This patch removes the inclusion of the libgcc math functions and
replaces them by functions coded in C, taken from the coreboot
project. This makes U-Boot building more independent from the toolchain
installed / available on the build system.
The code taken from coreboot is authored from Vadim Bendebury
<vben...@chromium.org> on 2014-11-28 and committed with commit
ID e63990ef [libpayload: provide basic 64bit division implementation]
(coreboot git repository located here [1]).
I modified the code so that its checkpatch clean without any
functional changes.
[1] git://github.com/coreboot/coreboot.git
Signed-off-by: Stefan Roese <s...@denx.de>
Cc: Simon Glass <s...@chromium.org>
Cc: Bin Meng <bmeng...@gmail.com>
---
v3:
- Completely get rid of all libgcc references in arch/x86/lib/Makefile,
also for the standalone applications
v2:
- Added coreboot git repository link to commit message
arch/x86/config.mk | 3 --
arch/x86/lib/Makefile | 8 +---
arch/x86/lib/div64.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++
arch/x86/lib/gcc.c | 29 -------------
4 files changed, 114 insertions(+), 39 deletions(-)
create mode 100644 arch/x86/lib/div64.c
delete mode 100644 arch/x86/lib/gcc.c
diff --git a/arch/x86/config.mk b/arch/x86/config.mk
index 8835dcf36f..472ada5490 100644
--- a/arch/x86/config.mk
+++ b/arch/x86/config.mk
@@ -34,9 +34,6 @@ PLATFORM_RELFLAGS += -ffunction-sections -fvisibility=hidden
PLATFORM_LDFLAGS += -Bsymbolic -Bsymbolic-functions
PLATFORM_LDFLAGS += -m $(if $(IS_32BIT),elf_i386,elf_x86_64)
-LDFLAGS_FINAL += --wrap=__divdi3 --wrap=__udivdi3
-LDFLAGS_FINAL += --wrap=__moddi3 --wrap=__umoddi3
-
# This is used in the top-level Makefile which does not include
# PLATFORM_LDFLAGS
LDFLAGS_EFI_PAYLOAD := -Bsymbolic -Bsymbolic-functions -shared --no-undefined
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index fe00d7573f..7d729ea0f7 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -18,7 +18,6 @@ obj-$(CONFIG_SEABIOS) += coreboot_table.o
obj-y += early_cmos.o
obj-$(CONFIG_EFI) += efi/
obj-y += e820.o
-obj-y += gcc.o
obj-y += init_helpers.o
obj-y += interrupts.o
obj-y += lpc-uclass.o
@@ -49,12 +48,7 @@ endif
obj-$(CONFIG_HAVE_FSP) += fsp/
obj-$(CONFIG_SPL_BUILD) += spl.o
-extra-$(CONFIG_USE_PRIVATE_LIBGCC) += lib.a
-
-NORMAL_LIBGCC = $(shell $(CC) $(PLATFORM_CPPFLAGS) -print-libgcc-file-name)
-OBJCOPYFLAGS := --prefix-symbols=__normal_
-$(obj)/lib.a: $(NORMAL_LIBGCC) FORCE
- $(call if_changed,objcopy)
+lib-$(CONFIG_USE_PRIVATE_LIBGCC) += div64.o
ifeq ($(CONFIG_$(SPL_)X86_64),)
obj-$(CONFIG_EFI_APP) += crt0_ia32_efi.o reloc_ia32_efi.o
diff --git a/arch/x86/lib/div64.c b/arch/x86/lib/div64.c
new file mode 100644
index 0000000000..4efed74037
--- /dev/null
+++ b/arch/x86/lib/div64.c
@@ -0,0 +1,113 @@
+/*
+ * This file is copied from the coreboot repository as part of
+ * the libpayload project:
+ *
+ * Copyright 2014 Google Inc.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <common.h>
+
+union overlay64 {
+ u64 longw;
+ struct {
+ u32 lower;
+ u32 higher;
+ } words;
+};
+
+u64 __ashldi3(u64 num, unsigned int shift)
+{
+ union overlay64 output;
+
+ output.longw = num;
+ if (shift >= 32) {
+ output.words.higher = output.words.lower << (shift - 32);
+ output.words.lower = 0;
+ } else {
+ if (!shift)
+ return num;
+ output.words.higher = (output.words.higher << shift) |
+ (output.words.lower >> (32 - shift));
+ output.words.lower = output.words.lower << shift;
+ }
+ return output.longw;
+}
+
+u64 __lshrdi3(u64 num, unsigned int shift)
+{
+ union overlay64 output;
+
+ output.longw = num;
+ if (shift >= 32) {
+ output.words.lower = output.words.higher >> (shift - 32);
+ output.words.higher = 0;
+ } else {
+ if (!shift)
+ return num;
+ output.words.lower = output.words.lower >> shift |
+ (output.words.higher << (32 - shift));
+ output.words.higher = output.words.higher >> shift;
+ }
+ return output.longw;
+}
+
+#define MAX_32BIT_UINT ((((u64)1) << 32) - 1)
+
+static u64 _64bit_divide(u64 dividend, u64 divider, u64 *rem_p)
+{
+ u64 result = 0;
+
+ /*
+ * If divider is zero - let the rest of the system care about the
+ * exception.
+ */
+ if (!divider)
+ return 1 / (u32)divider;
+
+ /* As an optimization, let's not use 64 bit division unless we must. */
+ if (dividend <= MAX_32BIT_UINT) {
+ if (divider > MAX_32BIT_UINT) {
+ result = 0;
+ if (rem_p)
+ *rem_p = divider;
+ } else {
+ result = (u32)dividend / (u32)divider;
+ if (rem_p)
+ *rem_p = (u32)dividend % (u32)divider;
+ }
+ return result;
+ }
+
+ while (divider <= dividend) {
+ u64 locald = divider;
+ u64 limit = __lshrdi3(dividend, 1);
+ int shifts = 0;
+
+ while (locald <= limit) {
+ shifts++;
+ locald = locald + locald;
+ }
+ result |= __ashldi3(1, shifts);
+ dividend -= locald;
+ }
+
+ if (rem_p)
+ *rem_p = dividend;
+
+ return result;
+}
+
+u64 __udivdi3(u64 num, u64 den)
+{
+ return _64bit_divide(num, den, NULL);
+}
+
+u64 __umoddi3(u64 num, u64 den)
+{
+ u64 v = 0;
+
+ _64bit_divide(num, den, &v);
+ return v;
+}
diff --git a/arch/x86/lib/gcc.c b/arch/x86/lib/gcc.c
deleted file mode 100644
index 3c70d790d4..0000000000
--- a/arch/x86/lib/gcc.c
+++ /dev/null
@@ -1,29 +0,0 @@
-/*
- * This file is part of the coreboot project.
- *
- * Copyright (C) 2009 coresystems GmbH
- *
- * SPDX-License-Identifier: GPL-2.0
- */
-
-#ifdef __GNUC__
-
-/*
- * GCC's libgcc handling is quite broken. While the libgcc functions
- * are always regparm(0) the code that calls them uses whatever the
- * compiler call specifies. Therefore we need a wrapper around those
- * functions. See gcc bug PR41055 for more information.
- */
-#define WRAP_LIBGCC_CALL(type, name) \
- type __normal_##name(type a, type b) __attribute__((regparm(0))); \
- type __wrap_##name(type a, type b); \
- type __attribute__((no_instrument_function)) \
- __wrap_##name(type a, type b) \
- { return __normal_##name(a, b); }
-
-WRAP_LIBGCC_CALL(long long, __divdi3)
-WRAP_LIBGCC_CALL(unsigned long long, __udivdi3)
-WRAP_LIBGCC_CALL(long long, __moddi3)
-WRAP_LIBGCC_CALL(unsigned long long, __umoddi3)
-
-#endif
--
2.15.0
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