2013.09.23. 22:07 keltezéssel, Stefan Agner írta: > Am 2013-09-23 21:08, schrieb Gabor Juhos: >> It should be possible to fix the board via JTAG. At least it seems that the >> PCB >> has an unpopulated JTAG header. > Yes I thought about this too, but since I didn't found an openocd > configuration which should work with this SoC, I didn't even tried it. I > guess I would download U-Boot to RAM and try to reflash U-Boot from > there, right?
Yes, that would be the simplest method. > Do you have a working JTAG toolchain for this SoC? Nope, I did not have to use JTAG on any AR934x based boards yet. > Today I tested the driver. After adding the relevant Kernel > configuration (CONFIG_MTD_NAND_AR934X_HW_ECC) I could successfully read > from the device, data look good. However, when I tried to dd the whole > kernel I get some errors: > > # dd if=/dev/mtdblock7 of=/tmp/wndr4300-mtd7-kernel.img > [ 325.310000] end_request: I/O error, dev mtdblock7, sector 424 > [ 325.310000] Buffer I/O error on device mtdblock7, logical block 53 > [ 325.340000] end_request: I/O error, dev mtdblock7, sector 536 > [ 325.340000] Buffer I/O error on device mtdblock7, logical block 67 > [ 325.380000] end_request: I/O error, dev mtdblock7, sector 424 > [ 325.380000] Buffer I/O error on device mtdblock7, logical block 53 > dd: /dev/mtdblock7: Input/output error > My first guess was this is/are bad blocks. > > But U-Boot seems not to support this idea: > > ar7240> nand bad > > Device 0 bad blocks: > ar7240> > Maybe U-Boot's bad block management doesn't work with those > information... Despite what U-Boot says, those still can be bad blocks. The ar934x-ncf driver has no special bad block handling yet. > A dd command with conv=noerror leads to a image witch is 16KiB smaller > than it should be. Don't use dd on NAND flashes. Use the nanddump utility from the mtd-utils package instead. > After working only with initramfs, the default Firmware doesn't boot > anymore: > ** check rootfs image ** > Verifying Checksum ... Bad Data CRC > > This CRC checks the rootfs. Netgear put another uImage header just > before the rootfs partition (but still in the kernel partition). It > looks like the Kernel already changed something on NAND, which causes > this Bad Data CRC... > I then flashed the latest Netgear Firmware again. Guess what, I could > successfully dd the whole kernel... But dd the rootfs still has Buffer > I/O errors. > > Any idea what could go wrong here? I think it would be a good idea to > figure out whats wrong before doing further steps... Well, the hardware ECC support in ar934x-nfc driver might contain some bugs. However, I don't think that the kernel writes anything into the flash by itself. Did you write/erase the any of the partitions by any chance? -Gabor _______________________________________________ openwrt-devel mailing list [email protected] https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
