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Bochs video log

Posted: Wed Aug 16, 2006 7:34 pm
by Candamir
I was wondering if there was some method in Bochs which I could use to write everything that I print on the (emulated) screen to some file. I'm not talking about bochsout.txt, but something that's like a snapshot of everything ;D. Because when I have a huge amount of information that is printed out very quickly (like a lot of core dumps), I can't retrieve that information...

Candamir

Re:Bochs video log

Posted: Wed Aug 16, 2006 8:51 pm
by nick8325
I'm not sure if there's a way to do exactly what you want. But, Bochs will output any characters that you write to port 0xe9. So if you make your putchar function output to port 0xe9 as well as the screen, it should help.

Re:Bochs video log

Posted: Thu Aug 17, 2006 12:28 am
by ed_tait
The version of bochs I'm using has a 'snapshot' (the icon is a camera) option in the tool bar. this dumps all the characters on the screen to a text file. I'm using the widows 2.2.6

Re:Bochs video log

Posted: Thu Aug 17, 2006 12:34 am
by distantvoices
@ed_tait: in that case candemir 'd need to be quick enough to capture all the info scrolling over the screen.

@candemir: Try this: after printing out a dump, place a get_key or similar so that it continues upon your request. This way, debugging lots of stuff works out quite easy for you can actually see what's going on. :-) HtH

stay safe

Re:Bochs video log

Posted: Thu Aug 17, 2006 10:30 am
by Candamir
nick8325 wrote: I'm not sure if there's a way to do exactly what you want. But, Bochs will output any characters that you write to port 0xe9. So if you make your putchar function output to port 0xe9 as well as the screen, it should help.
It's exactly what I need. Thanks. But do you know what happens if I also have this outportb(0xe9,c); running on a real machine?

Candamir

Re:Bochs video log

Posted: Thu Aug 17, 2006 10:46 am
by Kemp
It'll send the character's value to port 0xe9 :P As for what's waiting at that address, I'd guess nothing in the hope that it was chosen by the BOCHS guys purely due to it not being used for anything (or anything in common use).

Re:Bochs video log

Posted: Thu Aug 17, 2006 10:52 am
by Candy
Try the port list that was added to Ralf Brown's Interrupt List a long time ago. I expect it'll just be nothing (literally).