title: "fatal error: asm/early_ioremap.h: No such file or directory"
body: <p>why am I getting  "fatal error: asm/early_ioremap.h: No such file or directory"  while building simple hello world kernel driver for x86_64 with Linux 4.4.15 libraries using gcc-4.8.5? gcc is searching for asm/early_ioremap.h  which is not available in Linux 4.4.15.
  any idea how can i fix this? </p>
  
  <pre><code>/opt/gcc-4.8.5-glibc-2.21-p8/x86_64-linux-gnu/bin/x86_64-linux-gnu-gcc -M -MP -MT '/home/obj/src/kernel/hello_world/hello.o' -MT '/home/obj/src/kernel/hello_world/hello.d' -MT 'hello.E' -MT 'hello.S' -I/home/src/kernel/hello_world -I/home/obj/src/kernel/linux-4.4.15/include -I/home/src/inc -I/home/obj/src/kernel/linux-4.4.15/arch/x86/include -D__KERNEL__ -DMODULE -DPACKET_LEAK_TRACING -DSIZEOF_CPU_REGISTER=8 -DNUM_DEV_CF=0 -DNUM_DEV_USB=0  -mtune=nocona  -march=nocona  -m64 -pipe  -std=gnu89 -g -nostdinc  -isystem /opt/gcc-4.8.5-glibc-2.21-p8/x86_64-linux-gnu/lib/gcc/x86_64-linux-gnu/4.8.5/include -O2   -fno-strict-aliasing -fno-common -ffreestanding -Wall -Wstrict-prototypes -Wno-trigraphs -Wmissing-format-attribute -Wdisabled-optimization -Wwrite-strings -Wimplicit-int -Wmissing-braces -Wmissing-noreturn  -Wundef -Wmissing-field-initializers -Wmissing-declarations -Wmissing-prototypes -Wno-unused-parameter -Winline -mcmodel=kernel  -fno-omit-frame-pointer  -fno-stack-protector -mno-red-zone -fno-asynchronous-unwind-tables -imacros generated/autoconf.h   hello.c  -I/home/obj/src/kernel/linux-4.4.15/include/uapi/  -I/home/obj/src/kernel/linux-4.4.15/arch/x86/include/uapi/  
  In file included from /home/obj/src/kernel/linux-4.4.15/arch/x86/include/asm/realmode.h:5:0,
                   from /home/obj/src/kernel/linux-4.4.15/arch/x86/include/asm/acpi.h:33,
                   from /home/obj/src/kernel/linux-4.4.15/arch/x86/include/asm/fixmap.h:19,
                   from /home/obj/src/kernel/linux-4.4.15/arch/x86/include/asm/apic.h:12,
                   from /home/obj/src/kernel/linux-4.4.15/arch/x86/include/asm/smp.h:12,
                   from /home/obj/src/kernel/linux-4.4.15/arch/x86/include/asm/mmzone_64.h:10,
                   from /home/obj/src/kernel/linux-4.4.15/arch/x86/include/asm/mmzone.h:4,
                   from /home/obj/src/kernel/linux-4.4.15/include/linux/mmzone.h:856,
                   from /home/obj/src/kernel/linux-4.4.15/include/linux/gfp.h:5,
                   from /home/obj/src/kernel/linux-4.4.15/include/linux/kmod.h:22,
                   from /home/obj/src/kernel/linux-4.4.15/include/linux/module.h:13,
                   from hello.c:1:
  /home/obj/src/kernel/linux-4.4.15/arch/x86/include/asm/io.h:43:31: fatal error: asm/early_ioremap.h: No such file or directory
   #include &lt;asm/early_ioremap.h&gt;
                                 ^
  compilation terminated.
  </code></pre>