DCMD_F3S_LOCKSSR

QNX SDP8.0Devctl and Ioctl CommandsDeveloper

Lock a secure silicon region

Synopsis:

#include <sys/dcmd_f3s.h>

#define DCMD_F3S_LOCKSSR    __DIOTF(_DCMD_F3S, F3S_LOCKSSR, uint32_t)

Arguments to devctl():

Argument Value
filedes A file descriptor that you obtained by opening /dev/fs0
dcmd DCMD_F3S_LOCKSSR
dev_data_ptr NULL, or a pointer to a uint32_t
n_bytes 0 or sizeof(uint32_t)
dev_info_ptr NULL

Description:

This command locks a secure silicon region. You can:

  • Lock the entire SSR. For this case, the data pointer should be NULL, and n_bytes should be 0.
  • Lock a specific region. For this case, the data pointer should not be NULL, and n_bytes should be 1. Currently, we use 1 byte to store the number of the region.

Input:

The number of the region to lock, or NULL to lock the entire OTP area.

Output:

None.

Example:

The Spansion S25FL QSPI flash supports multiple regions in the OTP (SSR) area. Each region can be locked separately:

  • Case 1: Lock the entire OTP area. In the call to devctl(), don't specify the data pointer or size parameter: 
    devctl(fd, DCMD_F3S_LOCKSSR, NULL, 0, NULL);
  • Case 2: Lock a specific region. Specify the data pointer and size parameters in the call to devctl(). For example, to lock region 17: 
    lock = 17;
devctl(fd, DCMD_F3S_LOCKSSR, &lock, 1, NULL);

See also:

DCMD_F3S_READSSR, DCMD_F3S_STATSSR, DCMD_F3S_WRITESSR

devctl() in the QNX OS C Library Reference

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