All the code in early_serial_console.c gets compiled out if
!CONFIG_EARLY_PRINTK, but early_serial_console.o itself still gets
compiled in.  Eliminate it from the compile entirely in that case.

This does not change the generated code at all, in either case.
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>

Removes early_serial_console.c code if we don't have the config option that
enables it (EARLY_PRINTK). When disabling this code, make early_serial_base a
constant 0 to allow the compiler to optimize away the code that checks for
early_serial_base.
Signed-off-by: NJoe Millenbach <jmillenbach@gmail.com>
Link: http://lkml.kernel.org/r/1342746282-28497-7-git-send-email-jmillenbach@gmail.comSigned-off-by: NGokul Caushik <caushik1@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

This enables the decompressor output to be seen on the serial console.
Most of the code is shared with the regular boot code.

We could add printf to the decompressor if needed, but currently there
is no sufficiently compelling user.

-v2: define BOOT_BOOT_H to avoid include boot.h
-v3: early_serial_base need to be static in misc.c ?
-v4: create seperate string.c printf.c cmdline.c early_serial_console.c
     after hpa's patch that allow global variables in compressed/misc stage
-v5: remove printf.c related
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>