Re: Booting El Torito image from a partition table

[Andrei Borzenkov]

28.11.2015 21:34, Emilio Lazo Zaia пишет:
> 
> On 28/11/15 13:50, Andrei Borzenkov wrote:
>> 28.11.2015 21:16, Emilio Lazo Zaia пишет:
>>> On 28/11/15 13:31, Andrei Borzenkov wrote:
>>>> 28.11.2015 19:55, Emilio Lazo Zaia пишет:
>>>>> Of course isohdppx.bin code and isohybrid binary are ISOLINUX
>>>>> specific,
>>>>> so we can't combine
>>>>> them with GRUB2. The problem here seems to be that GRUB2
>>>>> boot_hybrid.img
>>>>> don't pass
>>>>> partition information to core.img because it wasn't designed to handle
>>>>> partitioned devices. Right?
>>>>>
>>>> The problem is that boot_hybrid.img does not know about partition
>>>> information that is passed to it by syslinux using method specific to
>>>> syslinux.
>>>>
>>> The only syslinux code in my example is mbr.bin that is a generic MBR
>>> binary code to boot from the
>>> first partition which has the bootable flag. In those steps we can avoid
>>> writing syslinux's mbr.bin into
>>> /dev/loop0 and using install-mbr binary, which isn't related to syslinux
>>> and provides the same
>>> functionality, coded in a different way.
>>>
>> How MBR is related to your case? Quoting your first mail: "using
>> chain.c32 module I can chainload into another partition's boot sector"
>>
>> If you look at chain code, it passes the same information using the same
>> method (partition entry pointed to by %SI register).
> I'm sorry; I think my first mail wasn't clear because I tried to explain
> the whole context.
> 
> In such disk there are more than one iso9660 partitions, so there is
> also some syslinux menu to select
> which one we want to boot to; that's why chain.c32. In the second mail I
> isolated the situation to one
> partition and an MBR code that boots into it, so no syslinux menu and no
> syslinux code is present, except
> for the mbr.bin that can be replaced with install-mbr being the behavior
> the same.
> 

MBR from install-mbr is using the same method (%SI points to partition
record). Try Microsoft MBR. Does it also work?