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-rw-r--r--Kbuild3
-rw-r--r--Makefile4
-rw-r--r--arch/arm/include/asm/global_data.h25
-rw-r--r--arch/arm/lib/eabi_compat.c15
-rw-r--r--arch/arm/lib/spl.c3
-rw-r--r--arch/arm/lib/vectors.S6
-rw-r--r--common/board_r.c2
-rw-r--r--doc/README.clang56
-rw-r--r--include/linux/kbuild.h6
-rw-r--r--scripts/Kbuild.include4
10 files changed, 107 insertions, 17 deletions
diff --git a/Kbuild b/Kbuild
index 6e1698c5bf..ef97787bf4 100644
--- a/Kbuild
+++ b/Kbuild
@@ -53,7 +53,8 @@ targets += arch/$(ARCH)/lib/asm-offsets.s
# Default sed regexp - multiline due to syntax constraints
define sed-y
- "/^->/{s:->#\(.*\):/* \1 */:; \
+ "s:[[:space:]]*\.ascii[[:space:]]*\"\(.*\)\":\1:; \
+ /^->/{s:->#\(.*\):/* \1 */:; \
s:^->\([^ ]*\) [\$$#]*\([-0-9]*\) \(.*\):#define \1 \2 /* \3 */:; \
s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
s:->::; p;}"
diff --git a/Makefile b/Makefile
index fdda3ec053..42263e4de2 100644
--- a/Makefile
+++ b/Makefile
@@ -197,8 +197,8 @@ CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
else if [ -x /bin/bash ]; then echo /bin/bash; \
else echo sh; fi ; fi)
-HOSTCC = gcc
-HOSTCXX = g++
+HOSTCC = cc
+HOSTCXX = c++
HOSTCFLAGS = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
HOSTCXXFLAGS = -O2
diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
index 63e4ad5a67..c69d0646f5 100644
--- a/arch/arm/include/asm/global_data.h
+++ b/arch/arm/include/asm/global_data.h
@@ -44,10 +44,35 @@ struct arch_global_data {
#include <asm-generic/global_data.h>
+#ifdef __clang__
+
+#define DECLARE_GLOBAL_DATA_PTR
+#define gd get_gd()
+
+static inline gd_t *get_gd(void)
+{
+ gd_t *gd_ptr;
+
+#ifdef CONFIG_ARM64
+ /*
+ * Make will already error that reserving x18 is not supported at the
+ * time of writing, clang: error: unknown argument: '-ffixed-x18'
+ */
+ __asm__ volatile("mov %0, x18\n" : "=r" (gd_ptr));
+#else
+ __asm__ volatile("mov %0, r9\n" : "=r" (gd_ptr));
+#endif
+
+ return gd_ptr;
+}
+
+#else
+
#ifdef CONFIG_ARM64
#define DECLARE_GLOBAL_DATA_PTR register volatile gd_t *gd asm ("x18")
#else
#define DECLARE_GLOBAL_DATA_PTR register volatile gd_t *gd asm ("r9")
#endif
+#endif
#endif /* __ASM_GBL_DATA_H */
diff --git a/arch/arm/lib/eabi_compat.c b/arch/arm/lib/eabi_compat.c
index 10d19333fc..a2cb06e49a 100644
--- a/arch/arm/lib/eabi_compat.c
+++ b/arch/arm/lib/eabi_compat.c
@@ -20,8 +20,19 @@ int raise (int signum)
/* Dummy function to avoid linker complaints */
void __aeabi_unwind_cpp_pr0(void)
{
-};
+}
void __aeabi_unwind_cpp_pr1(void)
{
-};
+}
+
+/* Copy memory like memcpy, but no return value required. */
+void __aeabi_memcpy(void *dest, const void *src, size_t n)
+{
+ (void) memcpy(dest, src, n);
+}
+
+void __aeabi_memset(void *dest, size_t n, int c)
+{
+ (void) memset(dest, c, n);
+}
diff --git a/arch/arm/lib/spl.c b/arch/arm/lib/spl.c
index dfcc596815..75ab546923 100644
--- a/arch/arm/lib/spl.c
+++ b/arch/arm/lib/spl.c
@@ -28,9 +28,6 @@ void __weak board_init_f(ulong dummy)
/* Clear the BSS. */
memset(__bss_start, 0, __bss_end - __bss_start);
- /* Set global data pointer. */
- gd = &gdata;
-
board_init_r(NULL, 0);
}
diff --git a/arch/arm/lib/vectors.S b/arch/arm/lib/vectors.S
index 493f3373f3..0cb87cee7f 100644
--- a/arch/arm/lib/vectors.S
+++ b/arch/arm/lib/vectors.S
@@ -45,12 +45,13 @@
*************************************************************************
*/
+_start:
+
#ifdef CONFIG_SYS_DV_NOR_BOOT_CFG
.word CONFIG_SYS_DV_NOR_BOOT_CFG
#endif
-_start:
- ldr pc, _reset
+ b reset
ldr pc, _undefined_instruction
ldr pc, _software_interrupt
ldr pc, _prefetch_abort
@@ -77,7 +78,6 @@ _start:
.globl _irq
.globl _fiq
-_reset: .word reset
_undefined_instruction: .word undefined_instruction
_software_interrupt: .word software_interrupt
_prefetch_abort: .word prefetch_abort
diff --git a/common/board_r.c b/common/board_r.c
index f9647e1358..551429c843 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -912,7 +912,7 @@ void board_init_r(gd_t *new_gd, ulong dest_addr)
int i;
#endif
-#ifndef CONFIG_X86
+#if !defined(CONFIG_X86) && !defined(CONFIG_ARM) && !defined(CONFIG_ARM64)
gd = new_gd;
#endif
diff --git a/doc/README.clang b/doc/README.clang
new file mode 100644
index 0000000000..9ad689f071
--- /dev/null
+++ b/doc/README.clang
@@ -0,0 +1,56 @@
+The biggest problem when trying to compile U-boot with clang is that
+almost all archs rely on storing gd in a global register and clang user
+manual states: "clang does not support global register variables; this
+is unlikely to be implemented soon because it requires additional LLVM
+backend support."
+
+Since version 3.4 the ARM backend can be instructed to leave r9 alone.
+Global registers themselves are not supported so some inline assembly is
+used to get its value. This does lead to larger code then strictly
+necessary, but at least works.
+
+NOTE: target compilation only work for _some_ ARM boards at the moment.
+Also Aarch64 is not supported: Most notably boards which aren't using
+the generic board will fail to compile, but since those are expected
+to be converted this will solve itself. Boards which reassign gd in c
+will also fail to compile, but there is in no strict reason to do so
+in the ARM world, since crt0.S takes care of this. These assignments
+can be avoided by changing the init calls but this is not in mainline yet.
+
+NOTE: without the -mllvm -arm-use-movt=0 flags u-boot will compile
+fine, but llvm might hardcode addresses in movw / movt pairs, which
+cannot be relocated and u-boot will fail at runtime.
+
+Debian (based)
+--------------
+Binary packages can be installed as usual, e.g.:
+sudo apt-get install clang
+
+To compile U-Boot with clang on linux without IAS use e.g.:
+export TRIPLET=arm-linux-gnueabi && export CROSS_COMPILE="$TRIPLET-"
+make HOSTCC=clang CC="clang -target $TRIPLET -mllvm -arm-use-movt=0 -no-integrated-as" rpi_b_defconfig
+make HOSTCC=clang CC="clang -target $TRIPLET -mllvm -arm-use-movt=0 -no-integrated-as" all V=1 -j8
+
+FreeBSD 11 (Current):
+--------------------
+Since llvm 3.4 is currently in the base system, the integrated as is
+incapable of building U-Boot. Therefore gas from devel/arm-eabi-binutils
+is used instead. It needs a symlinks to be picked up correctly though:
+
+ln -s /usr/local/bin/arm-eabi-as /usr/bin/arm-freebsd-eabi-as
+
+# The following commands compile U-Boot using the clang xdev toolchain.
+# NOTE: CROSS_COMPILE and target differ on purpose!
+export CROSS_COMPILE=arm-eabi-
+gmake CC="clang -target arm-freebsd-eabi --sysroot /usr/arm-freebsd -no-integrated-as -mllvm -arm-use-movt=0" rpi_b_defconfig
+gmake CC="clang -target arm-freebsd-eabi --sysroot /usr/arm-freebsd -no-integrated-as -mllvm -arm-use-movt=0" -j8
+
+Given that u-boot will default to gcc, above commands can be
+simplified with a simple wrapper script, listed below.
+
+/usr/local/bin/arm-eabi-gcc
+---
+#!/bin/sh
+
+exec clang -target arm-freebsd-eabi --sysroot /usr/arm-freebsd -no-integrated-as -mllvm -arm-use-movt=0 "$@"
+
diff --git a/include/linux/kbuild.h b/include/linux/kbuild.h
index ab7805a3b4..8a9f645e42 100644
--- a/include/linux/kbuild.h
+++ b/include/linux/kbuild.h
@@ -7,14 +7,14 @@
#define __LINUX_KBUILD_H
#define DEFINE(sym, val) \
- asm volatile("\n->" #sym " %0 " #val : : "i" (val))
+ asm volatile("\n.ascii \"->" #sym " %0 " #val "\"" : : "i" (val))
-#define BLANK() asm volatile("\n->" : : )
+#define BLANK() asm volatile("\n.ascii \"->\"" : : )
#define OFFSET(sym, str, mem) \
DEFINE(sym, offsetof(struct str, mem))
#define COMMENT(x) \
- asm volatile("\n->#" x)
+ asm volatile("\n.ascii \"->#" x "\"")
#endif
diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index c664e39be6..4c333599c1 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -113,12 +113,12 @@ as-instr = $(call try-run,\
# Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
cc-option = $(call try-run,\
- $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
+ $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",$(1),$(2))
# cc-option-yn
# Usage: flag := $(call cc-option-yn,-march=winchip-c6)
cc-option-yn = $(call try-run,\
- $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
+ $(CC) -Werror $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -x c /dev/null -o "$$TMP",y,n)
# cc-option-align
# Prefix align with either -falign or -malign
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