On 2018-08-02 17:30:45, Laszlo Ersek wrote: > The DXE Core is one of those modules that call > ProcessLibraryConstructorList() manually. > > Before DxeMain() [MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c] calls > ProcessLibraryConstructorList(), and through it, our > PlatformDebugLibIoPortConstructor() function, DxeMain() invokes the > DEBUG() macro multiple times. That macro lands in our > PlatformDebugLibIoPortFound() function -- which currently relies on the > "mDebugIoPortFound" global variable that has (not yet) been set by the > constructor. As a result, early debug messages from the DXE Core are lost. > > Move the device detection into PlatformDebugLibIoPortFound(), also caching > the fact (not just the result) of the device detection. > > (We could introduce a separate DebugLib instance just for the DXE Core, > but the above approach works for all modules that currently consume the > PlatformDebugLibIoPort instance (which means "everything but SEC").) > > This restores messages such as: > > > CoreInitializeMemoryServices: > > BaseAddress - 0x7AF21000 Length - 0x3CDE000 MinimalMemorySizeNeeded - > > 0x10F4000 > > Keep the empty constructor function -- OVMF's DebugLib instances have > always had constructors; we had better not upset constructor dependency > ordering by making our instance(s) constructor-less. > > Cc: Ard Biesheuvel <[email protected]> > Cc: Brijesh Singh <[email protected]> > Cc: Jordan Justen <[email protected]> > Fixes: c09d9571300a089c35f5df2773b70edc25050d0d > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Laszlo Ersek <[email protected]> > --- > > Notes: > Brijesh, can you please test this patch on SEV, with and without > capturing the debug port? (In the first case, the debug log should just > work; in the second case, the boot should remain fast.) Thanks! > > Repo: https://github.com/lersek/edk2.git > Branch: debuglib_dxecore > > OvmfPkg/Library/PlatformDebugLibIoPort/DebugLibDetect.c | 24 > ++++++++++++++++---- > 1 file changed, 20 insertions(+), 4 deletions(-) > > diff --git a/OvmfPkg/Library/PlatformDebugLibIoPort/DebugLibDetect.c > b/OvmfPkg/Library/PlatformDebugLibIoPort/DebugLibDetect.c > index 81c44eece95f..74aef2e37b42 100644 > --- a/OvmfPkg/Library/PlatformDebugLibIoPort/DebugLibDetect.c > +++ b/OvmfPkg/Library/PlatformDebugLibIoPort/DebugLibDetect.c > @@ -16,14 +16,26 @@ > #include <Base.h> > #include "DebugLibDetect.h" > > + > +// > +// Set to TRUE if the debug I/O port has been checked > +// > +STATIC BOOLEAN mDebugIoPortChecked = FALSE;
Could this be a static variable in the function? If not, should it be follow by a blank line? I agree that Brijesh should verify it, but pending that: Reviewed-by: Jordan Justen <[email protected]> > // > // Set to TRUE if the debug I/O port is enabled > // > STATIC BOOLEAN mDebugIoPortFound = FALSE; > > /** > - This constructor function checks if the debug I/O port device is present, > - caching the result for later use. > + This constructor function must not do anything. > + > + Some modules consuming this library instance, such as the DXE Core, invoke > + the DEBUG() macro before they explicitly call > + ProcessLibraryConstructorList(). Therefore the auto-generated call from > + ProcessLibraryConstructorList() to this constructor function may be > preceded > + by some calls to PlatformDebugLibIoPortFound() below. Hence > + PlatformDebugLibIoPortFound() must not rely on anything this constructor > + could set up. > > @retval RETURN_SUCCESS The constructor always returns RETURN_SUCCESS. > > @@ -34,12 +46,12 @@ PlatformDebugLibIoPortConstructor ( > VOID > ) > { > - mDebugIoPortFound = PlatformDebugLibIoPortDetect(); > return RETURN_SUCCESS; > } > > /** > - Return the cached result of detecting the debug I/O port device. > + At the first call, check if the debug I/O port device is present, and cache > + the result for later use. At subsequent calls, return the cached result. > > @retval TRUE if the debug I/O port device was detected. > @retval FALSE otherwise > @@ -51,5 +63,9 @@ PlatformDebugLibIoPortFound ( > VOID > ) > { > + if (!mDebugIoPortChecked) { > + mDebugIoPortFound = PlatformDebugLibIoPortDetect (); > + mDebugIoPortChecked = TRUE; > + } > return mDebugIoPortFound; > } > -- > 2.14.1.3.gb7cf6e02401b > _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
