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bridge: debug: Always try to exit debug first#60

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Manawyrm wants to merge 1 commit intoamboar:mainfrom
Manawyrm:debug-uart-reliability
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bridge: debug: Always try to exit debug first#60
Manawyrm wants to merge 1 commit intoamboar:mainfrom
Manawyrm:debug-uart-reliability

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@Manawyrm
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@Manawyrm Manawyrm commented Oct 14, 2024

The Debug UART inside the BMC can be brought into a stuck state by sending a lot of requests quickly or after sending a broken command.
Sending 2 exit commands at 115200 baud before trying to enter debug mode again seems to mitigate this issue.

Sidenote: I wonder how that Debug UART is actually realized inside the ASPEED. I'm almost guessing it's a little 8051 core or something similar, which might crash here. I would expect to see a little bit different behaviour from a hardware state machine.

The Debug UART inside the BMC can be brought into a
stuck state by sending a lot of requests quickly or after
sending a broken command.
Sending 2 exit commands at 115200 baud before trying to
enter debug mode again seems to mitigate this issue.

Signed-off-by: Sarah Mädel <sarah.maedel@hetzner-cloud.de>

// Escape character should cancel previous commands
// q will exit debug mode
rc = prompt_write(&ctx->prompt, "\x1Bq\r\n\x1Bq\r\n", strlen("\x1Bq\r\n\x1Bq\r\n"));
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Hmm, I was trying to avoid injecting things into the BMC console if I could help it. Maybe we could add this behind a --recover or --force-quit option so we can at least control when it is run?

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Hm, yup... But now we have that problem with the command line argument parsing again 😄
Would you implement this as a flag in the main culvert.c getopt()?

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Yes, that's a fair criticism :D Maybe let's leave this to lie for a bit, I'm thinking about what we can do to improve the command line parsing experience.

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Does anyone object if I cherry-pick this patchset to #73 to improve the argument parsing with my ongoing changes? ^^

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Especially if you give it a new CLI flag, absolutely, please! 😃

@sinuscosinustan
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Commit has been cherry-picked and merged with #73

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