The Renaissance can be configured at either the ``internal'' address (frame buffer address 0x200000, control register space address 0x560000) or at an external select code less than 32. At the internal address it will be the ``preferred'' console device (see cons(4)). The hardware installation manual describes the procedure for setting these values.
A user process communicates to the device initially by means of ioctl(2) calls. For the HP-UX ioctl(2) calls supported, refer to HP-UX manuals. The BSD calls supported are:
Get info about device, setting the entries in the grfinfo structure, as defined in Aq Pa hpdev/grfioctl.h . For the standard 98720, the number of planes should be 4. The number of colors would therefore be 15, excluding black. If one 98722A frame buffer board is installed, there will still be 4 planes, with the 4 planes on the colormap board becoming overlay planes. With each additional 98722 frame buffer board 4 planes will be added up to a maximum of 32 planes total.
Turn graphics on by enabling CRT output. The screen will come on, displaying whatever is in the frame buffer, using whatever colormap is in place.
Turn graphics off by disabling output to the CRT The frame buffer contents are not affected.
Map in control registers and framebuffer space. Once the device file is mapped, the frame buffer structure is accessible. The structure describing the 98720 is defined in hpdev/grf_rbreg.h
struct rboxfb *rbox; u_char *Addr, frame_buffer; struct grfinfo gi; int disp_fd; disp_fd = open("/dev/grf0",1); if (ioctl (disp_fd, GRFIOCGINFO, &gi) < 0) return -1; (void) ioctl (disp_fd, GRFIOCON, 0); Addr = (u_char *) 0; if (ioctl (disp_fd, GRFIOCMAP, &Addr) < 0) { (void) ioctl (disp_fd, GRFIOCOFF, 0); return -1; } rbox = (rboxfb *) Addr; /* Control Registers */ frame_buffer = (u_char *) Addr + gi.gd_regsize; /* Frame buffer memory */
For extensive code examples using the Renaissance, see the X device dependent source.