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RE: I write a patch for Japanese NEC i386 old computers.

From: Hitoshi Ozeki
Subject: RE: I write a patch for Japanese NEC i386 old computers.
Date: Wed, 11 Apr 2007 03:56:26 +0900

Hello, all.

Okuji-san wrote about the different(128-2048 bytes) sector-size support:
         I think there are two different ways to address this issue. One way
is to use  
         variable sector size. This looks elegant, but this affects the disk
         API very much. The other is to use fixed sector size, as it is for
now, but 
         align boundaries at a device driver level. The latter way is used
for GRUB 
         Legacy to support CDROM, and it works well.
         I don't know which way is better. What do you think?

Maybe, The implement of GRUB legacy comes from PC architecture.
On the PC architecture BIOS, regards 512 bytes as a block. And
BIOS requires a number of blocks.

On NEC PC-9800 series, Disk BIOS requires data size in byte,
not a number of sectors. Data size must be divisible by sector size.
And the partition table starts with LBA sector 1, and its length
equals to sector size.

It's too difficult to change the API.

I think to set the GRUB_DISK_SECTOR_SIZE as the least.
(As far as I know, The least hardware sector size is 128 bytes.)
and add the variable to 'struct grub_disk'. Its variable stores 
 sector size(blocks per sector).

In this case, A name of 'GRUB_DISK_SECTOR_SIZE' does not match
the actual situation. I'd like its name changed.

 Hitoshi Ozeki address@hidden

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