[U-Boot-Users] patch for CFI flash driver

[Brad Kemp]

Josh,
I re-ran the test to fast (use mm instead of nm), the results are be
=> md 0xe8180000
e8180000: ff060708 0ffa8f64 090a0b0c 0d0e0f10    .......d........
e8180010: 11121314 15161718 0000ffff 0ffa8f64    ...............d
e8180020: ffffffff ffffffff ffffffff ffffffff    ................
e8180030: ffffffff ffffffff ffffffff ffffffff    ................


> -----Original Message-----
> From: Brad Kemp 
> Sent: Monday, February 23, 2004 4:42 PM
> To: 'Josh Fryman'
> Cc: u-boot-users at lists.sourceforge.net
> Subject: RE: [U-Boot-Users] patch for CFI flash driver
> 
> 
> Josh,
> I think the solution to the 8 bit x8/x16 problem is to 
> separate the query command matching from the commands that
> are written to the flash. Not having an 8bit x8/x16 
> implementation has made it hard for me to work this out. 
> 
> As for your patch. While it does let me copy odd amounts of 
> data at unaligned boundaries (something the driver did not 
> previosly do). The results I get are not correct. Below I 
> have filled memory with 010203040506... And copied part of it 
> to a previously erase sector in flash.
> 
> 
> => nm 0x140000
> 00140000: ffffffff ? 01020304
> 00140000: 01020304 ? 05060708
> 00140000: 05060708 ? 090a0b0c
> 00140000: 090a0b0c ? 0d0e0f10
> 00140000: 0d0e0f10 ? 11121314
> 00140000: 11121314 ? 15161718
> 00140000: 15161718 ? 191a1b1c
> 00140000: 191a1b1c ? 1d1e1f20
> 00140000: 1d1e1f20 ? 21222324
> 00140000: 21222324 ? 25262728
> 00140000: 25262728 ? 292a2b2c
> 00140000: 292a2b2c ? 2d2e2f30
> 00140000: 2d2e2f30 ? .
>  
> => cp.b 0x140005 0xe8180003 0x15
> Copy to Flash... done
> => md 0xe8180000
> e8180000: ffffffff 0ffe99cc ffffffff ffffffff    ................
> e8180010: ffffffff ffffffff 0000ffff 0ffe99cc    ................
> e8180020: ffffffff ffffffff ffffffff ffffffff    ................
> e8180030: ffffffff ffffffff ffffffff ffffffff    ................
> e8180040: ffffffff ffffffff ffffffff ffffffff    ................
> 
> > -----Original Message-----
> > From: Josh Fryman [mailto:fryman at cc.gatech.edu] 
> > Sent: Monday, February 23, 2004 3:29 PM
> > To: Brad Kemp
> > Cc: u-boot-users at lists.sourceforge.net
> > Subject: Re: [U-Boot-Users] patch for CFI flash driver
> > 
> > 
> > hi brad,
> > 
> > > I think this patch will break 8bit x8/x16 implementions. 
> > 
> > not surprising :) i was worried i was breaking things when 
> i did that
> > solution, but wasn't sure how it would break.
> > 
> > > The reports I got back from the field indicated that the 
> port width
> > > had to be halved to get flash writes to work sucessfully on 8bit  
> > > x8/x16 implementations. I think there is a better solution to the 
> > > problem than the one that was originally implemented.
> > 
> > i'm almost certain of it.  i don't design well after a long day of
> > debugging problems.
> > 
> > do you have a nice solution to the problem?  or do you just have the
> > same "there has to be a better way" feeling about it that i do?  i 
> > can go back and try to actually design a proper solution, but i was 
> > hoping the "fix" would give you the insight needed that 
> you'd have an
> > elegant solution...
> > 
> > cheers,
> > 
> > -josh
> > 
> > (another idea was to malloc a sufficiently large buffer, read in
> > current flash contents, do the update to memory, then call the
> > existing -unhacked- routines to write back to flash on nice 
> > boundaries to kill padding problems and alignment issues... but this
> > seemed like an even worse approach.)
> > 
> > 
>