Is there a way to extract the “die-id” of the Beagleboard xM without having to switch to a new Linux kernel?
On the xM revC, the 2.6.32 kernel shipped with Angstrom always says “0000000000000000” in the /proc/cpuinfo.
After installing Angstrom 2011.03 on the Beagleboard xM, I found that the Linux kernel 2.6.32 is not able to read the “die id #” (the “cat /proc/cpuinfo” always says “0000000000000000”).
The uBoot was able to read it. So I used its “optargs” parameter (default: empty) which is passed to the command-line Linux kernel parameters, setting it in the “uenvcmd” parameter (default: empty) which is executed before the kernel starts.
That is, I added this line in the uEnv.txt:
uenvcmd=“setenv optargs dieid=${dieid#}”
The Linux kernel does not complain about that “dieid” unknown parameter. My software can then extract it from /proc/cmdline (that will show something like: “console=ttyS2,115200n8 dieid=97f40b939f18c00b01e2a741e6c49fb1 mpurate=1000 buddy=none…”).