[DNX#2006033142000972] [U-Boot-Users] SPI support in U-boot
DENX Support System
support at denx.de
Fri Mar 31 23:50:40 CEST 2006
inside the automatic U-Boot patch tracking system a new ticket
[DNX#2006033142000972] was created:
> Hello Wolfgang,
> Wolfgang Denk wrote:
> >Good catch!
> >>Is that OK? I also noticed the same mechanism being used in the
> >>FPGA-related code.
> >I think your interpretation is correct.
> And? :)
> OK, so here are the questions:
> 1. Should the code be left like that (i.e. some parts are executing
> from FLASH instead of RAM) because it "just works for me" or it is
> not acceptable to code like that?
> 2. What is the right way to do that: to use an uninitialized variable
> and initialize it from board_misc_init_r with something like
> myfuncptr = &myfunc + bd->reloc_off
> or to have initialized variable myfuncptr = myfunc and simply do
> myfuncptr += bd->reloc_off in board_misc_init_r?
> 3. Ironically enough, I noticed that fpga_init() is declared like
> extern void fpga_init( ulong reloc_off ), but all the
> implementations use void fpga_init(void)!
> 4. Wouldn't it make sense to add a small section to README,
> explaining how to use function pointer tables in U-boot (not sure
> how much sense it makes to begin with).
> >It would be nice to preserve the currnt behaviour, so a patch should
> >try to implement the required changes for all boiards. Testing will
> >have to be performed by the respective board maintainers, of course.
> This seems to be difficult, since the current interface only allows you
> to assert/de-assert a particular chipselect, but not to query which one
> is currently active (so that "sspi" command could restore what was
> before it. I guess, I can do three things:
> 1. Extend sspi command, so that if there is only 1 arg, chip_select,
> it will simply assert it and do nothing else
> 2. Hope, that people who use "eeprom" command don't really care about
> "sspi" so far, otherwise it would be working!
> 3. Document the changes.
Your U-Boot support team
More information about the U-Boot