17:28 <Voidb3rg> I have a an arcade machine running an a40i (R40), I'm trying to dump the 256mb NAND (TC58NVG1S3HTA00). I think I'm close... but I'm stuck. The board is defeatured with no MMC/SD/SPI/Wifi/BT. UART is disabled by default and pin glitching gets me no output either. I did manage to get FEL mode working though but no hardware is detected.

17:29 <Voidb3rg> UART is working over FEL with mainline uboot from a BPI M2 Ultra defconfig, but it won't pickup the NAND no matter what settings I use. I've spent days trying to boot from RAM using various linux distros (including BSP) with zImages/uImages/Busybox/uEnv... but I get a kernal panic, can't find rootfs, unable to init, or other issues depending on the distro I compile with.

17:29 <Voidb3rg> There are some other intresting jumpers on the board, I put headers on them but I can't figure out what they do exactly ( SM0, RES, RESET ). There is a USB1 that I soldered a header onto, and mainline over FEL detects the controller, but always shows 0 mass storage devices found. Multimeter shows the VCC is 0v at all times for the USB so maybe they cut the trace.

17:29 <Voidb3rg> Any tips or ideas from anyone would be appreciated. I've hit a mental roadblock at this point. Here is a screenshot of the PCB with my notes - https://i.imgur.com/Y7dpwLH.jpeg

17:39 <Voidb3rg> I have a buspirate but I can't find any other protocols besides UART. All of the SOP8 chips are either audio or voltage regulators.

17:42 <machinehum> No JTAG?

17:43 <Voidb3rg> I can't seem to find any jtag sadly, but I could be wrong. The board is very defeatured

17:44 <machinehum> This seems hard

17:45 <machinehum> UART doesn't work at all?

17:45 <machinehum> I guess you said that

17:45 <Voidb3rg> It works in FEL mode if I do a sunxi-fel uboot

17:45 <machinehum> hmm

17:49 <DuClare> Not exactly my area of expertise, but if you got a kernel booting as far as looking for rootfs.. that's a strong contender for exploring from the linux side, just boot an initramfs instead of trying to mount a rootfs

17:50 <Voidb3rg> Output from my mainline boot over FEL https://pastebin.com/xGU7vJQS. I was thinking of doing a USB Boot but it never will find my "Storage Device". Multimeter shows no VCC. Externally powered hub won't work either.

17:52 <Voidb3rg> I tried to make a initramfs but I always get "Unable to init" or "unable to find rootfs". Its new to me so I tried creating my own a few different ways and tried other peoples as well. I can't ever seem to reach a console but I agree it's probably the only way.

17:54 <Voidb3rg> I tried BSP linux with a busybox rootfs. Marked the various options to include the rootfs in the zImage. I get the kernel to boot but it never finds the filesystem. Other hacks like this always include a script.bin file but I don't have one since no dump has been made for this board yet.

18:25 <jernej> Voidb3rg: NAND is not really supported on mainline and even if it would be, wear leveling algorithm would be different, so it wouldn't help you much anyway

18:27 <Voidb3rg> Is it possible to boot BSP uboot over FEL? I couldn't figure out a way to do it without having a dump of the firmware first

18:27 <jernej> I'm not sure

18:28 <jernej> probably not without changes

18:28 <jernej> apritzel might know

18:39 <jernej> Voidb3rg: I suspect AXP221S (PMIC) is not configured correctly (or at all), so you don't get power on USB VBUS

18:56 <Voidb3rg> Should I just keep messing with values in the menuconf until I can get it powered? I'm not sure if there is a method to test it inside of uboot. I enabled PMIC control but it shows on devices detected

23:49 <apritzel> Voidb3rg: jernej: you can upload and execute the boot0 part over FEL, but this will then hang (when it tries to load more)

23:50 <apritzel> AFAIK the BSP only supports one boot source for a certain firmware image (in contrast to mainline)

23:50 <apritzel> so if you extract something meant for NAND booting, you can't boot that image via FEL or MMC

23:56 <apritzel> as jernej already said, NAND is a major roadblock, just alone for the read disturbance

23:57 <apritzel> so unless you are willing to invest a lot of time in reading (hard to find) documentation and do some experimentation, I would leave the NAND alone

23:58 <apritzel> Voidb3rg: you can choose any 5V source for the USB VCC, doesn't need to come from some of the USB pins

23:59 <apritzel> so my advice would be to boot from FEL into mainline U-Boot, then use USB for loading the kernel and also have the rootfs on USB