As described in the Xen PVH documentation [1], "ebx: contains the
physical memory address where the loader has placed the boot start info
structure". To have this pointer saved to be able to use it later in the
PEI phase, we allocate some space in the MEMFD for it. We use 'XPVH' as
a signature (for "Xen PVH").
[1] https://xenbits.xenproject.org/docs/unstable/misc/pvh.html
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-8-anthony.perard@citrix.com>
Add a new entry point for Xen PVH that enter directly in 32bits.
Information on the expected state of the machine when this entry point
is used can be found at:
https://xenbits.xenproject.org/docs/unstable/misc/pvh.html
Also, compare to the original file [1], the two `nop' of the "resetVector"
entry point are removed. There were introduced by 8332983e2e
("UefiCpuPkg: Replace the un-necessary WBINVD instruction at the reset
vector with two NOPs in VTF0.", 2011-08-04), but don't seems to be
useful. This is the entry point used by HVM guest (hvmloader).
[1] UefiCpuPkg/ResetVector/Vtf0/Ia16/ResetVectorVtf0.asm
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-7-anthony.perard@citrix.com>
Introduce XenResetVector, a copy of OvmfPkg/ResetVector, with one
changes:
- SEC_DEFAULT_CR0: enable cache (bit 30 or CD set to 0)
Xen copies the OVMF code to RAM, there is no need to disable cache.
This new module will later be modified to add a new entry point, more
detail in a following commit "OvmfPkg/XenResetVector: Add new entry point
for Xen PVH"
Value FILE_GUID of XenResetVector have not changed compare to ResetVector
because it is a special value (gEfiFirmwareVolumeTopFileGuid).
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1689
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20190813113119.14804-4-anthony.perard@citrix.com>
Anthony PERARD