svn commit: r305178 - head/sys/boot/i386/libi386

[Toomas Soome]

> On 1. sept 2016, at 21:28, John Baldwin <jhb at FreeBSD.org> wrote:
> 
> On Thursday, September 01, 2016 06:35:13 AM Toomas Soome wrote:
>> Author: tsoome
>> Date: Thu Sep  1 06:35:13 2016
>> New Revision: 305178
>> URL: https://svnweb.freebsd.org/changeset/base/305178
>> 
>> Log:
>>  bd_int13probe() should check extended info if sector info is bad
>> 
>>  In some Dell systems and usb stick combinations, it is found that
>>  int13 AH=08 is reporting back bad sector information, preventing the
>>  boot.
>> 
>>  This update is allowing bd_int13probe() to use extended info call to
>>  build disk properties.
>> 
>>  It also can happen the total sectors count from extended info may be
>>  wrong, in such case, the CHS data is used to calculate total sectors.
>> 
>>  Reviewed by:	allanjude
>>  Approved by:	allanjude (mentor)
>>  Differential Revision:	https://reviews.freebsd.org/D7718
> 
> Hmm, can you see if this fixes
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=176748 ?
> 
> -- 
> John Baldwin


eh… well. as he was reporting about bad sector size - my patch does not check it.. so apparently that would be good check as well….  unfortunately I don’t have any of such broken BIOSes handy to verify what kind of breakage it is - are they just filling EDD with garbage or is there any kind of logic. 

rgds,
toomas