Let fbsplash display images even when a second buffer is active

If a previous application uses double buffering and makes the
second buffer visible, fbsplash's images (written to the first
buffer) otherwise won't be visible.

Signed-off-by: Dan Fandrich <dan@coneharvesters.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/miscutils/fbsplash.c b/miscutils/fbsplash.c
index 6b84563a3..150992343 100644
--- a/miscutils/fbsplash.c
+++ b/miscutils/fbsplash.c
@@ -83,11 +83,14 @@ static void fb_open(const char *strfb_device)
 
         // map the device in memory
         G.addr = mmap(NULL,
-                        G.scr_var.xres * G.scr_var.yres
+                        G.scr_var.xres * G.scr_var.yres_virtual
                         * BYTES_PER_PIXEL /*(G.scr_var.bits_per_pixel / 8)*/,
                         PROT_WRITE, MAP_SHARED, fbfd, 0);
         if (G.addr == MAP_FAILED)
                 bb_perror_msg_and_die("mmap");
+
+        // point to the start of the visible screen
+        G.addr += G.scr_var.yoffset * G.scr_fix.line_length + G.scr_var.xoffset * BYTES_PER_PIXEL;
         close(fbfd);
 }