From: Laszlo Ersek <lersek@redhat.com>
To: Jordan Justen <jordan.l.justen@intel.com>, edk2-devel@lists.01.org
Subject: Re: [PATCH 00/12] OvmfPkg: Enable variable access in PEI
Date: Mon, 27 Mar 2017 20:03:42 +0200 [thread overview]
Message-ID: <a12bbf61-3f55-2fda-b855-58aeb99a4f42@redhat.com> (raw)
In-Reply-To: <20170327080544.24748-1-jordan.l.justen@intel.com>
On 03/27/17 10:05, Jordan Justen wrote:
> web: https://github.com/jljusten/edk2/tree/pei-vars-v1
>
> git: https://github.com/jljusten/edk2.git pei-vars-v1
>
> This series moves flash detection into PEI to allow the PEI variable
> access drivers to run. If flash is writable, the PCDs are set to point
> at the flash memory. If flash is not writable, the PCDs are set to
> point at a memory buffer.
Can you please state the use case for the latter option? That is, when
the PCDs are set to point at the memory buffer.
In that case, the memory buffer is guaranteed to be empty (modulo
internal formatting that PlatformPei would do just-in-time), unless the
VM has just been rebooted within the same QEMU instance.
In other words, clients of the r/o variable2 PPI will get false results,
most of the time -- if I understand correctly. After a fresh boot (which
is most of the boots), no variable will be found in the PEI phase, even
if the \NvVars file contains it, and the variable services in DXE will
later find it.
... I'm not sure if my understanding above is correct, but if it is,
then I think this feature only contributes to the confusing nature of
the memory-emulated variables.
Thanks
Laszlo
>
> I tested KVM with ROM and writable flash, with S3 sleep/resume. I did
> not test SMM.
>
> Jordan Justen (10):
> OvmfPkg/build.sh: Add support for --disable-flash switch
> OvmfPkg QemuFlash: Make QemuFlash.* Base class safe
> OvmfPkg QemuFlash: Make QemuFlashDetected external
> OvmfPkg QemuFlash: Add DetectFlashBaseLib.inf 'NULL' library
> OvmfPkg PlatformPei: Detect and set PcdOvmfFlashVariablesEnable
> OvmfPkg/EmuVariableFvbRuntimeDxe: Use PcdOvmfFlashVariablesEnable
> OvmfPkg PlatformPei: Set flash variable PCDs
> OvmfPkg PlatformPei: Initialize memory based variable store buffer
> OvmfPkg: Enable PEI variable access
> OvmfPkg QemuFlashFvbServicesRuntimeDxe: Cleanup init now done in PEI
>
> Laszlo Ersek (2):
> OvmfPkg: resolve PcdLib for all PEIMs individually
> OvmfPkg: resolve PcdLib for PEIMs to PeiPcdLib by default
>
> OvmfPkg/EmuVariableFvbRuntimeDxe/Fvb.c | 4 +-
> OvmfPkg/EmuVariableFvbRuntimeDxe/Fvb.inf | 3 +-
> OvmfPkg/OvmfPkgIa32.dsc | 27 +-
> OvmfPkg/OvmfPkgIa32.fdf | 5 +-
> OvmfPkg/OvmfPkgIa32X64.dsc | 27 +-
> OvmfPkg/OvmfPkgIa32X64.fdf | 5 +-
> OvmfPkg/OvmfPkgX64.dsc | 27 +-
> OvmfPkg/OvmfPkgX64.fdf | 5 +-
> OvmfPkg/PlatformPei/Platform.c | 34 +--
> OvmfPkg/PlatformPei/Platform.h | 7 +-
> OvmfPkg/PlatformPei/PlatformPei.inf | 11 +-
> OvmfPkg/PlatformPei/Vars.c | 283 +++++++++++++++++++++
> .../DetectFlashNullLib.c | 41 +++
> .../DetectFlashNullLib.inf | 60 +++++
> .../FvbServicesRuntimeDxe.inf | 4 -
> .../FvbServicesSmm.inf | 4 -
> .../FwBlockService.c | 28 +-
> OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlash.c | 59 +++--
> OvmfPkg/QemuFlashFvbServicesRuntimeDxe/QemuFlash.h | 30 ++-
> OvmfPkg/build.sh | 10 +-
> 20 files changed, 530 insertions(+), 144 deletions(-)
> create mode 100644 OvmfPkg/PlatformPei/Vars.c
> create mode 100644 OvmfPkg/QemuFlashFvbServicesRuntimeDxe/DetectFlashNullLib.c
> create mode 100644 OvmfPkg/QemuFlashFvbServicesRuntimeDxe/DetectFlashNullLib.inf
>
next prev parent reply other threads:[~2017-03-27 18:03 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-27 8:05 [PATCH 00/12] OvmfPkg: Enable variable access in PEI Jordan Justen
2017-03-27 8:05 ` [PATCH 01/12] OvmfPkg/build.sh: Add support for --disable-flash switch Jordan Justen
2017-03-27 8:05 ` [PATCH 02/12] OvmfPkg: resolve PcdLib for all PEIMs individually Jordan Justen
2017-03-27 8:05 ` [PATCH 03/12] OvmfPkg: resolve PcdLib for PEIMs to PeiPcdLib by default Jordan Justen
2017-03-27 8:05 ` [PATCH 04/12] OvmfPkg QemuFlash: Make QemuFlash.* Base class safe Jordan Justen
2017-03-27 8:05 ` [PATCH 05/12] OvmfPkg QemuFlash: Make QemuFlashDetected external Jordan Justen
2017-03-27 8:05 ` [PATCH 06/12] OvmfPkg QemuFlash: Add DetectFlashBaseLib.inf 'NULL' library Jordan Justen
2017-03-27 8:05 ` [PATCH 07/12] OvmfPkg PlatformPei: Detect and set PcdOvmfFlashVariablesEnable Jordan Justen
2017-03-27 8:05 ` [PATCH 08/12] OvmfPkg/EmuVariableFvbRuntimeDxe: Use PcdOvmfFlashVariablesEnable Jordan Justen
2017-03-27 8:05 ` [PATCH 09/12] OvmfPkg PlatformPei: Set flash variable PCDs Jordan Justen
2017-03-27 8:05 ` [PATCH 10/12] OvmfPkg PlatformPei: Initialize memory based variable store buffer Jordan Justen
2017-03-27 8:05 ` [PATCH 11/12] OvmfPkg: Enable PEI variable access Jordan Justen
2017-03-27 8:05 ` [PATCH 12/12] OvmfPkg QemuFlashFvbServicesRuntimeDxe: Cleanup init now done in PEI Jordan Justen
2017-03-27 18:03 ` Laszlo Ersek [this message]
2017-03-27 21:47 ` [PATCH 00/12] OvmfPkg: Enable variable access " Jordan Justen
2017-03-28 9:22 ` Laszlo Ersek
2017-03-29 5:24 ` Jordan Justen
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