[Mipsbook-devel] how to recover U-Boot...
graham.gower at gmail.com
Fri Jun 11 00:58:52 CEST 2010
If you have damaged the u-boot on the NAND, then you will need to
recover with a JTAG.
There are two likely connectors for this. The Libra dev board has a 14
pin (male) header which attaches directly to Ingenic's JDI. The PMP
dev board has a 46 pin (female) header which attaches to a "debug
board". The PMP debug board contains an ethernet phy, an RS232
connector and the 14 pin header to attach to the JDI.
Presumably one could use any 14 pin EJTAG device with this, but I have
It is highly likely you could use the u-boot image for one of these
dev boards in order to boot a kernel as the mipsbook is likely based
upon one (or both) of these reference designs.
On 11 June 2010 04:55, Dr. H. Nikolaus Schaller <hns at computer.org> wrote:
> Am 10.06.2010 um 20:44 schrieb Ruben Viets:
> Hi Nikolaus,
> How did you damage it ? That is not easy.
> I can't tell exactly. I did experiment with mounting the mtdblk4 and 5 and
> it did choose and find a yaffs2. Then I got some write errors as described
> in the other mail.
> After "shutdown -h now" the machine did not switch off completel so I
> pressed the power button for 5 seconds. Then, I copied a new version of my
> kernel to the SD card but it did not boot any more. Even the old kernel did
> boot. And, there is no apparent reaction on the U-Boot modifier keys. Not
> even after removing and reinstalling power supply and battery.
> - You could try the reset button at bottom. If you are lucky your jz4730
> was only stuck and will be able to boot again.
> A, good idea that I can try. Hm. Has no differnent effect as pressing the
> power button for 5 seconds.
> Some other info and hints:
> - Could be the LPC915F MCU is companion for boot
> ? http://projects.kwaak.net/twiki/bin/view/Epc700/HardwareLayout
> According to the data sheet this is the power controller. The only interface
> to the CPU allears to be I2C
> - Check some debug info on simular debug
> boards ftp://ftp.ingenic.cn/4hw/01_DEV_board/DB4730_Libra/DB4730_Libra-SW-EN.pdf
> Interesting information. I think the Libra is a board having NOR (ROM) and
> NAND flash, while the Mipsbook only has NAND.
> The document shows that booting from NAND is using a special first-stage
> boot loader. This should be the first 4k block in the U-Boot partition. So I
> think I may have to restore both, this NAND loader and U-Boot...
> - Flashing yourself via JTAG could be difficult, because you need to have
> some flasher tool and the original uboot.
> Check ingenic
> manual. tp://ftp.ingenic.cn/3sw/00tools/jdi/manual/JDI-Manual_EN_1.4.pdf
> Well, I have an Openmoko debug board...
> * no idea if it is compatible (starting from logic levels on JTAG port)
> * how to acces the JTAG port (cable? Pogo pins?)
> * how to access registers or pins of the CPU
> * how to manipulate these to correctly address the NAND flash
> So I think it *can* be done. But is another major project :((
> And I had not planned to learn JTAG and develop a JTAG tool...
> Any Volunteers around?
> - Ask on dutch forum for http://trendtac.hyves.nl/
> - Login to irc.freenode.net #mipsbook ask person there.
> Hopefully you'll fix it.
> If I do, we all have gained a lot...
> For the meantime I have to take another machine to convert into a brick :)
> Grt Ruben.
>> From: hns at computer.org
>> To: mipsbook-devel at linuxtogo.org
>> Date: Thu, 10 Jun 2010 19:36:21 +0200
>> Subject: [Mipsbook-devel] how to recover U-Boot...
>> Although I have not verified by connecting a serial console, it looks
>> as if I have damaged the NAND partition with U-Boot while
>> experimenting with yaffs2 drivers :(
>> Now, I can't boot the machine any more. it does no longer respond to
>> different Fn keys as described
>> at http://projects.kwaak.net/twiki/bin/view/Epc700/UbootStuff
>> Looking into the datasheets gave initial hope - but only the JZ4740
>> has an internal Boot ROM that can boot from USB (by exposing the
>> device as a client to a host). The JZ4730 can only boot from NAND or a
>> connected ROM. So if bootsel is hardwired (I assume it is) and there
>> is no external ROM (we have no info about such a thing), only JTAG
>> Any ideas? Hints? Experiences? Experienced guys to contact?
>> Mipsbook-devel mailing list
>> Mipsbook-devel at linuxtogo.org
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