GNU EFI header file

GNU-EFI is a very lightweight developing environment to create UEFI applications. The EDK2 is a large, complex environment with its own build system. GNU-EFI on the other hand is a set of libraries and headers for compiling UEFI applications with a system's native GCC.

efi.h: Contains other header files
    "eficompiler.h", "efidef.h", "efidevp.h", "efipciio.h", "efiprot.h", "eficon.h", "efiser.h", "efi_nii.h", "efipxebc.h", "efinet.h", "efiapi.h", "efifs.h", "efierr.h", "efiui.h", "efiip.h", "efiudp.h", "efitcp.h", "efipoint.h","efisetjmp.h"

efilib.h: 
     contain efi Use global variables in your application , EFI_GUID And common methods

extern EFI_SYSTEM_TABLE         *ST;
#define gST                      ST
extern EFI_BOOT_SERVICES        *BS;
#define gBS                      BS
extern EFI_RUNTIME_SERVICES     *RT;
#define gRT                      RT

Common methods ：
        InitializeLib, Print, WaitForSingleEvent, GetShellArgcArgv etc.
         And memory ( pool ) operation ,GUID operation , String manipulation , Arithmetic operations , lock , Input / Output , String to integer , Floating point conversion , event , Documents, etc.

efiapi.h:
     Define the main data structure and the method prototype in the structure ：

typedef struct _EFI_SYSTEM_TABLE {...} EFI_SYSTEM_TABLE;
typedef struct _EFI_BOOT_SERVICES {...} EFI_BOOT_SERVICES;
typedef struct  {...} EFI_RUNTIME_SERVICES;

eficompiler.h： Defined Microsoft Compiler related macro definitions
efidef.h： Defined gnu-efi Variable types used in ( Include ： Basic types ,GUID, Time ,IP/MAC Address, etc )
efidevp.h： Defined EFI Device path related structure in
efipciio.h： Defined EFI PCI Bus IO Related structures and methods
efiprot.h： Defined EFI Protocols supported in

eficon.h：
     Defined EFI in console Protocol and operation method

typedef struct _SIMPLE_TEXT_OUTPUT_INTERFACE {...} SIMPLE_TEXT_OUTPUT_INTERFACE, EFI_SIMPLE_TEXT_OUT_PROTOCOL;
typedef struct _SIMPLE_INPUT_INTERFACE {...} SIMPLE_INPUT_INTERFACE, EFI_SIMPLE_TEXT_IN_PROTOCOL;

efiser.h： Defined EFI Middle serial port (serial) Protocol and operation method
efi_nii.h： Defined EFI Network interface identification protocol in     
efipxebc.h： Defined EFI in PXE Base Code agreement
efinet.h： Defined EFI Basic network protocol
efifs.h： Defined EFI Basic file system structure in
efierr.h： Defined EFI Error code in
efiui.h： Defined EFI structure UI The agreement
efiip.h： Defined EFI Use in IPV4/6 Structure and method of
efiudp.h： Defined EFI Use in IPV4/6 UDP Structure and method of protocol
efitcp.h： Defined EFI Use in IPV4/6 TCP Structure and method of protocol
efipoint.h： Defined EFI in SIMPLE POINTER agreement
efisetjmp.h： Defined setjmp,longjmp Two jump methods