices, e.g. Sinus 154 DSL Basic, Siemens SX 541, SMC SMC7908VoWBRB, SMC7904WBRB2.
Note: Even on VxWorks based routers with the BRN bootloader, it is possible to install Linux and OpenWrt! See http://forum.openwrt.org/viewtopic.php?id=2654 for more details.
There are also at least two variants of ADAM2. My version (0.22.06) allows flashing of each mtdblock by ftp, others have reported they must flash a complete image via tftp TFTP is probably specific to CyberTAN-based stuff (almost exclusively Linksys). All other vendors seem to use FTP
There are two ADAM2 environment controlling boot process:
- autoload = 0|1
- autoload_timeout = N sec.
2. Emulation
You can use the MIPS emulator QEMU to emulate an AR7 based router in software. See http://forum.openwrt.org/viewtopic.php?id=5488 for more details.
3. How to help
If you want to help and got some basic kernel hacking knowledge, you should start by familiarizing yourself with the OpenWrt build system. It now has support for building images for non-broadcom hardware. All the kernel and image stuff is in the target/ subdirectory.
AR7-specific kernel patches go into target/linux/linux-2.4/patches/ar7. The build system part that constructs the firmware images for AR7 based routers is in target/linux/image/ar7. You can also find the kernel loader there.
If you'd like to help out and maybe have a patch or two, please talk to one of the developers working on this via IRC in the OpenWrt channel. Some people working on this are: nbd, wbx, wickus, z3ro, ralf, mache, sw_ and ydef.
3.1. IRC
There is a specifically targeted #ar7 irc channel complementary to #openwrt on Freenode where those devoted to hacking ar7 based routers go to hang out.
4. Other stuff
4.1. Model-specific information
Mode-specific information can be found on that model's page. See CategoryAR7Device.
4.2. JTAG
The AR7 is based on ejtag version 2.6.
This EJTAG layout should support all AR7 based boards with a 14 pin jtag pinout. The same cable as used for the standard wrt54g (based on the xilinx III/dlc-5) as demonstrated by HairyDairyMaid can be constructed and is well documented. Debug INT pin 13 is optional and pin 14 can be left unhooked for passive cabling.
Since DMA Routines do NOT exist for this ejtag version (compared to ejtag v2.0 supported on the wrt54g) interfacing requires a rewrite utilizng prAcc routines of the v2.6 standard.
JTAG for D-Link DSL-30xT, JTAGInterface (Italian!)
As of 2008-01 there is a new, actively developed fork of openwince JTAG tools with EJTAG driver included, named "UrJTAG": http://urjtag.org - it should be working with AR7 based boards as well (try latest version from Subversion repository)
it is possible to use derivative of jtag-tools (GPL) with EJTAG driver included to work with flash on AR7 based boards http://star.oai.pp.ru/jtag/jtag-brecis-ok.zip It works with Xilinx-cable (5 resistors).
See a JTAG_Cables page for more info
commands example for Dlink DSL-500T router:
jtag> cable parallel 0x378 DLC5 jtag> detect jtag> detectflash 0x30000000 1 jtag> readmem 0x30000000 0x400000 dsl-500t-fullflash.img jtag> flashmem 0x30000000 adam2.img
