2008-05-14 14:34:13 Memory Protection
Henning Manteuffel (GERMANY)
Message: 55833
I connected an FPGA to the Blackfin address/data bus for accelerating arithmetic computations.
Is there a way to unprotect certain addresses in user space so that the FPGA can be accessed directly without a device driver? Changing entries in the DCPLB address and data registers did not work, an exception is still thrown.
QuoteReplyEditDelete
2008-05-15 10:19:57 Re: Memory Protection
Mike Frysinger (UNITED STATES)
Message: 55862
by default, all the async memory banks are usable from userspace, so there isnt anything for you to change. i just tested by setting a pointer to 0x20000000 and reading data frorm userspace and it worked fine.
please post the crash message you're getting as well as information about your system (kernel/toolchain version/etc...)
QuoteReplyEditDelete
2008-05-22 08:20:14 Re: Memory Protection
Henning Manteuffel (GERMANY)
Message: 56140
I used the wrong toolchain (2007R1.1). Downgrading to 2007R1 eleminated the error. The toolchain seemed to be too new for the kernel.
QuoteReplyEditDelete
2008-05-22 10:13:08 Re: Memory Protection
Robin Getz (UNITED STATES)
Message: 56146
Henning:
Toolchain, kernel and bootloader are three pieces of the same puzzle. You can
not just upgrade/downgrade one - you need to do all three.
https://docs.blackfin.uclinux.org/doku.php?id=faq
Why do I need to use the same version of toolchain / kernel / uClibc /
U-boot / uClinux-dist?