Date: Wed, 20 Mar 2002 21:45:21 +0000 From: Hiten Pandya <hiten@uk.FreeBSD.org> To: jhb@FreeBSD.org Cc: hackers@FreeBSD.org Subject: Re: Debugging BTX Faults Message-ID: <20020320214521.A23027@hpdi.ath.cx>
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--UugvWAfsgieZRqgk Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 20-Mar-2002 Hiten Pandya wrote: > Hi all, > > How does one debug faults in the BTX Loader? I am currently trying > to work on PR i386/21559, and after reading jhb's document on the > loading process, I was curious to know.. > Well, you need to be fairly familiar with how IA32 works. The int=3D > number is the fault that was triggered. Then, use a program to convert= =20 > the hex dump at cs:eip to binary Which tool can be used for this task? Any available in the ports? > and run that through ndisasm or ndisasm -U depending on if the code=20 > segment in cs is USE32 or not) to see what instruction it died on.=20 > You then look up that instruction in teh reference manual and see how=20 > the given fault can be triggered. Some faults are rather obvious just=20 > from the fault number and don't require you to look up the instruction. = =20 > Sometimes it's not the actual instruction that's the problem, but instead= =20 > you managed to hose the stack or some such in which case you just ahve to= =20 > look at the register and stack dumps to try and figure out what went=20 > wrong. Thanks for the kind help. :) Regards, --=20 Hiten Pandya http://jfs4bsd.sf.net - JFS for FreeBSD (JFS4BSD) http://www.FreeBSD.org - The Power to Serve Public Key: http://www.pittgoth.com/~hiten/pubkey.asc --- 4FB9 C4A9 4925 CF97 9BF3 ADDA 861D 5DBD E4E3 03C3 --- --UugvWAfsgieZRqgk Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (FreeBSD) Comment: For info see http://www.gnupg.org iD8DBQE8mQLvhh1dveTjA8MRAuZLAKCwRgXQn3IFijdpxTGTKiRad4lhgACdHMuo qBUaBTLpOHszdvIdGkM7fqE= =Yo2w -----END PGP SIGNATURE----- --UugvWAfsgieZRqgk-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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