Re: [PATCH 2/3] ArmPlatformPkg: PrePeiCore: write early hello message to the serial port

["Sami Mujawar" <sami.mujawar@arm.com>]

[-- Attachment #1: Type: text/plain, Size: 6796 bytes --]

Hi Oliver,

Both your and Rebecca’s patches are using SerialPortWrite() which should work regardless of the debug print level and for release builds as well.
Rebecca’s patch additionally initialises the serial port which is required if the UART has not been setup by any previous firmware.
I believe Qemu might handoff with the UART initialised, therefore you might not see the difference. However, this would be required for some hardware platforms.

I do not have a setup with Qemu ready to try. Is it possible for you to apply Rebecca’s patch and check, please?
Alternatively, I will prepare a setup tomorrow to confirm.

Regards,

Sami Mujawar

From: Oliver Steffen <osteffen@redhat.com>
Date: Tuesday, 26 July 2022 at 16:50
To: Sami Mujawar <Sami.Mujawar@arm.com>
Cc: "devel@edk2.groups.io" <devel@edk2.groups.io>, Rebecca Cran <rebecca@bsdio.com>, "quic_rcran@quicinc.com" <quic_rcran@quicinc.com>, Ard Biesheuvel <ardb+tianocore@kernel.org>, Chasel Chiu <chasel.chiu@intel.com>, Gerd Hoffmann <kraxel@redhat.com>, Leif Lindholm <quic_llindhol@quicinc.com>, Nate DeSimone <nathaniel.l.desimone@intel.com>, Star Zeng <star.zeng@intel.com>, Andrew Fish <afish@apple.com>, Laszlo Ersek <lersek@redhat.com>
Subject: Re: [PATCH 2/3] ArmPlatformPkg: PrePeiCore: write early hello message to the serial port

Hi Sami,

Thank you for pointing to that patch. It pretty much does the same thing
and I would be OK with using it instead of these changes here. Except
that the message only shows up in debug mode and seems to depend on the
debug mask. It would be nice if it would show up all the time.

We are building ArmVirt in debug, but with
DEBUG_PRINT_ERROR_LEVEL=0x80000000, aka a "silent" debug build, and need
the message there too.

What was proposed in this series prints the message independently of the
debug mask.

Regards,
 Oliver

On Tue, Jul 26, 2022 at 12:42 PM Sami Mujawar <Sami.Mujawar@arm.com<mailto:Sami.Mujawar@arm.com>> wrote:
Hi Oliver,

There is a patch for review at https://edk2.groups.io/g/devel/message/88884 which prints the firmware version string. I believe with Ard's comments addressed that patch can be merged.
Would that patch solve your purpose to print an early message for debug purpose?

Regards,

Sami Mujawar

On 26/07/2022, 08:29, "Oliver Steffen" <osteffen@redhat.com<mailto:osteffen@redhat.com>> wrote:

    From: Laszlo Ersek <lersek@redhat.com<mailto:lersek@redhat.com>>

    Print the early hello message to the serial port.

    The FixedPcdGetSize() macro expands to an integer constant, therefore an
    optimizing compiler can eliminate the new code, if the platform DSC
    doesn't override the empty string (size=1) default of
    PcdEarlyHelloMessage.

    Signed-off-by: Laszlo Ersek <lersek@redhat.com<mailto:lersek@redhat.com>>
    Signed-off-by: Oliver Steffen <osteffen@redhat.com<mailto:osteffen@redhat.com>>
    ---
     ArmPlatformPkg/PrePeiCore/PrePeiCoreMPCore.inf  | 2 ++
     ArmPlatformPkg/PrePeiCore/PrePeiCoreUniCore.inf | 2 ++
     ArmPlatformPkg/PrePeiCore/PrePeiCore.h          | 1 +
     ArmPlatformPkg/PrePeiCore/MainMPCore.c          | 7 +++++++
     ArmPlatformPkg/PrePeiCore/MainUniCore.c         | 7 +++++++
     5 files changed, 19 insertions(+)

    diff --git a/ArmPlatformPkg/PrePeiCore/PrePeiCoreMPCore.inf b/ArmPlatformPkg/PrePeiCore/PrePeiCoreMPCore.inf
    index a5b4722459d1..ea7b220bc831 100644
    --- a/ArmPlatformPkg/PrePeiCore/PrePeiCoreMPCore.inf
    +++ b/ArmPlatformPkg/PrePeiCore/PrePeiCoreMPCore.inf
    @@ -66,6 +66,8 @@ [FixedPcd]
       gArmPlatformTokenSpaceGuid.PcdCPUCorePrimaryStackSize
       gArmPlatformTokenSpaceGuid.PcdCPUCoreSecondaryStackSize

    +  gArmPlatformTokenSpaceGuid.PcdEarlyHelloMessage
    +
       gArmTokenSpaceGuid.PcdGicDistributorBase
       gArmTokenSpaceGuid.PcdGicInterruptInterfaceBase
       gArmTokenSpaceGuid.PcdGicSgiIntId
    diff --git a/ArmPlatformPkg/PrePeiCore/PrePeiCoreUniCore.inf b/ArmPlatformPkg/PrePeiCore/PrePeiCoreUniCore.inf
    index 466a2b01c384..29fb8737cb2f 100644
    --- a/ArmPlatformPkg/PrePeiCore/PrePeiCoreUniCore.inf
    +++ b/ArmPlatformPkg/PrePeiCore/PrePeiCoreUniCore.inf
    @@ -64,4 +64,6 @@ [FixedPcd]
       gArmPlatformTokenSpaceGuid.PcdCPUCorePrimaryStackSize
       gArmPlatformTokenSpaceGuid.PcdCPUCoreSecondaryStackSize

    +  gArmPlatformTokenSpaceGuid.PcdEarlyHelloMessage
    +
       gEfiMdeModulePkgTokenSpaceGuid.PcdInitValueInTempStack
    diff --git a/ArmPlatformPkg/PrePeiCore/PrePeiCore.h b/ArmPlatformPkg/PrePeiCore/PrePeiCore.h
    index 0345dd7bdd2a..ae8302becda2 100644
    --- a/ArmPlatformPkg/PrePeiCore/PrePeiCore.h
    +++ b/ArmPlatformPkg/PrePeiCore/PrePeiCore.h
    @@ -16,6 +16,7 @@
     #include <Library/DebugLib.h>
     #include <Library/IoLib.h>
     #include <Library/PcdLib.h>
    +#include <Library/SerialPortLib.h>

     #include <PiPei.h>
     #include <Ppi/TemporaryRamSupport.h>
    diff --git a/ArmPlatformPkg/PrePeiCore/MainMPCore.c b/ArmPlatformPkg/PrePeiCore/MainMPCore.c
    index b5d0d3a6442f..21c9d5f6da8f 100644
    --- a/ArmPlatformPkg/PrePeiCore/MainMPCore.c
    +++ b/ArmPlatformPkg/PrePeiCore/MainMPCore.c
    @@ -116,6 +116,13 @@ PrimaryMain (
       UINTN                   TemporaryRamBase;
       UINTN                   TemporaryRamSize;

    +  if (FixedPcdGetSize (PcdEarlyHelloMessage) > 1) {
    +    SerialPortWrite (
    +      FixedPcdGetPtr (PcdEarlyHelloMessage),
    +      FixedPcdGetSize (PcdEarlyHelloMessage) - 1
    +      );
    +  }
    +
       CreatePpiList (&PpiListSize, &PpiList);

       // Enable the GIC Distributor
    diff --git a/ArmPlatformPkg/PrePeiCore/MainUniCore.c b/ArmPlatformPkg/PrePeiCore/MainUniCore.c
    index 1c2580eb923b..37560540e14f 100644
    --- a/ArmPlatformPkg/PrePeiCore/MainUniCore.c
    +++ b/ArmPlatformPkg/PrePeiCore/MainUniCore.c
    @@ -29,6 +29,13 @@ PrimaryMain (
       UINTN                   TemporaryRamBase;
       UINTN                   TemporaryRamSize;

    +  if (FixedPcdGetSize (PcdEarlyHelloMessage) > 1) {
    +    SerialPortWrite (
    +      FixedPcdGetPtr (PcdEarlyHelloMessage),
    +      FixedPcdGetSize (PcdEarlyHelloMessage) - 1
    +      );
    +  }
    +
       CreatePpiList (&PpiListSize, &PpiList);

       // Adjust the Temporary Ram as the new Ppi List (Common + Platform Ppi Lists) is created at
    --
    2.37.1


IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

[-- Attachment #2: Type: text/html, Size: 12391 bytes --]