Writes to the region may be combined or performed out of order.
Writes to the region are committed synchronously.
Writes to the region are committed asynchronously.
The region cannot be written to.
Memory ranges are described by .Vt struct mem_range_desc :
u_int64_t mr_base; /* physical base address */
u_int64_t mr_len; /* physical length of region */
int mr_flags; /* attributes of region */
In addition to the region attributes listed above, the following flags may also be set in the mr_flags field:
The regions base address cannot be changed.
The regions length cannot be changed.
The region is believed to have been established by the system firmware.
The region is currently active.
We believe the region to be invalid or otherwise erroneous.
The region cannot be disabled.
The region is currently owned by another process and may not be altered.
Operations are performed using struct mem_range_op:
struct mem_range_desc *mo_desc;
The MEMRANGE_GET ioctl is used to retrieve current memory range attributes. If mo_arg is set to 0, it will be updated with the total number of memory range descriptors. If greater than 0, the array at mo_desc will be filled with a corresponding number of descriptor structures, or the maximum, whichever is less.
The MEMRANGE_SET ioctl is used to add, alter and remove memory range attributes. A range with the MDF_FIXACTIVE flag may not be removed; a range with the MDF_BUSY flag may not be removed or updated.
mo_arg should be set to MEMRANGE_SET_UPDATE to update an existing or establish a new range, or to MEMRANGE_SET_REMOVE to remove a range.