DHT-Walnut

DHT-Walnut is a shortened name for the Digital Home Technologies PCB 01070201 Rev. 1.1.

currently available HERE Oops, sold out 2/6/2006

The board consists of:
 * PowerPC 405GP] running at 266mhz
 * PC133 SDRAM slot, currently, only supports single sidded DIMMs
 * On-chip 405GP ethernet, board doesn't have an ethernet MAC address
 * DCE serial port, speeds up to 230k, only tested to 115200
 * two pci slots, keyed for 5V only cards
 * Promise Technologies PDC20265 IDE
 * 512k of boot flash AMD 29LV040B [Media:amd29lv040b.pdf datasheet]
 * 12v dc powered
 * PPC40XX JTAG on J10
 * 6.00" x 7.5" board size

The system's most common configuration seems to be:
 * System PCB
 * 32M PC133 SDRAM DIMM
 * Unknown PCI IEEE-1394 card supported by OHCI driver
 * PPCBoot v.1.1.2 in flash

Hardware that is known to work (and not to work) with this board can be found [wiki:DHT-Walnut-Known-Working-Hardware here]

GPSFan (Freenode IRC on #edev) was helpful in providing an image of the board:



Some info in the pdf HERE

Experimental hack to set a hardware breakpoint inside OCD Commander [Media:hardbreak.tgz hardbreak.tgz]


 * OCD Commander macro file to dump the CPU configuration (all but PCI) [Media:dump_config.mac dump_config.mac]
 * OCD Commander macro file to configure the system for recovery [Media:recovery_config.mac recovery_config.mac]
 * CPU configuration of the system after a warm reset [Media:warm_reset.config warm_reset.config]
 * CPU configuration of the system once ppcboot v1.1.2 is up and running [Media:ppcboot.config ppcboot.config]
 * CPU configuration of the system once ppcboot v1.1.6 is up and running [Media:ppcboot_116.config ppcboot_116.config]
 * Example OCD logfile of the using the recovery macro to load ppcboot [Media:ocd_recovery_log.txt ocd_recovery_log.txt]
 * Example console log from ppcboot v.1.1.6 running from ram after recovery macro [Media:ocd_recovery_console_log.txt ocd_recovery_console_log.txt]

Bootloaders

 * ppcboot

Here is the latest ppcboot 1.1.6 patch, as is, it will build for flashing at 0xfff80000 as a replacement for the pcboot-1.1.2 that comes with the board.

[Media:patch-ppcboot-1.1.6-km2 patch-ppcboot-1.1.6-km2]

Original sources for ppcboot:

Here is a binary for those without a toolchain.

[Media:ppcboot1.1.6.1.bin ppcboot1.1.6.1.bin] crc = 083fb0a3

To use this (at your own risk) see the detailed update procedure description: [wiki:DHT-WalnutInstallingTheUpdatedBootloader Installing the Updated Bootloader]


 * U-Boot

U-Boot is a significantly updated replacement for ppcboot. See: [wiki:DHT-Walnut-U-Boot U-Boot for the DHT-Walnut].

Just in case you make a brick, there is hope: [wiki:DHT-WalnutJtagBootloaderInstallation JTAG Bootloader Installation]

Linux Kernels

 * Version 2.4

(Mostly) working kernel binary and config from jbevren with matrox fbcon and usb input support.

Current issues:
 * USB keyboard input doesnt seem to work, but events reach /dev/input/event0
 * [[Media:uImage]]
 * [[Media:config]]


 * Version 2.6

See: [wiki:DHT-Walnut2.6LinuxKernel 2.6 Linux kernel for the DHT-Walnut].

Userland

 * [wiki:DHT-Walnut-DebianInstall Debian GNU/Linux netboot installer] -- Install Debian from the internet to a hard disk.

How-To's

 * How To [wiki:DHT-WalnutInstallingTheUpdatedBootloader replace the bootloader with ppcboot 1.1.6]
 * How To [wiki:DHT-Walnut-U-Boot replace the bootloader with U-boot 1.1.4]
 * How To [wiki:DHT-WalnutJtagBootloaderInstallation recover from "Brickage"]
 * How To [wiki:DHT-WalnutAddJ10 add the JTAG connector at J10]
 * How To [wiki:DHT-WalnutBootViaTftp boot via tftp]
 * How To [wiki:DHT-WalnutBootingFromHdd boot from Hard Disk]
 * How To [wiki:DHT-WalnutUsefullProjects do something useful with your board]
 * How To [wiki:DHT-WalnutGPIO control the Green Media LED and J5]
 * More to come...