[LinuxBIOS] LinuxBIOS panic room

Carl-Daniel Hailfinger c-d.hailfinger.devel.2006 at gmx.net
Thu Aug 30 13:05:32 CEST 2007

On 30.08.2007 06:19, ron minnich wrote:
> On 8/29/07, Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006 at gmx.net> wrote:
>> I'd say it should accept a lar archive via serial console, perhaps using
>> ymodem, and start executing the first member of the lar.
>> A bit more detailed: If the BIOS fails to verify its checksum, it
>> outputs a message telling you about it over serial, waits for signature
>> to arrive over serial (a standard char sequence with repetitions at the
>> beginning), reads until it has one complete signature, switches serial
>> to ymodem and accepts a lar archive. The first member of the lar is then
>> executed.
>> The "wait for signature" is there to allow people to use multiple tries
>> getting serial speed right. OTOH, if the code outputs a continuous
>> stream of "TESTTEXT\n" while waiting for serial input, the other side
>> can verify serial speed settings as well.
>> What do you think?
> That's the way to go.

Can we invert the speaker line each time a byte is written out over
serial? With 115200,8,N,1 we would get an inversion frequency of
11.52kHz and a tone frequency of 5.76kHz. Comparing that tone to some
downloadable audio sample would allow people to find out if serial was
driven with the right speed.


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