NAME
amdmsr —
access MSRs on certain AMD Geode LX
systems
SYNOPSIS
amdmsr0 at mainbus?
DESCRIPTION
The amdmsr device provides access to the
Model Specific Registers (MSRs) on systems with an AMD Geode LX CPU and
graphics processor.
IOCTL INTERFACE
MSRs can be read or written via
ioctl()
calls performed on /dev/amdmsr. Declarations and
data types are to be found in
⟨machine/amdmsr.h⟩.
Read or write requests are performed using:
struct amdmsr_req {
u_int32_t addr; /* 32-bit MSR address */
u_int64_t val; /* 64-bit MSR value */
};
The RDMSR ioctl is used to read an MSR register.
The WRMSR ioctl is used to write an MSR register.
SEE ALSO
HISTORY
amdmsr support was added in
OpenBSD 4.4.