Re: [PATCH 0/1] pc-bios: Support List-Directed IPL from ECKD DASD

[Jared Rossi]

Hi,

Pinging this patch since v2.26.0 of s390-tools adds ECKD DASD list-directed IPL.
This patch set allows QEMU to utilize that new boot pointer format.
Any feedback about what needs to be changed for acceptance is much appreciated.

Thanks,
Jared Rossi

On 1/30/23 4:24 PM, Jared Rossi wrote:

> Add support for List-Directed IPL (LD-IPL) type pointers.
>
> We check for a boot record indicating LD-IPL and use it if it is valid,
> otherwise we use the CCW CDL or LDL format as usual. When a block is accessed
> during IPL the block number is first calculated based on the cylinder, head,
> and record numbers included in the block pointer; if LD-IPL has been initiated
> then each pointer will be interpreted using the new format.
>
> For simplicity, there is no choice presented to forcibly use CCW-IPL if LD-IPL
> is available.  Because both sets of pointers ultimately go to the same
> kernel/initrd, using CCW- or LD-IPL is transparent to the user.
>
> One aspect of the user experience that does change is the availability of the
> interactive boot menu when a loadparm is not specified.  For the existing
> CCW-IPL, when the user does not specify a loadparm they are presented with a
> list of boot options; however, this list is only written in the old style
> pointers.  Therefore, if no loadparm is specified, and LD-IPL is supported, the
> default boot option will be used automatically.
>
> Jared Rossi (1):
>   pc-bios: Add support for List-Directed IPL from ECKD DASD
>
>  pc-bios/s390-ccw/bootmap.c | 157 ++++++++++++++++++++++++++++---------
>  pc-bios/s390-ccw/bootmap.h |  30 ++++++-
>  2 files changed, 148 insertions(+), 39 deletions(-)
>
>