[U-Boot-Users] Little endian

[Leon KUKOVEC]

Hello Ed,

On Thu, 27 Nov 2003, Ed Okerson wrote:

> What partition types are you using?  I am trying to do a partition table
> with some linux and at least one FAT16 partition, but even without the FAT
> partition the system was showing a single partition as:

I have setup two partitions using fdisk on target. fdisk however shows some
warnings, but I suspect this is a bug in busybox's fdisk (I might be wrong).

Here's what I get:

------------ paste --------------
# fdisk /dev/discs/disc0/disc
 /dev/ide/host0/bus0/target0/lun0: p1 p2

Command (m for help): p

Disk /dev/discs/disc0/disc: 128 MB, 128450560 bytes
8 heads, 32 sectors/track, 980 cylinders
Units = cylinders of 256 * 512 = 131072 bytes

                Device Boot    Start       End    Blocks   Id  System
/dev/discs/disc0/part1               1          77        9840    c  Win95 FAT32
 (LBA)
/dev/discs/disc0/part2              78         980      115584   83  Linux
/dev/discs/disc0/part3               1           1           0    0  Empty
Partition 3 has different physical/logical beginnings (non-Linux?):
     phys=(0, 0, 0) logical=(0, 0, 1)
Partition 3 has different physical/logical endings:
     phys=(0, 0, 0) logical=(16777215, 7, 32)
Partition 3 does not end on cylinder boundary.

Command (m for help):
--------- end of paste -----------

First partition is VFAT (primary), second is Linux(primary). I have not
tested extended partitions since I did not find any reason for having
them - currently.

However U-Boot ide part shows two partitions:

------------ paste --------------
WEP> ide reset

Reset IDE: SanDisk SDP 5/3 0.6
            Fixed Disk Card
            IDE interface
            [silicon] [unique] [single] [sleep] [standby] [idle] [low power]
Bus 0: OK
  Device 0: Model: SanDisk SDCFB-128 Firm: Vdg 1.25 Ser#: 1181701L00X20512
            Type: Removable Hard Disk
            Capacity: 122.5 MB = 0.1 GB (250880 x 512)
WEP> ide part

Partition Map for IDE device 0  --   Partition Type: DOS

Partition     Start Sector     Num Sectors     Type
    1                   32           19680       c
    2                19712          231168      83
WEP>
--------- end of paste -----------

I have not investigated which one is wrong/correct because I can access
primary - VFAT - partition on both systems and also on a PC. After I finish
VFAT write support in U-Boot, I might go and see which "fdisk" is wrong or
correct.

> So this morning I started going through and figuring exactly what that
> meant.  It appears that the first line shows up if the boot sector of the
> compact flash card has a DOS boot signature that is what you get.  So
> apparently some idiot (probably me) at some point in time formated that CF
> card in a DOS machine with the /s option and it happily copied a DOS boot
> record into the beginning of the card.  Boy do I feel stupid.  So I popped
> the CF into a linux machine and typed "cat /dev/zero > /dev/hdg" re-ran
> fdisk to create my partitions, and now u-boot happily reports:
>
> DbAu1x00 # ide part
>
> Partition Map for IDE device 0  --   Partition Type: DOS
>
> Partition     Start Sector     Num Sectors     Type
>     1                   32            4576      83
>     2                 4608            4608      83
>     3                 9216          492544      83
> DbAu1x00 #
>
> Which is what I wanted.  I have been using #if defined(CONFIG_AU1X00)
> around my code mods, but it sounds like your changes and my changes are
> about the same in the end, so perhaps we should come up with another
> define for ENDIAN_CHALLENGED or something.

I think we should stick to defines that are already used. The endian issues
should be wraped with __LITTLE_ENDIAN or __BIG_ENDIAN, specific board issues
with CONFIG_AU1X00 or CONFIG_WEPEP250 in my case. I have already submitted
the patch for PCMCIA on PXA and that patch fixes the issues with
Firmware Revision, Model Number and lba_capacity wrapped with endian #ifdef.

When Wolfgang gets some time for U-Boot and examines the patch and hopefully
applies it, you will be able to distinguish between "common" patch and your
board specific one.

> It helped a lot.  Thanks.  I guess the moral of the story is when you are
> having problems, make sure there isn't a short between the keyboard and
> the chair first. :)

Keep up the good work!

-- 

Best Regards,
	Leon.