Dear coreboot folks,
to read the value of the BIOS Timer (section 2.11.4 of the BIOS and Kernel Developer’s Guide (BKDG) for the AMD Family 14 processors [1]), I am stuck at how to do that.
Below is the register description from the BKDG.
D0F0xE4_x0130_80F0 BIOS Timer ----------------------------- Reset: 0000_0000h. ----------------------------- Bits 31:0 Description MicroSeconds. Read-write; updated-by hardware. This field increments once every microsecond when the timer is enabled. The counter rolls over and continues counting when it reaches FFFF_FFFFh. A write to this register causes the counter to reset and begin counting from the value written.
I could not find any wrapper(?) function in the non-vendor code for that. In the vendor code directory `src/vendorcode/amd/agesa/f14/`, I found only `PcieRegisterRead`, which looks “hard” to access from outside.
$ git grep -i iocf8 $ git grep -i d0f0xe4 src/vendorcode/amd/agesa/f14
Any pointers to code already dealing with such indexed registers or instructions how to do that would help me very much.
Thanks,
Paul
[1] http://www.coreboot.org/Datasheets#AMD_Fam14 BKDG 43170 Rev 3.13 – February 17, 2012