HP-UX Reference (11i v3 07/02) - 7 Device (Special) Files, 9 General Information, Index (vol 10)

f
framebuf(7) framebuf(7)
needs to be refreshed. The window image is then a superset of the rectangle being
updated, and might thus have different dimensions. The
skipcount specifies the
portion of the row in the larger window image that is excluded from the rectangle.
Thus,
linelength plus skipcount would be the number of bytes in each row of
the larger window image array.
If a particular framebuffer device supports this system call, the CRT_DMA_OUTPUT
flag in the crt_attributes
field of the crt_frame_buffer_t
structure is
set. Some framebuffer devices supporting DMA might restrict alignment of the vari-
ous parameters, and are specified in the DEPENDENCIES section below. The kernel
ensures that these restrictions are obeyed, and if they are not the system call will fail
and set
errno to [EINVAL].
It is the responsibility of the application to guarantee that the system’s physical
memory is up-to-date by flushing the processor’s data cache. One should use the
GCDMA_DATAFLUSH
ioctl to ensure that the data is consistent before initiating a
DMA transfer.
GCDMA_DATAFLUSH
Flush the specified data from the processor’s data cache to the system’s main memory.
This system call is intended to be used before DMA to ensure that an up-to-date ver-
sion of the data is transferred to the framebuffer or to control space.
The parameters for the flush are passed in a
crt_flush_t data structure, which
includes the following fields:
char *flush_addr; /* Starting address of data
to be flushed */
int flush_len; /* Number of bytes to flush */
The kernel ensures that the flush_len bytes starting at flush_addr are con-
sistent in main memory with respect to the cache.
GCSLOT Provide pertinent information about the calling process’s participation in the system-
wide graphics locking mechanism (see the discussion under GCLOCK above). The
GCSLOT request does not carry out any actual locking functionality. The lock infor-
mation is returned to the calling process in a crt_gcslot_t data structure. The
parameter is defined as crt_gcslot_t *arg;. The crt_gcslot_t data
structure is defined in the file <sys/framebuf.h>
.
GCSTATIC_MAP Prevent the Internal Terminal Emulator (ITE) from modifying the device’s color map.
GCVARIABLE_MAP
Allow the Internal Terminal Emulator (ITE) to modify the device’s color map.
DEPENDENCIES
When requesting GCMAP, the parameter arg is ignored and should be set to 0.
All supported ITEs ignore the frame buffer lock for output.
ERRORS
[EAGAIN] The operation would result in suspension of the calling process, but the request was either
GCLOCK_NOWAIT or GCLOCK_BLOCKSIG_NOWAIT.
[EBUSY] Attempted to lock the device, which is already locked by the same process.
[EINTR] A call to ioctl() was interrupted by a signal.
[EINVAL] An invalid ioctl() command was made.
[ENODEV] Attempted to use read() or write() system calls on the device.
[ENOMEM] Sufficient memory for mapping could not be allocated.
[ENOSPC] Required resources for mapping could not be allocated.
[ENXIO] The minor number on the device file refers to a nonexistent device.
[EPERM] Requested GCUNLOCK ioctl() command, but the device was locked by a different pro-
cess.
HP-UX 11i Version 3: February 2007 − 4 − Hewlett-Packard Company 47