Hi Jeroen,
Hi All,
Currently CONFIG_FB_ADDR can be set to specify the location of the frame buffer. Since Linux places the frame buffer at the end of the RAM, it is nice to place it at the same position so the u-boot to linux transition can be made flicker free, by preserving the frame buffer. However u-boot and it's heap prefer to locate themselves at the end of the RAM as well and there is nothing which prevents them to overlap.
While this can be set/calculated manually, it would be nicer if the relocation would never take place to the region occupied by the frame buffer. A simple way to do so is to locate u-boot before the frame buffer, like it is already done when the frame buffer address is not set.
Currently there are 2 boards using the CONFIG_FB_ADDR and CONFIG_LCD on arm (trats, mimc200). Would it cause any problem to relocate u-boot below the frame buffer on these boards?
Regards, Jeroen
proposed patch:
diff --git a/arch/arm/lib/board.c b/arch/arm/lib/board.c index e0cb635..4d0fc3c 100644 --- a/arch/arm/lib/board.c +++ b/arch/arm/lib/board.c @@ -371,9 +371,10 @@ void board_init_f(ulong bootflag) gd->fb_base = CONFIG_FB_ADDR; #else /* reserve memory for LCD display (always full pages) */
addr = lcd_setmem(addr);gd->fb_base = addr;
gd->fb_base = lcd_setmem(addr);#endif /* CONFIG_FB_ADDR */
/* always continue placement below the frame buffer to notoverlap */
Good idea. I will test it and let you know.