Date: Mon, 13 Feb 2017 16:37:47 -0500 From: Eric McCorkle <eric@metricspace.net> To: cem@freebsd.org, Dimitry Andric <dim@freebsd.org> Cc: "freebsd-hackers@freebsd.org" <freebsd-hackers@freebsd.org> Subject: Re: GELI BIOS weirdness Message-ID: <9127dfc3-3c33-68c7-53a7-31753ac7e1d3@metricspace.net> In-Reply-To: <CAG6CVpWiLm0%2BzP_LBFFn9izE7gdnh=icbqpKqjNS5v2_68TMrA@mail.gmail.com> References: <6874308d-8892-2f03-d125-418949fd472c@metricspace.net> <F1DCB7BA-0E21-44A6-B80A-0E0429B235FE@FreeBSD.org> <d4d9f6b2-4aaf-1c61-f7d5-f8be908bcc73@metricspace.net> <919F6E39-476C-44B5-93EA-447D855921DE@FreeBSD.org> <CAG6CVpWiLm0%2BzP_LBFFn9izE7gdnh=icbqpKqjNS5v2_68TMrA@mail.gmail.com>
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This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --2sLGNof96H6lqXf8oL1EdggCgJ5ipDx0L Content-Type: multipart/mixed; boundary="lGo4r0nAdRGBWbhiPIVi9LqAiP2rsGBev"; protected-headers="v1" From: Eric McCorkle <eric@metricspace.net> To: cem@freebsd.org, Dimitry Andric <dim@freebsd.org> Cc: "freebsd-hackers@freebsd.org" <freebsd-hackers@freebsd.org> Message-ID: <9127dfc3-3c33-68c7-53a7-31753ac7e1d3@metricspace.net> Subject: Re: GELI BIOS weirdness References: <6874308d-8892-2f03-d125-418949fd472c@metricspace.net> <F1DCB7BA-0E21-44A6-B80A-0E0429B235FE@FreeBSD.org> <d4d9f6b2-4aaf-1c61-f7d5-f8be908bcc73@metricspace.net> <919F6E39-476C-44B5-93EA-447D855921DE@FreeBSD.org> <CAG6CVpWiLm0+zP_LBFFn9izE7gdnh=icbqpKqjNS5v2_68TMrA@mail.gmail.com> In-Reply-To: <CAG6CVpWiLm0+zP_LBFFn9izE7gdnh=icbqpKqjNS5v2_68TMrA@mail.gmail.com> --lGo4r0nAdRGBWbhiPIVi9LqAiP2rsGBev Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 02/13/2017 16:32, Conrad Meyer wrote: > "objdump -D -b binary -Mx86-64 -mi386 foo.bin" should work fine (no > symbols, though...). This is a raw binary, which is necessary for BIOS booting. boot0 is way too small to load an ELF. >=20 > On Mon, Feb 13, 2017 at 1:16 PM, Dimitry Andric <dim@freebsd.org> wrote= : >> On 13 Feb 2017, at 21:58, Eric McCorkle <eric@metricspace.net> wrote: >>> >>> On 02/13/2017 15:36, Dimitry Andric wrote: >>> >>>> This disassembles to: >>>> >>>> 0: 66 0f 38 f6 f0 adcx %eax,%esi >>>> 5: 31 c6 xor %eax,%esi >>>> 7: 8b 4d 14 mov 0x14(%ebp),%ecx >>>> a: 89 cf mov %ecx,%edi >>>> c: c1 ff 1f sar $0x1f,%edi >>>> f: 8b .byte 0x8b >>> >>> Note that this was truncated, so the sar and .byte are probably a >>> truncated instruction. >>> >>> Also, when I had printfs in place, I could see the call instructions.= >>> >>>> My first guess would be that the code simply jumped into garbage. B= ut >>>> can you post the complete .o file somewhere for inspection? >>> >>> Attached. >>> <gptboot> >> >> Can you please post the file before it's been stripped and objcopied >> from ELF to binary format? That makes it a lot easier to disassemble >> and analyze... :) >> >> -Dimitry >> --lGo4r0nAdRGBWbhiPIVi9LqAiP2rsGBev-- --2sLGNof96H6lqXf8oL1EdggCgJ5ipDx0L Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEARYIAB0WIQRELMWN3SgpoYkrmidWwohAqoAEjQUCWKInLAAKCRBWwohAqoAE jSjpAP9TctLmgMt//n1u+EDyekEWMdgoFGUX7TYnc/A4KSA1BwEAl5cvQgDiS+F1 bYCn59120efsjzEhZUrwRykYlPbGGAE= =+yzR -----END PGP SIGNATURE----- --2sLGNof96H6lqXf8oL1EdggCgJ5ipDx0L--
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