http://www.st.com/en/embedded-software/stm32cube-embedded-software.html

zip file: ~/Downloads/en.stm32cubel0.zip

this contains the lib, 
STM32Cube_FW_L0_V1.8.0/Drivers/STM32L0xx_HAL_Driver

however the lib requires a config file.
example is here:
STM32Cube_FW_L0_V1.8.0/Projects/STM32L011K4-Nucleo/Examples/GPIO/GPIO_IOToggle/Inc

startup code (.s files)
STM32Cube_FW_L0_V1.8.0/Drivers/CMSIS/Device/ST/STM32L0xx/Source/Templates/gcc

register definitions:
STM32Cube_FW_L0_V1.8.0/Drivers/CMSIS/Device/ST/STM32L0xx/Include

STM32L031xNyM
x: K=32 pins, F=20 pins
N: 4=16KB, 6=32KB
y: T=LQFP? 
M: temperature range

--> ld file for example here:
./Projects/STM32L031K6-Nucleo/Examples/SPI/SPI_FullDuplex_ComDMA/SW4STM32/STM32L031K6_NUCLEO/STM32L031K6Tx_FLASH.ld