Re: [edk2-devel] [PATCH v1 1/1] BaseTools: Build ASL files before C files

["PierreGondois" <pierre.gondois@arm.com>]

Hello Ard,
I cannot find any documentation more than what the iASL compiler does with the '-tc' argument:
 -tc                 Create hex AML table in C (*.hex)

The '.hex' file looks like this:

#ifndef __ASL_SOURCE_FILE_HEX__
#define __ASL_SOURCE_FILE_HEX__

unsigned char ASL_SOURCE_FILE[] =
{
    0x53,0x53,0x44,0x54,0xAD,0x00,0x00,0x00,  /* 00000000    "SSDT...." */
    0x01,0xF8,0x41,0x52,0x4D,0x4C,0x54,0x44,  /* 00000008    "..ARMLTD" */
...
}

#endif __ASL_SOURCE_FILE_HEX__

I can make a python script to create a similar '.hex' file in case the iASL compiler changes its ouput. However this script would have to be included in Conf/build_rule.txt.

Regards,
Pierre

-----Original Message-----
From: Ard Biesheuvel <ard.biesheuvel@linaro.org> 
Sent: 18 December 2019 17:50
To: edk2-devel-groups-io <devel@edk2.groups.io>; Pierre Gondois <Pierre.Gondois@arm.com>
Cc: Feng, Bob C <bob.c.feng@intel.com>; Gao, Liming <liming.gao@intel.com>; Sami Mujawar <Sami.Mujawar@arm.com>; nd <nd@arm.com>
Subject: Re: [edk2-devel] [PATCH v1 1/1] BaseTools: Build ASL files before C files

On Wed, 30 Oct 2019 at 15:50, PierreGondois <pierre.gondois@arm.com> wrote:
>
> From: Pierre Gondois <pierre.gondois@arm.com>
>
> The '-tc' option of the Intel iASL compiler facilitates generation of 
> AML code in a C array. This AML code is output to a .hex file. The 
> .hex file can be included from a C source file, thereby allowing one 
> to run a fix-up code in C.
>
> For example, this technique can be used to patch the resource data 
> elements that describe the base address or interrupt number for a 
> device, before installing the ACPI table.
>
> To implement this feature two conditions need to be
> satisfied:
>  - The ASL and C files must be included in the sources
>    section of the same .inf file for the module.
>  - The ASL files are pre-processed and compiled before
>    the C files (so that the .hex file include dependency
>    is satisfied).
>
> This patch resolves the dependency by sorting the CODA_TARGET list for 
> the module being built and placing the .aml files at the very 
> beginning of the list.
>
> Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
> ---
>
> The changes can be seen at 
> https://github.com/PierreARM/edk2/commits/676_build_asl_first_v1
>

Hello Pierre,

I am not convinced it is a good idea to depend on what amounts to an implementation detail of the ASL compiler. Is the .hex format documented somewhere?


> Notes:
>     v1:
>     - Sort .aml files first in the CODA_TARGET to build      [Pierre]
>       them before other files.
>
>  BaseTools/Source/Python/AutoGen/ModuleAutoGen.py | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/BaseTools/Source/Python/AutoGen/ModuleAutoGen.py 
> b/BaseTools/Source/Python/AutoGen/ModuleAutoGen.py
> index 
> f0812b6887be6f9fbdb14003f2efff229633fb34..a59ed1d1952c23d0d3de83353a05
> 66fb8a7dab77 100755
> --- a/BaseTools/Source/Python/AutoGen/ModuleAutoGen.py
> +++ b/BaseTools/Source/Python/AutoGen/ModuleAutoGen.py
> @@ -2,6 +2,7 @@
>  # Create makefile for MS nmake and GNU make  #  # Copyright (c) 2019, 
> Intel Corporation. All rights reserved.<BR>
> +# Copyright (c) 2019, ARM Limited. All rights reserved.<BR>
>  # SPDX-License-Identifier: BSD-2-Clause-Patent  #  from __future__ 
> import absolute_import @@ -931,7 +932,14 @@ class 
> ModuleAutoGen(AutoGen):
>      @cached_property
>      def CodaTargetList(self):
>          self.Targets
> -        return self._FinalBuildTargetList
> +
> +        # To resolve dependencies on compiled ASL files (.aml files) in modules,
> +        # build them first by putting them as the first targets in the
> +        # CodaTargetList.
> +        OrderedList = list(self._FinalBuildTargetList)
> +        OrderedList.sort(key=lambda T: (T.Target.Ext.lower() != 
> + '.aml'))
> +
> +        return OrderedList
>
>      @cached_property
>      def FileTypes(self):
> --
> 'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)'
>
>
>
> 
>