linux hang on i.mx35 board, a sdma problem?
alexander.stein at systec-electronic.com
Thu Oct 7 10:23:29 EDT 2010
I'm currently developing on an i.mx35 board (http://www.ic-
board.de/product_info.php?info=p159_ICnova-i-MX353-OEM.html) (I use the
mx35_pdk config for linux kernel)
and noticed a strange behavior. If I run it while openocd is attached to JTAG
linux stops/seem to stop during boot after initializing FEC. But if I stop the
execution and attach gdb I can see it loops inside default_idle. After
removing the fec driver the same goes until the first few chars printed from
busybox init (run from initramfs).
If I don't attach openocd to JTAG, the system boots fine, but I cannot attach
openocd to the running linux system.
I have to admit I removed the DMA device drivers, because otherwise linux
doesn't seem to start at all.
Is this problem related to the sdma unit? I read something from the manual
sdma can be blocked from jtag access, maybe this breaks the chain.
If not, what could be the cause, that the system is not starting properly, but
the idle loop is executed?
PS: I tested eariler on the BSP (2.6.34) from in-circuit, but the test above
is using linux-2.6.36-rc7.
More information about the linux-arm-kernel