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 vbendeb@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 sr@denx.de Cc: Simon Glass sjg@chromium.org Cc: Bin Meng bmeng.cn@gmail.com --- v2: - Added coreboot git repository link to commit message
arch/x86/config.mk | 3 -- arch/x86/lib/Makefile | 2 +- arch/x86/lib/div64.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++ arch/x86/lib/gcc.c | 29 ------------- 4 files changed, 114 insertions(+), 33 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 $(IS_32BIT),elf_i386,elf_x86_64)
-LDFLAGS_FINAL += --wrap=__divdi3 --wrap=__udivdi3 -LDFLAGS_FINAL += --wrap=__moddi3 --wrap=__umoddi3 - # This is used in the top-level Makefile which does not include # PLATFORM_LDFLAGS LDFLAGS_EFI_PAYLOAD := -Bsymbolic -Bsymbolic-functions -shared --no-undefined diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index fe00d7573f..d9b23f5cc4 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -18,7 +18,7 @@ obj-$(CONFIG_SEABIOS) += coreboot_table.o obj-y += early_cmos.o obj-$(CONFIG_EFI) += efi/ obj-y += e820.o -obj-y += gcc.o +obj-y += div64.o obj-y += init_helpers.o obj-y += interrupts.o obj-y += lpc-uclass.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