OpenBIOS

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4297 discussions

[Fwd: Re: [OpenBIOS] Why protected mode?]
by Andrew Kohlsmith 15 Jul '99

15 Jul '99

for some reason this message didn't make it ot the list... Andrew -------- Original Message -------- Subject: Re: [OpenBIOS] Why protected mode? Date: Thu, 15 Jul 1999 08:20:22 -0400 From: Andrew Kohlsmith <akohlsmith(a)benshaw.com> Organization: Benshaw, Inc. To: openbios(a)elvis.informatik.uni-freiburg.de References: <3.0.32.19990707182234.01c84ec0(a)pop.netschools.net> > >simulator, does it not? My recollection is that the only way out of > >protected mode (back in 286 days) was through a keyboard reset sequence. > > That was only on the '286, which required a processor reset to get back > into real mode and was assisted by the keyboard controller, one of the > Great PC Hacks. It is not as traumatic with '386 and beyond. Actually that was the kludge to fix it. The *really* savvy way to do it was a triple fault. Something along the lines (going from memory here) like trashing the stack and executing an illegal instruction. The processor would take exception to the illegal instruction (fault 1), go to push CS,IP,F to the stack, which wasn't there (fault 2), cause exception to that and go to push them again (fault 3) so it would reset. Thousands of times faster than playing with the keyboard controller to hit reset. That's all from memory so it may be a little incorrect, but the theory is sound. It may have been only a double fault, but either way that method was MUCH faster than resetting through the keyboard controller. Andrew - To Unsubscribe: send mail to majordomo(a)freiburg.linux.de with "unsubscribe openbios" in the body of the message

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mailing list errors
by Stefan Reinauer 14 Jul '99

14 Jul '99

Hi,.. I am sorry, but the mailing list seems to have some weird problems since our university just thought off some new games to make mail undeliverable. You might get one or more mails "Relaying denied." when sending to the mailing list :-( I hope it is fixed withing the next two days.. Best regards, Stefan -- Can you afford *not* to use linux? - To Unsubscribe: send mail to majordomo(a)freiburg.linux.de with "unsubscribe openbios" in the body of the message

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Re: [OpenBIOS] Why protected mode?
by Timothy J. Massey 08 Jul '99

08 Jul '99

On Thu, 8 Jul 1999 10:39:53 -0500 (CDT), Brian Hurt wrote: >) I don't know of any other free usable 16-bit DOS >compilers out there (I'd rather not use an old, properietary, unsupported >compiler like Borland C for DOS). There are very few. From my longtime experience with the FreeDOS project, we have found that the only other decent alternative is Pacific C. I don't have a link handy, but it's not quite ANSI compatible, and it has some real limitations. Tim Massey - To Unsubscribe: send mail to majordomo(a)freiburg.linux.de with "unsubscribe openbios" in the body of the message

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Why protected mode?
by Brian Hurt 08 Jul '99

08 Jul '99

Sorry about the newbie questions- I still can't get at the FAQ. Pointers to where I can get this document gladly accepted. Or a pointer to the archive of this mailing list. Or the CVS repository for the code. Why is the bios going into protected mode? This would seem to make life difficult to load an OS. Is there a game plan for dealing with this that I'm not seeing? The problem is that the linux load sequence is 16-bit code, which loads the idt and gdt and then performs dozens of more instructions before going into protected mode. The solutions I see are: 1) Don't go into protected mode. So long as addresses stay below 1 meg, this shouldn't be a problem (PCI/AGP configuration is the only reason I know of why we may need to go above 1M). 2) Go into protected mode for initial configuration, then exit it to load the boot code (note that the BIOS service routines would have to run in real mode in this case). 3) Stay in protected mode, run the OS loader in V86 mode, and "cleverly" handle the protection fauls (probably by "emulating" them- on the lidt/gidt instructions we save off their offsets, and on the lmsw instruction doing all three- lidt/gidt/lmsw). 4) Same as above, but instead of emulating the instructions, we exit from protected mode at that point, and retry the instruction (and hope that no one ever tries to use a BIOS service after executing a protected instruction). 5) Beg the OS maintainers to change their code. I dislike this option intensely- while on Linux we could probably do it (by becoming OS maintainers), I doubt Microsoft would listen. Brian - To Unsubscribe: send mail to majordomo(a)freiburg.linux.de with "unsubscribe openbios" in the body of the message

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Re: [OpenBIOS] Why protected mode?
by William Meyer 07 Jul '99

07 Jul '99

>> 2) Go into protected mode for initial configuration, then exit it to load >> the boot code (note that the BIOS service routines would have to run in >> real mode in this case). > >This is how other BIOSs today do it. That is also how you have to do if >you strive for IBM-PC BIOS compability. And this continues the necessity for either a keyboard or a keyboard simulator, does it not? My recollection is that the only way out of protected mode (back in 286 days) was through a keyboard reset sequence. William Meyer - To Unsubscribe: send mail to majordomo(a)freiburg.linux.de with "unsubscribe openbios" in the body of the message

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Other ISA port 0x80 reads (?)
by Johan Rydberg 07 Jul '99

07 Jul '99

Hi people! Does any know of any commerical sold ISA cards that reads and displays information written to ISA I/O port 0x80 ? -- Johan Rydberg Net Insight AB johan.rydberg(a)netinsight.se Ingenjörsvägen 3 http://www.netinsight.se SE-117 43 STOCKHOLM phone:+46-8-685 04 16 Sweden fax: +46-8-449 22 40 mob: +46-704-53 57 21 - To Unsubscribe: send mail to majordomo(a)freiburg.linux.de with "unsubscribe openbios" in the body of the message

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Newbie questions
by Brian Hurt 06 Jul '99

06 Jul '99

The FAQ link from the freiburg.linux.de web page seems to be broken. I apologize in advance for asking potientially frequently asked questions. Is there a CVS repository for code? It looks like I'll be adding support for the SIS530 chipset (Pentium/Socket-7), and would like to fold my code changes back into the main codeset. Thanks! - To Unsubscribe: send mail to majordomo(a)freiburg.linux.de with "unsubscribe openbios" in the body of the message

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OpenBIOS POST, flash, and IO card site.
by James Oakley 06 Jul '99

06 Jul '99

I've placed the schematics on my website at http://wiley246h122.roadrunner.nf.net:2080/openbios/ (yes, it's a static address) for the OpenBIOS development hardware. There is currently no documentation, but the circuit is, in a way, straightforward. If anybody can check it over and verify if it's correct I will be forever in your debt. For those who don't know, this is a single ISA card that allows dual-flash functionality, standard port 0x80 POST, enhanced OpenBIOS POST (to character LCD, actually human-readable!), and 5 general-purpose 8bit IO ports (for experimentation, education, and embedded designs). Feel free to contact me on any issues here. James Oakley jfunk(a)roadrunner.nf.net - To Unsubscribe: send mail to majordomo(a)freiburg.linux.de with "unsubscribe openbios" in the body of the message

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port 0x80 ?
by Johan Rydberg 05 Jul '99

05 Jul '99

Hi people! I have looked a bit at the sources and wondering what port 0x80 is? I guess that it is a port that you write information about the POST to, but what reads it? -- Johan Rydberg Net Insight AB johan.rydberg(a)netinsight.se Ingenjörsvägen 3 http://www.netinsight.se SE-117 43 STOCKHOLM phone:+46-8-685 04 16 Sweden fax: +46-8-449 22 40 mob: +46-704-53 57 21 - To Unsubscribe: send mail to majordomo(a)freiburg.linux.de with "unsubscribe openbios" in the body of the message

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Anyone here ?
by Thomas Petazzoni 05 Jul '99

05 Jul '99

Hi, I suscribed to this mailing list one week ago, but i didn't not receive any message. Is this a technical problem ? I read about OpenBios in a French magazine, called "Linux Mag". Your project seems to be very interesting, that's why i suscribed to this mailing list. Am I really suscribed ? Thanks to answer me through the mailing list and by private mail. Thank you very much Thomas, from Paris, France -- ------------------------------------------------------------------- PETAZZONI Thomas & Maxime E-mail : peta(a)club-internet.fr ICQ : 34937744 KOS-web : http://www.comports.com/kos - To Unsubscribe: send mail to majordomo(a)freiburg.linux.de with "unsubscribe openbios" in the body of the message

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