raspberry3_bare/fb.c
2022-03-17 22:35:47 +01:00

67 lines
2.1 KiB
C

#include "fb.h"
#include "mbox.h"
#include "uart.h"
#include "utils.h"
#include <stdint.h>
#define MBOX_TAG_FBALLOC 0x40001
#define MBOX_TAG_FBGETPITCH 0x40008
#define MBOX_TAG_FBSETPHYS 0x48003
#define MBOX_TAG_FBSETVIRT 0x48004
#define MBOX_TAG_FBSETDEPTH 0x48005
#define MBOX_TAG_FBSETPIXORD 0x48006
#define MBOX_TAG_FBSETOFF 0x48009
unsigned char *init_fb(struct fbst *fb) {
// sending many tags at once
mbox[0] = 35 * 4;
mbox[1] = MBOX_REQUEST;
mbox[2] = MBOX_TAG_FBSETPHYS; // set phy wh
mbox[3] = 8;
mbox[4] = 0;
mbox[5] = 1920; // FrameBufferInfo.width
mbox[6] = 1080; // FrameBufferInfo.height
mbox[7] = MBOX_TAG_FBSETVIRT; // set virt wh
mbox[8] = 8;
mbox[9] = 0;
mbox[10] = 1920; // FrameBufferInfo.virtual_width
mbox[11] = 1080; // FrameBufferInfo.virtual_height
mbox[12] = MBOX_TAG_FBSETOFF; // set virt offset
mbox[13] = 8;
mbox[14] = 0;
mbox[15] = 0; // FrameBufferInfo.x_offset
mbox[16] = 0; // FrameBufferInfo.y.offset
mbox[17] = MBOX_TAG_FBSETDEPTH; // set depth
mbox[18] = 4;
mbox[19] = 0;
mbox[20] = 32; // FrameBufferInfo.depth
mbox[21] = MBOX_TAG_FBSETPIXORD; // set pixel order
mbox[22] = 4;
mbox[23] = 0;
mbox[24] = 1; // RGB, not BGR preferably
mbox[25] = MBOX_TAG_FBALLOC; // get framebuffer, gets alignment on request
mbox[26] = 8;
mbox[27] = 0;
mbox[28] = 4096; // FrameBufferInfo.pointer
mbox[29] = 0; // FrameBufferInfo.size
mbox[30] = MBOX_TAG_FBGETPITCH; // get pitch
mbox[31] = 4;
mbox[32] = 0;
mbox[33] = 0; // FrameBufferInfo.pitch
mbox[34] = MBOX_TAG_LAST;
if (mbox_call(MBOX_CH_PROP, mbox) == 0 && mbox[20] == 32 && mbox[28] != 0) {
mbox[28] &= 0x3FFFFFFF; // convert GPU address to ARM address
fb->width = mbox[5]; // get actual physical width
fb->height = mbox[6]; // get actual physical height
fb->pitch = mbox[33]; // get number of bytes per line
fb->isrgb = mbox[24]; // get the actual channel order
fb->fbp = (void *)((unsigned long)mbox[28]);
} else {
puts("Unable to set framebuffer!\r\n");
return 0;
}
return fb->fbp;
}