Re: [U-Boot] [PATCH v3] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones

[Ferry Toth]

Op Wed, 29 Nov 2017 16:23:31 +0100, schreef Stefan Roese:

> 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.

Thanks Stefan,

Great work, I'll try to test that soon.

BTW I eventually have been able to work around the problem in Yocto. The 
work around involved creating a seperate .conf file for u-boot which 
includes multilib support. I couldn't add multilib support to my 
rootfs .conf file because that broke building the sdk. Of course the 
effect is to build a complete seperate target infrastructure (x86_64 + 
ml) just to build one binary. 

This patch will save people a lot of grief I'm sure.
 
> The code taken from coreboot is authored from Vadim Bendebury
>  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 
> Cc: Simon Glass 
> Cc: Bin Meng 
> ---
> 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 00..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 
> +
> +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 = 

Re: [U-Boot] [PATCH v3] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones

[Bin Meng]

On Thu, Nov 30, 2017 at 1:31 PM, Bin Meng  wrote:
> On Wed, Nov 29, 2017 at 11:23 PM, Stefan Roese  wrote:
>> 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
>>  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 
>> Cc: Simon Glass 
>> Cc: Bin Meng 
>> ---
>> 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
>>
>
> Reviewed-by: Bin Meng 
> Tested-by: Bin Meng 

applied to u-boot-x86, thanks!
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Re: [U-Boot] [PATCH v3] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones

[Bin Meng]

On Wed, Nov 29, 2017 at 11:23 PM, Stefan Roese  wrote:
> 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
>  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 
> Cc: Simon Glass 
> Cc: Bin Meng 
> ---
> 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
>

Reviewed-by: Bin Meng 
Tested-by: Bin Meng 
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[U-Boot] [PATCH v3] x86: lib: Implement standalone __udivdi3 etc instead of libgcc ones

[Stefan Roese]

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
 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 
Cc: Simon Glass 
Cc: Bin Meng 
---
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 00..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 
+
+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