On Mon May 26, 2014 at 20:55:19 +0200, ba_f wrote:

i try to access some peripheral on my platform. But i get page faults when writing to the peripheral at 0x41220000:

MOE: Hello world MOE: found 505476 KByte free memory MOE: found RAM from 6f000 to 1f000000 MOE: allocated 495 KByte for the page array @0x9f000 MOE: virtual user address space [0-bfffffff] MOE: rom name space cap -> [C:501000] BOOTFS: [116d000-116d117] [C:503000] periTest.cfg BOOTFS: [116e000-116e1aa] [C:504000] periTest.io BOOTFS: [116f000-1188494] [C:505000] l4re BOOTFS: [1189000-129673c] [C:506000] io BOOTFS: [1100000-1152c0c] [C:507000] ned BOOTFS: [1153000-116c5e4] [C:508000] periTest MOE: cmdline: moe rom/periTest.cfg MOE: Starting: rom/ned rom/periTest.cfg MOE: loading 'rom/ned' Ned says: Hi World! Ned: loading file: 'rom/periTest.cfg'

periTest| L4Re[rm]: unhandled write page fault @41220000 pc=1000294 periTest| L4Re: unhandled exception: pc=0x1000294

You cannot just directly access the physical memory address. You first have to make it visible in your program. Please use the l4io_request_iomem() function for that. And then use the address returned by that function to access the device memory.

Here is my CFG. My io-file looks like the one here https://os.inf.tu-dresden.de/L4Re/doc/io.html

## cfg require("L4");

local loader = L4.default_loader;

local io_buses = { FOODEVICE = loader:new_channel(); };

loader:start({ caps ={ FOODEVICE = io_buses.FOODEVICE:svr(), }, }, "rom/periTest rom/periTest.io" ); ## end CFG

That won't work. You need something like this, esp. you need to start io as well.

local loader = L4.default_loader; local io_buses = { vbus1 = loader:new_channel(); };

loader:start({ caps = { client1 = vbus1:svr(), icu = L4.Env.icu, sigma0 = L4.cast(L4.Proto.Factory, L4.Env.sigma0):create(L4.Proto.Sigma0), }}, "rom/io rom/periTest.io");

loader:start({ caps = { vbus = vbus1 }}, "rom/periTest");

An example is for example in l4/conf/examples/x86-fb.cfg.

Adam