[SOLVED] How to compile uefi application using gnu-efi?

How to compile uefi application using gnu-efi?

I tried to compile uefi code using gnu-efi. But I don't understand how to compile my uefi application code.

I get gnu-efi 3.0.2, decompress and type make && make install. I write hello world code:

#include <efi.h>
#include <efilib.h>

EFI_STATUS efi_main (EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable) {
    InitializeLib(ImageHandle, SystemTable);
    Print(L"Hello, world!\n");

    return EFI_SUCCESS;
}

My OS is Ubuntu 15.04.

Solution

Include the gnu-efi files
```
#include <efi.h> 
#include <efilib.h>
```
it looks like your includes where removed by SO
create the make file;

If you were building a "Hello, World" program for Linux in a Linux environment, you could compile it without a Makefile. Building the program in Linux for EFI, though, is essentially a cross-compilation operation. As such, it necessitates using unusual compilation and linker options, as well as a post-linking operation to convert the program into a form that the EFI will accept. Although you could type all the relevant commands by hand, a Makefile helps a lot.

ARCH            = $(shell uname -m | sed s,i[3456789]86,ia32,)

OBJS            = main.o
TARGET          = hello.efi

EFIINC          = /usr/include/efi
EFIINCS         = -I$(EFIINC) -I$(EFIINC)/$(ARCH) -I$(EFIINC)/protocol
LIB             = /usr/lib64
EFILIB          = /usr/lib64/gnuefi
EFI_CRT_OBJS    = $(EFILIB)/crt0-efi-$(ARCH).o
EFI_LDS         = $(EFILIB)/elf_$(ARCH)_efi.lds

CFLAGS          = $(EFIINCS) -fno-stack-protector -fpic \
          -fshort-wchar -mno-red-zone -Wall 
ifeq ($(ARCH),x86_64)
  CFLAGS += -DEFI_FUNCTION_WRAPPER
endif

LDFLAGS         = -nostdlib -znocombreloc -T $(EFI_LDS) -shared \
          -Bsymbolic -L $(EFILIB) -L $(LIB) $(EFI_CRT_OBJS) 

all: $(TARGET)

hello.so: $(OBJS)
    ld $(LDFLAGS) $(OBJS) -o $@ -lefi -lgnuefi

%.efi: %.so
    objcopy -j .text -j .sdata -j .data -j .dynamic \
        -j .dynsym  -j .rel -j .rela -j .reloc \
        --target=efi-app-$(ARCH) $^ $@

reference:

http://www.rodsbooks.com/efi-programming/hello.html