Re: [Bug-xorriso] Test Proposal for [bug #46716] Protective MBR partition is not marked as bootable

[Alexander E. Patrakov]

22.12.2015 20:05, Thomas Schmitt пишет:
> Hi,
>
> Alexander E. Patrakov wrote:
> > The following variants, obtained by changing only the MBR, also work:
> > 1. Type-0 one-sector bootable partition at the very first sector:
> > 000001d0: 0100 0000 0200 0000 0000 0100 0000 0000  ................
>
> Did you create this by partition editor or by dd ?

By xxd, vim and dd.

> While trying to mimick it, i wonder whether the "0200" should
> not be "0100". I understand that the value "02" is in byte 468 = 0x1d4:
> Sector part of C/H/S address of last absolute sector in partition 2.
> (Plus 2 bits from cylinder part which are 0.)

The CHS information is indeed bogus in my test MBRs.

> A partition from LBA 0 with 1 blocks should have C/H/S range
> 0/0/1 to 0/0/1, not 0/0/1 to 0/0/2.
>
> (I am not sure how to express the end C/H/S of an empty partition
>   at LBA 0. 0/0/0 is not really a valid C/H/S.)

I have not tested empty partitions, only partitions with size of 1 
sector or more.

> ------------------------------------------------------------------
>
> There is a new GNU xorriso development snapshot uploaded
>
>    http://www.gnu.org/software/xorriso/xorriso-1.4.3.tar.gz
>
>    MD5 5163f97f5ce9a7707ac7de6777b46283

I will look into it tomorrow.

--
Alexander E. Patrakov