U-boot is configured to print its logs into com-port by default. There is a device I can't receive this information (without uart/com).

Can I configure u-boot to store its log strings into some place in memory (not to console) to sd-card?

  • I think Joe's suggestion is your best bet assuming access via debugger is available. I would just allocate a section of RAM to your logs and constantly dump from this region. Alternatively, without having to track RAM, you could do something like stlinky and skim RAM for the magic word and read from a (presumably large) buffer using an offset. Storing to disk would be non trivial and may require lots of erase/write cycles of your flash (assuming you have flash) or writing/loading a driver for your storage media.
    – sherrellbc
    Jun 22, 2016 at 19:17

1 Answer 1


U-Boot console output is probably what you are after. Writing everything out onto SD card, I am pretty sure that would be a custom implementation for you, and it would be difficult.

If you can see into memory contents (for example with JTAG debugger), there are more options, though also probably it will take some custom implementation on your part. Storing console output to a circular buffer is a fairly easy hack, do-able for someone experienced. CONFIG_PRE_CONSOLE_BUFFER is described in README but I haven't used that. Also the Coreboot platform has CONFIG_CBMEM_CONSOLE option, and some other platforms have CONFIG_CFB_CONSOLE.

It is different from what you asked for, but note CONFIG_NETCONSOLE could send console output to ethernet.

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