Set the Floating Point Data registers with the values provided for the process associated with the file descriptor.

#include <sys/procfs.h>

#define DCMD_PROC_SETFPREG   __DIOT(_DCMD_PROC, __PROC_SUBCMD_PROCFS + 13, procfs_fpreg)

The arguments to devctl() are:

Argument Value
filedes A file descriptor for the process. You must have opened the file descriptor for writing.
dev_data_ptr A pointer to a procfs_fpreg structure
n_bytes sizeof(procfs_fpreg)
dev_info_ptr NULL

The argument is a pointer to a procfs_fpreg structure (see debug_fpreg_t in <sys/debug.h>) that specifies the values of the Floating Point Data registers. For example:

procfs_fpreg my_fpreg;

/* Set the members of my_fpreg as required. */
devctl( fd, DCMD_PROC_SETFPREG, my_fpreg, sizeof(procfs_fpreg),

To get the Floating Point Data registers, use DCMD_PROC_GETFPREG.