Andrew Thomas wrote:
> 1.33c gave me the option to boot from a CF card - as it would with 1.33.

I'm not sure I understand your response.


The only storage I have installed is the CF card.  I have it working 
providing I make the /boot partition fit on the first cylinder (the 
imaginary first cylinder when you convert to CHS geometry).  So there is 
no doubt that plain 1.33 supports a CF card for booting.

The only background reading I can find is that 1.33b/1.33c were produced 
in response to some issues/workaround with hardware production.  Which 
might explain why no release notes since only those affected need to 
upgrade ?

Nowhere has it been stated that any fixes/changes have been made in 
1.33c that affect this particular problem.


Infact I should ask, does anybody have a > 8Gb Compact Flash with GRUB 
working without the 1 cylinder restriction ?

The 8Gb limit comes from the C/H/S geometry returned by comBIOS for my 
flash being 1946 cylinders, 255 heads, 63, sectors.  This is larger than 
the 1024 cylinder limit.

That limit for the C/H/S range of 0/0/1 to 1023/254/63 is 1024*255*63 
sectors or 8225280 KiB or 8032.5 MiB or 7.8442 GiB or 8.422 Gb.  So as 
flash maybe rated in Gb not GiB it needs to be larger than 8 Gb to be 
relevant.

I do not have smaller CF cards to test and see what C/H/S geometry 
net5501 returns for say a 4Gb or 2Gb or 1Gb flash card.  It is possible 
due to that geometry choice the particular bug I am being hit with does 
not show itself.



Also does comBIOS 1.33 (and later versions) provide these BIOS interfaces :


[INT 0x13  AH=0x41  BX=0x55aa]  is used by GRUB for LBA mode check, it 
expects a return of [Carry flag reset, BX=0xaa55] on return to indicate 
LBA mode is supported (i.e. function AH=0x42 is supported for LBA mode).

[INT 0x13  AH=0x42  various other registers used] is used by GRUB for 
LBA read sectors from disk into memory.



Thanks,

Darryl
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