[U-Boot-Users] How do you test a bit set/clear from U-Boot command line/script?

Tolunay Orkun listmember at orkun.us
Wed Apr 26 22:50:16 CEST 2006

Wolfgang Denk wrote:
> In message <444FD06D.4060309 at orkun.us> you wrote:
>> Within a u-boot script (to be executed by autoscr command), I need to 
>> read a GPIO port and if a particular GPIO bit is set execute some 
>> conditional commands. I am not sure how to do this with test/itest 
>> commands. Any ideas?
> This is obviously highly hardware specific.

I am not asking anything about hardware. Forget I said GPIO. Let's say a 
value in general memory space. It could be in ram or flash....

I know I can compare a simple value using itest command. e.g.

itest *4000 -eq 1234 && echo 'Addr 4000 contains 1234'

Now my problem is how can I test a bit of 32 bit quantity (say bit 4) 
stored at location 4000? This is a question about general hush/u-boot 
shell capability? It is a generic question...

Best regards,

More information about the U-Boot mailing list