How to Infer a ROM's Contents from a file?

I'm trying to convert a Xilinx design onto a Cyclone V and am struggling with the Intel documentation on how to infer a ROM where its contents are provided by an external mif file​. Looking at the documentation this idea does not seem to be covered. (i.e. the examples all appear to generate the ROM contents within the hdl files)

Here is a snippet from the code I am trying to re-use:

impure function init_mem(mif_file_name : in string) return T_ROM_TYPE is

file mif_file : text open read_mode is mif_file_name;

variable mif_line : line;

variable temp_bv : std_logic_vector(G_DATA_WIDTH-1 downto 0);

variable temp_mem : T_ROM_TYPE;

begin

for i in T_ROM_TYPE'range loop

readline(mif_file, mif_line);

hread(mif_line, temp_bv);

temp_mem(i) := temp_bv;

end loop;

return temp_mem;

end function;

-- ROM array constant

constant rom : T_ROM_TYPE := init_mem(G_ROM_INIT_DATA);

begin

-------------------------------------------------------------------------------

-- ROM read access control

-------------------------------------------------------------------------------

rom_cotrol_proc : process (CLK)

variable address : integer range 0 to ((2**G_ADDR_WIDTH)-1);

begin

if CLK'event and CLK = '1' then

if IP_EN = '1' then

address := to_integer(unsigned(IP_ADDR((G_ADDR_WIDTH-1) downto 0)));

OP_DATA <= rom(address);

end if;

end if;

end process;