On 11/15/2016 08:43 AM, Moore, Robert wrote:
The design for all of this is as follows:
1) OS-dependent includes
2) Compiler-specific includes
3) acenv.h is the master file that pulls in the correct headers (one compiler, and one
Sure, that's understood from the current structure. The issue is #3 -- there
is no OS, in the sense of a run-time environment, so that assumption is
incorrect in this case. All we know is that we're compiling the kernel and it
needs to be able to run in complete isolation.
So, I think I see a couple of possible solutions for you:
1) If you are using GCC, the __GNUC__ symbol should already be defined.
Right, which is what this patch is relying on.
2) If "aclinux.h" works for you, we can either add a
conditional case that would apply to your environment, or:
I'm confused; I thought that was what this patch was doing. What is
being suggested instead?
2a) You could define _LINUX in your gcc invocations.
This option might force changes in the kernel build which is otherwise not
affected; this is only an issue with drivers/acpi/acpica/*. It may also
cause ACPICA to build incorrectly for other OSs, but I'll have to look at
that. Off hand, it seems like this would cause more problems with acenv.h.
Because ACPICA supports many different environments, we don't want to have a
"default" case which in a sense would only be an attempt to guess what the user
intended. We want to have a clear error that tells the user that something important needs
to be done before the code can be compiled.
Understood, which is why I left the #error case; the intent is only to have
a default when compiling Linux for bare-metal environments using GCC. Perhaps
this is just a Linux-only modification...
> -----Original Message-----
> From: Al Stone [mailto:firstname.lastname@example.org]
> Sent: Monday, November 14, 2016 3:09 PM
> To: linux-acpi(a)vger.kernel.org; devel(a)acpica.org; linux-
> Cc: Al Stone <ahs3(a)redhat.com>; Rafael J . Wysocki <rjw(a)rjwysocki.net>;
> Len Brown <lenb(a)kernel.org>; Moore, Robert <robert.moore(a)intel.com>;
> Zheng, Lv <lv.zheng(a)intel.com>
> Subject: [PATCH] ACPI: allow compilation with bare metal compilers
> The ACPICA subsystem of the ACPI driver sets up a compilation
> environment for itself, adding in multiple typedefs unique to ACPICA
> that depend on where ACPICA will be used.
> The vast majority of such environments (Linux, QNX, ...) have an
> environment defined by the acenv.h header file. When using a Linaro
> compiler  specifically built to be used in an embedded environment
> with perhaps a kernel and an init process as the only things running,
> there is no environment defined for ACPICA so the typedefs it needs are
> not set up, causing compilation to fail badly unless ACPI is completely
> Since ACPI is enabled in the default config for the kernel, the
> compilation failure is fairly obvious.
> This may not be the optimal solution, but add in to the ACPI header file
> include/acpi/platform/acenv.h a default so that if GCC is being used,
> and all else fails, assume that we are going to be in a Linux-like
> environment and re-use the environment definition for Linux. This
> allows us to build a kernel using this compiler  with or without
> Signed-off-by: Al Stone <ahs3(a)redhat.com>
> Cc: Rafael J. Wysocki <rjw(a)rjwysocki.net>
> Cc: Len Brown <lenb(a)kernel.org>
> Cc: Robert Moore <robert.moore(a)intel.com>
> Cc: Lv Zheng <lv.zheng(a)intel.com>
> include/acpi/platform/acenv.h | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
> diff --git a/include/acpi/platform/acenv.h
> b/include/acpi/platform/acenv.h index 34cce72..cdd1cd6 100644
> --- a/include/acpi/platform/acenv.h
> +++ b/include/acpi/platform/acenv.h
> @@ -234,6 +234,21 @@
> #elif defined(_AED_EFI) || defined(_GNU_EFI) || defined(_EDK2_EFI)
> #include "acefi.h"
> + * Up to this point, we've been looking for specific environments. In
> + * some cases, there is no environment, and we're just working on bare
> + * metal. However, since we're compiling the Linux kernel, let's just
> + * pretend we're in a Linux environment.
> + */
> +#elif defined(__GNUC__) && !defined(__INTEL_COMPILER) #if
> +!defined(_LINUX) #define _LINUX #endif #if !defined(__linux__) #define
> +__linux__ #endif #include <acpi/platform/aclinux.h>
> /* Unknown environment */
Red Hat, Inc.