Funny to see this come back and see my write-up linked. I did this 8 years ago and think I was the first on this particular board (although others had done similar on other boards). I still have a pile of them sitting on my desk because I accidentally kept bricking them by being ... not careful. That said, even at the time this board was already old, so I guess it's positively prehistoric at this point. I eventually stopped working on this because I thought that others were making sufficient progress. It hasn't really fully materialized yet, but between openbmc, opensil, DC-SCM and the work the oxide folks are doing, I'm still hopeful that we'll get out of server firmware hell eventually.
Out of curiosity: how "bricked" are these boards? Is there irreversible hardware damage (and, if so, how?), or has some firmware just gotten overwritten?
One of them I managed to fry the pcie root complex somehow, not sure exactly how. One I damaged the traces to the BMC SPI flash. Two others I think just have bricked firmware, but it's been years, so I don't remember for sure.
This is very interesting, but I'm a little lost. UART is serial. Are they trying to get a serial terminal set up with some chip on this motherboard? Wat does it let them do?
"X11SSH" is a Supermicro motherboard [1] with a (fairly common) Aspeed BMC implementing IPMI. (It has nothing to do with X11 or SSH - the name is an unfortunate coincidence.) The UART that is being accessed here is a debug UART for the BMC, which also runs Linux.
Funny to see this come back and see my write-up linked. I did this 8 years ago and think I was the first on this particular board (although others had done similar on other boards). I still have a pile of them sitting on my desk because I accidentally kept bricking them by being ... not careful. That said, even at the time this board was already old, so I guess it's positively prehistoric at this point. I eventually stopped working on this because I thought that others were making sufficient progress. It hasn't really fully materialized yet, but between openbmc, opensil, DC-SCM and the work the oxide folks are doing, I'm still hopeful that we'll get out of server firmware hell eventually.
Out of curiosity: how "bricked" are these boards? Is there irreversible hardware damage (and, if so, how?), or has some firmware just gotten overwritten?
One of them I managed to fry the pcie root complex somehow, not sure exactly how. One I damaged the traces to the BMC SPI flash. Two others I think just have bricked firmware, but it's been years, so I don't remember for sure.
This is very interesting, but I'm a little lost. UART is serial. Are they trying to get a serial terminal set up with some chip on this motherboard? Wat does it let them do?
"X11SSH" is a Supermicro motherboard [1] with a (fairly common) Aspeed BMC implementing IPMI. (It has nothing to do with X11 or SSH - the name is an unfortunate coincidence.) The UART that is being accessed here is a debug UART for the BMC, which also runs Linux.
[1]: https://www.supermicro.com/en/products/motherboard/x11ssh-f
Great explanation.
What is the benefit of this?
Possibility of runtime exploration of the system which may help in OpenBMC port.