[U-Boot] [PATCH 1/2] Allow board specific overwriting of library code

[Michael Roth]

Michael Roth schrieb:

> Because the whole weak-linking looks like it is somewhat broken or at
> least very difficult to get it correctly.

Small example:

In board/atmel/at91sam9261ek there is:

led.c:
	void red_LED_on(void)
	...
	void red_LED_off(void)
	...

Makefile:

	COBJS-y += led.o
	...
	OBJS    := $(addprefix $(obj),$(COBJS-y))
	...
	$(LIB): $(obj).depend $(OBJS) $(SOBJS)


And in lib_arm/board.c we have:

	void inline __red_LED_on (void) {}
	void inline red_LED_on (void) __attribute__((weak, alias("__red_LED_on")));
	void inline __red_LED_off(void) {}
	void inline red_LED_off(void)        __attribute__((weak, alias("__red_LED_off")));


But as you can see from u-boot.map, the result is not as expected:

	0x23f00340      0x35c lib_arm/libarm.a(board.o)
	0x23f00390                __red_LED_off
	...
	0x23f00390                red_LED_off
	...
	0x23f0038c                red_LED_on
	0x23f0038c                __red_LED_on


No single weak symbol from lib_arm/board.c get overridden from the
board specific led.c. Very annoying.


Michael Roth