topic Re: Memory read/write utility for P5040DS-PB in P-Series

Memory read/write utility for P5040DS-PB

rammurmu — Fri, 06 Jan 2017 09:50:55 GMT

Hi,

Can anyone share the memory read/write utility for P5040DS-PB. I do have devmem2.c ( as attached ) that works fine for other targets. However it is not working for P5040.

The function "mmap" fails with EPERM [Operation not permitted] error. The "prot" argument was changed to "PROT_READ | PROT_WRITE | PROT_EXEC" , still it shows the same error[Operation not permitted].

Thanks and Regards

Ram

Original Attachment has been moved to: devmem2.c.zip

Re: Memory read/write utility for P5040DS-PB

rammurmu — Tue, 10 Jan 2017 04:36:30 GMT

Hi,

I found the way to ready using the attached devmem2.c. The crux is address argument need to passed as 36 bit address, i.e. CCSRBAR + ADDR OFFSET should be 36bit. The mmap function will return correct mapping after that.

For example to read the BR0 ( OFFSET = 0x124000) ( CCSRBARL = 0xFE000000 , CCSRBARH = 0xF0000000 ). The final address of BR0 is 0xFFE124000

Thanks

Ram

Re: Memory read/write utility for P5040DS-PB

Pavel — Wed, 11 Jan 2017 02:08:28 GMT

mmap returns an MMAP_FAIL and sets EPERM as errno when trying to map a file from a partition that is mounted with noexec option in RHEL-4.8
The problem occurs only for a 32 bit application running on a 64 bit system

Have a great day,
Pavel Chubakov

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------