PP ram.link
LD rockbox.elf
/home/hillshum/rockbox/build/firmware/libfirmware.a(powermgmt.o): In function `battery_read_info':
powermgmt.c:(.text+0x34): undefined reference to `battery_adc_voltage'
/home/hillshum/rockbox/build/firmware/libfirmware.a(powermgmt.o): In function `power_thread':
powermgmt.c:(.text+0x7f0): undefined reference to `battery_adc_voltage'
collect2: ld returned 1 exit status
make: *** [/home/hillshum/rockbox/build/rockbox.elf] Error 1