ANSI C compatibility and support for AArch64

README.md

@@ -83,8 +83,8 @@ USE_LLVM = 1
 include uefi/Makefile
 ```
 The build environment configurator was created in a way that it can handle any number of architectures, however
-there's only `x86_64` crt0 implemented for now. There's an experimental `aarch64` crt0, which only compiles with
-the LLVM toolchain, GNU ld has some issues with it, saying "unsupported relocation" for ImageBase.
+only `x86_64` crt0 has been throughfully tested for now. There's an `aarch64` crt0 too, but since I don't have
+an ARM UEFI board, it hasn't been tested on real machine. Should work though.
 
 Notable Differences to POSIX libc
 ---------------------------------

examples/01_helloworld/Makefile

@@ -5,7 +5,7 @@ TARGET = helloworld.efi
 #define your sources here
 SRCS = $(wildcard *.c)
 # define your default compiler flags
-CFLAGS = -pedantic -Wall -Wextra -Werror --std=c11 -O2
+CFLAGS = -pedantic -Wall -Wextra -Werror --ansi -O2
 # define your default linker flags
 #LDFLAGS =
 # define your additional libraries here

uefi/Makefile

@@ -34,14 +34,20 @@ LIBS += -o $(TARGET).so -luefi -T uefi/elf_$(ARCH)_efi.lds
 ifneq ($(ARCH),$(MYARCH))
 CC = $(ARCH)-elf-gcc
 LD = $(ARCH)-elf-ld
+OBJCOPY ?= $(ARCH)-elf-objcopy
 else
 CC = gcc
 LD = ld
-endif
 OBJCOPY ?= objcopy
+endif
+ifeq ($(ARCH),aarch64)
+EFIARCH = pei-aarch64-little
+else
+EFIARCH = efi-app-$(ARCH)
+endif
 AR ?= ar
 else
-CFLAGS += --target=$(ARCH)-pc-win32-coff -Wno-builtin-requires-header -Wno-incompatible-library-redeclaration
+CFLAGS += --target=$(ARCH)-pc-win32-coff -Wno-builtin-requires-header -Wno-incompatible-library-redeclaration -Wno-long-long
 LDFLAGS += -subsystem:efi_application -nodefaultlib -dll -entry:uefi_init uefi/*.o
 LIBS = -out:$(TARGET)
 CC = clang
@@ -73,7 +79,7 @@ endif
 
 $(TARGET): $(TARGET).so
 ifeq ($(USE_LLVM),)
-	@$(OBJCOPY) -j .text -j .sdata -j .data -j .dynamic -j .dynsym  -j .rel -j .rela -j .rel.* -j .rela.* -j .reloc --target efi-app-$(ARCH) --subsystem=10 $^ $@
+	@$(OBJCOPY) -j .text -j .sdata -j .data -j .dynamic -j .dynsym  -j .rel -j .rela -j .rel.* -j .rela.* -j .reloc --target $(EFIARCH) --subsystem=10 $^ $@ || echo target: $(EFIARCH)
 	@rm $(TARGET).so
 endif
 

uefi/crt_aarch64.c

@@ -74,8 +74,7 @@ void bootstrap()
 #ifndef __clang__
     "	.globl _start\n"
     "_start:\n"
-    "	adr		x2, ImageBase\n"
-/*    "	mov		x2, xzr\n" */
+    "	ldr		x2, =ImageBase\n"
     "	adrp	x3, _DYNAMIC\n"
     "	add		x3, x3, #:lo12:_DYNAMIC\n"
     "	bl		uefi_init\n"
@@ -95,8 +94,10 @@ void bootstrap()
     "__chkstk:\n"
     "	ret\n"
 #endif
+    );
 
     /* setjmp and longjmp */
+    __asm__ __volatile__ (
     "	.p2align 3\n"
     "	.globl	setjmp\n"
     "setjmp:\n"
@@ -114,7 +115,8 @@ void bootstrap()
     "	stp	d14, d15, [x0, #160]\n"
     "	mov	w0, #0\n"
     "	ret\n"
-
+    );
+    __asm__ __volatile__ (
     "	.globl	longjmp\n"
     "longjmp:\n"
     "	ldp	x19, x20, [x0, #0]\n"

uefi/crt_x86_64.c

@@ -93,8 +93,10 @@ void bootstrap()
     "__chkstk:\n"
     "	ret\n"
 #endif
+    );
 
     /* setjmp and longjmp */
+    __asm__ __volatile__ (
     "	.globl	setjmp\n"
     "setjmp:\n"
     "	pop	%rsi\n"
@@ -109,7 +111,8 @@ void bootstrap()
     "	movq	%rsi,0x38(%rdi)\n"
     "	xor	%rax,%rax\n"
     "	ret\n"
-
+    );
+    __asm__ __volatile__ (
     "	.globl	longjmp\n"
     "longjmp:\n"
     "	movl	%esi, %eax\n"

uefi/uefi.h

@@ -51,6 +51,9 @@ typedef long long           int64_t;
 typedef unsigned long long  uint64_t;
 typedef unsigned long long  uintptr_t;
 #endif
+extern char c_assert1[sizeof(uint32_t) == 4  ? 1 : -1];
+extern char c_assert2[sizeof(uint64_t) == 8  ? 1 : -1];
+extern char c_assert3[sizeof(uintptr_t) == 8 ? 1 : -1];
 
 #ifndef NULL
 #define NULL ((void*)0)
@@ -901,7 +904,7 @@ typedef efi_status_t (EFIAPI *efi_file_set_info_t)(efi_file_handle_t *File, efi_
     void *Buffer);
 typedef efi_status_t (EFIAPI *efi_file_flush_t)(efi_file_handle_t *File);
 
-typedef struct efi_file_handle_s {
+struct efi_file_handle_s {
     uint64_t                Revision;
     efi_file_open_t         Open;
     efi_file_close_t        Close;
@@ -913,7 +916,7 @@ typedef struct efi_file_handle_s {
     efi_file_get_info_t     GetInfo;
     efi_file_set_info_t     SetInfo;
     efi_file_flush_t        Flush;
-} efi_file_handle_t;
+};
 
 /*** Shell Parameter Protocols ***/
 #ifndef EFI_SHELL_PARAMETERS_PROTOCOL_GUID
@@ -939,9 +942,9 @@ typedef struct {
     uintn_t         Argc;
     wchar_t         **RedirArgv;
     uintn_t         RedirArgc;
-    efi_handle_t StdIn;
-    efi_handle_t StdOut;
-    efi_handle_t StdErr;
+    efi_handle_t    StdIn;
+    efi_handle_t    StdOut;
+    efi_handle_t    StdErr;
 } efi_shell_interface_protocol_t;
 
 /*** Random Number Generator ***/