Re: [PATCH v3 0/6] Add ARM support for VS2017

["Gao, Liming" <liming.gao@intel.com>]

Pete:
  Thanks for your update. I have no other comment on BaseTools and MdePkg part. Reviewed-by: Liming Gao <liming.gao@intel.com>

> -----Original Message-----
> From: Pete Batard [mailto:pete@akeo.ie]
> Sent: Friday, December 8, 2017 10:06 PM
> To: edk2-devel@lists.01.org
> Cc: Gao, Liming <liming.gao@intel.com>
> Subject: [PATCH v3 0/6] Add ARM support for VS2017
> 
> This v3 is the same as v2, except for the following comment added in
> tools_def for VS2017:
> # Building of XIP firmware images for ARM is not currently supported (only applications).
> # /FILEALIGN:4096 and other changes are needed for ARM firmware builds.
> 
> The following series adds ARM compilation support for the VS2017 toolchain.
> * PATCH 1 targets the disabling of VS Level 4 warnings. The disabled warnings
>   for ARM are now aligned with IA32 and X64.
> * PATCH 2 adds a NULL handler for the base stack check, since this is a GCC
>   functionality.
> * PATCH 3 updates MdePkg/Library/BaseLib so that the RVCT assembly sources
>   are also used for MSFT.
> * PATCH 4 adds the required compiler intrinsics replacements for division,
>   shift and memset/memcpy.
> * PATCH 5 adds variable argument handlers for print output. Note that this
>   is done without relying on any external headers, with the VA_ARG macro
>   having been reverse engineered from MSFT ARM assembly output.
> * PATCH 6 enables the selection of ARM in the conf templates.
> 
> With these patches, VS2017 toolchain users should be able to compile
> regular UEFI ARM applications using EDK2. Note that, unlike ARM64 support,
> ARM support does not require a specific update of Visual Studio 2017, as
> the ARM toolchain has been available from the very first release.
> 
> Additional notes:
> 
> We tested compiling and running the full UEFI Shell with this series, as
> well as a small set of applications and drivers, and found no issues.
> With an additional patch [1], it is also possible to use this proposal to
> compile a complete QEMU ARM firmware. As the patch shows, the changes that
> need to be applied to the EDK2 sources to achieve this are actually very
> minimal.
> 
> However, the generated firmware does not currently boot, possibly because
> of the following warnings being generated by the MS compiler:
> - ArmCpuDxe.dll : warning LNK4072: section count 118 exceeds max (96); image may not run
> - UiApp.dll : warning LNK4072: section count 113 exceeds max (96); image may not run
> 
> As far as I could see, the section count max is hardcoded so a workaround
> would be needed to address those.
> 
> Also, because the VS2017 ARM compiler forces a section alignment of 4096
> bytes (which in turn forces use to use /FILEALIGN:4096 as a linker option
> for the firmware generation), the generated firmware exceeds 2MB and we
> had to double its size to 4MB.
> 
> At this stage, since the goal of this series is to allow users to compile
> regular ARM UEFI applications using the VS2017 toolchain, I have non plans
> to spend more time on the QEMU firmware issues, especially as I suspect
> that reducing the firmware size back to 2 MB may not be achievable without
> Microsoft altering their compiler. I am however hopeful that ARM
> specialists can take this matter over eventually...
> 
> Regards,
> 
> /Pete
> 
> [1] https://github.com/pbatard/edk2/commit/c4ce41094a46f4f3dc7ccc64a90604813f037b13
> 
> Pete Batard (6):
>   MdePkg: Disable some Level 4 warnings for VS2017/ARM
>   MdePkg/Library/BaseStackCheckLib: Add Null handler for VS2017/ARM
>   MdePkg/Library/BaseLib: Enable VS2017/ARM builds
>   ArmPkg/Library/CompilerIntrinsicsLib: Enable VS2017/ARM builds
>   MdePkg/Include: Add VA list support for VS2017/ARM
>   BaseTools/Conf: Add VS2017/ARM support
> 
>  ArmPkg/Library/CompilerIntrinsicsLib/Arm/rtdiv.asm             | 255 ++++++++++++++++++++
>  ArmPkg/Library/CompilerIntrinsicsLib/Arm/rtsrsh.asm            |  45 ++++
>  ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf |  13 +-
>  ArmPkg/Library/CompilerIntrinsicsLib/memcpy_ms.c               |  34 +++
>  ArmPkg/Library/CompilerIntrinsicsLib/memset_ms.c               |  33 +++
>  BaseTools/Conf/build_rule.template                             |  31 ++-
>  BaseTools/Conf/tools_def.template                              |  31 +++
>  MdePkg/Include/Arm/ProcessorBind.h                             |  96 ++++++--
>  MdePkg/Include/Base.h                                          |  13 +
>  MdePkg/Library/BaseLib/Arm/CpuBreakpoint.asm                   |   5 +-
>  MdePkg/Library/BaseLib/BaseLib.inf                             |  16 +-
>  MdePkg/Library/BaseStackCheckLib/BaseStackCheckLib.inf         |   5 +-
>  MdePkg/Library/BaseStackCheckLib/BaseStackCheckNull.c          |  18 ++
>  13 files changed, 565 insertions(+), 30 deletions(-)
>  create mode 100644 ArmPkg/Library/CompilerIntrinsicsLib/Arm/rtdiv.asm
>  create mode 100644 ArmPkg/Library/CompilerIntrinsicsLib/Arm/rtsrsh.asm
>  create mode 100644 ArmPkg/Library/CompilerIntrinsicsLib/memcpy_ms.c
>  create mode 100644 ArmPkg/Library/CompilerIntrinsicsLib/memset_ms.c
>  create mode 100644 MdePkg/Library/BaseStackCheckLib/BaseStackCheckNull.c
> 
> --
> 2.9.3.windows.2