compile-fc-batt: allow possible third field in source lines Battery tables maintained in the fc-battery-conf repository will now have a third field added, defining thresholds for the battery bars icon, and there will be a new utility to compile them into the new /etc/batterytab2 file read by the FC Tourmaline version of our FCHG driver. For backward compatibility with the original Magnetite version of FCHG, compile-fc-batt remains the tool for compiling the original /etc/batterytab file format, and it needs to ignore the newly added third field in battery table sources.

#include "ns16550.h"

@ extra serial I/O functions for loadagent binary operations

	.text
	.code	32
	.globl	serial_out_if_empty
serial_out_if_empty:
	ldr	r1, =uart_base
	ldr	r2, [r1]
	ldrb	r3, [r2, #NS16550_LSR]
	tst	r3, #NS16550_LSR_THRE
	strneb	r0, [r2, #NS16550_THR]
	bx	lr