DCMD_MMCSD_WRITE_PROTECT

QNX SDP8.0Devctl and Ioctl CommandsDeveloper

Clear or set write protection

Synopsis:

#include <hw/dcmd_sim_mmcsd.h>

#define DCMD_MMCSD_WRITE_PROTECT __DIOTF(_DCMD_CAM, _SIM_MMCSD + 1, struct _mmcsd_write_protect)

Arguments to devctl():

Argument Value
filedes A file descriptor that you obtained by opening the device
dcmd DCMD_MMCSD_WRITE_PROTECT
dev_data_ptr A pointer to a MMCSD_WRITE_PROTECT structure (see below)
n_bytes sizeof(MMCSD_WRITE_PROTECT)
dev_info_ptr NULL

Description:

This command clears or sets write protection.

Input:

A filled-in MMCSD_WRITE_PROTECT structure: 

typedef struct _mmcsd_write_protect {
        uint32_t                action;
        uint32_t                mode;
        uint64_t                lba;
        uint64_t                nlba;
        uint64_t                rsvd2;
} MMCSD_WRITE_PROTECT;

The members include:

action
The action to take; one of:
  • MMCSD_WP_ACTION_CLR — remove write protection
  • MMCSD_WP_ACTION_SET — set write protection
mode
The bits include:
  • MMCSD_WP_MODE_PWR_WP_EN — apply power-on period protection
lba
The logical block address to start at.
nlba
The number of logical blocks.

Output:

None.

See also:

devctl() in the QNX OS C Library Reference

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