[U-Boot-Users] Spartan FPGA patch

[Aggelos Manousarides <amanous@inaccessnetworks.com>]

Wolfgang Denk wrote:
> In message <472752F9.9000307@inaccessnetworks.com> you wrote:
>> The following patch fixes a bug in the slave serial programming mode for 
>> the xilinx spartan2 FPGA. A "char val" is declared, but it is used as a 
>> signed char. The check for negative value (<0) is always true on arm, or 
>> any other platform in which the char is not signed by default. As a 
>> result the FPGA cannot be programmed.
> 
> I have to admit that I hate to see "signed  char"  in  the  code.  Is
> there  any  special  reaso why "val" has to be a "char" type? Why not
> making it an "int" ?

Another way to do this safely is to declare it as an "unsigned char" and 
instead of doing "val < 0", do "val & 0x80". I don't like the current 
code either. Shifting a signed char and testing for negativity is 
definitely not the best way to test that the MSB is set.

--
Angelos Manousaridis