Fix several issues in framebuffer_service
-supports fb's with x and y offsets
-dumps the front buffer (instead of just the low end of the buffer)
-switch from mmap to read/write, for fb's with very large offsets
Change-Id: Id560790c9661f7cc3b4350a44cc29f0104831e85
Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
diff --git a/adb/framebuffer_service.c b/adb/framebuffer_service.c
index 65cb20a..cb48d41 100644
--- a/adb/framebuffer_service.c
+++ b/adb/framebuffer_service.c
@@ -28,18 +28,17 @@
#include <sys/mman.h>
/* TODO:
-** - grab the current buffer, not the first buffer
** - sync with vsync to avoid tearing
*/
void framebuffer_service(int fd, void *cookie)
{
struct fb_var_screeninfo vinfo;
- int fb;
- void *ptr = MAP_FAILED;
- char x;
+ int fb, offset;
+ char x[256];
unsigned fbinfo[4];
+ unsigned i, bytespp;
fb = open("/dev/graphics/fb0", O_RDONLY);
if(fb < 0) goto done;
@@ -47,24 +46,34 @@
if(ioctl(fb, FBIOGET_VSCREENINFO, &vinfo) < 0) goto done;
fcntl(fb, F_SETFD, FD_CLOEXEC);
- fbinfo[0] = 16;
- fbinfo[1] = vinfo.xres * vinfo.yres * 2;
+ bytespp = vinfo.bits_per_pixel / 8;
+
+ fbinfo[0] = vinfo.bits_per_pixel;
+ fbinfo[1] = vinfo.xres * vinfo.yres * bytespp;
fbinfo[2] = vinfo.xres;
fbinfo[3] = vinfo.yres;
- ptr = mmap(0, fbinfo[1], PROT_READ, MAP_SHARED, fb, 0);
- if(ptr == MAP_FAILED) goto done;
+ /* HACK: for several of our 3d cores a specific alignment
+ * is required so the start of the fb may not be an integer number of lines
+ * from the base. As a result we are storing the additional offset in
+ * xoffset. This is not the correct usage for xoffset, it should be added
+ * to each line, not just once at the beginning */
+ offset = vinfo.xoffset * bytespp;
- if(writex(fd, fbinfo, sizeof(unsigned) * 4)) goto done;
+ offset += vinfo.xres * vinfo.yoffset * bytespp;
- for(;;) {
- if(readx(fd, &x, 1)) goto done;
- if(writex(fd, ptr, fbinfo[1])) goto done;
+ if(writex(fd, fbinfo, sizeof(fbinfo))) goto done;
+
+ lseek(fb, offset, SEEK_SET);
+ for(i = 0; i < fbinfo[1]; i += 256) {
+ if(readx(fb, &x, 256)) goto done;
+ if(writex(fd, &x, 256)) goto done;
}
+ if(readx(fb, &x, fbinfo[1] % 256)) goto done;
+ if(writex(fd, &x, fbinfo[1] % 256)) goto done;
+
done:
- if(ptr != MAP_FAILED) munmap(ptr, fbinfo[1]);
if(fb >= 0) close(fb);
close(fd);
}
-