[PATCH 1/4] OvmfPkg/Tcg2ConfigPei: introduce a signalling PPI to depex on

["Ard Biesheuvel" <ard.biesheuvel@linaro.org>]

On ARM systems, the TPM does not live at a fixed address, and so we
need the platform to discover it first. So introduce a PPI that signals
that the TPM address has been discovered and recorded in the appropriate
PCD, and make Tcg2ConfigPei depex on it when built for ARM or AARCH64.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 OvmfPkg/OvmfPkg.dec                      | 4 ++++
 OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf | 6 +++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
index d5fee805ef4a..10a2b714c1b4 100644
--- a/OvmfPkg/OvmfPkg.dec
+++ b/OvmfPkg/OvmfPkg.dec
@@ -101,6 +101,10 @@ [Protocols]
   gEfiLegacyInterruptProtocolGuid     = {0x31ce593d, 0x108a, 0x485d, {0xad, 0xb2, 0x78, 0xf2, 0x1f, 0x29, 0x66, 0xbe}}
   gEfiVgaMiniPortProtocolGuid         = {0xc7735a2f, 0x88f5, 0x4882, {0xae, 0x63, 0xfa, 0xac, 0x8c, 0x8b, 0x86, 0xb3}}
 
+[Ppis]
+  # PPI whose presence in the PPI database signals that the TPM base address has been discovered and recorded
+  gOvmfTpmDiscoveredPpiGuid           = {0xb9a61ad0, 0x2802, 0x41f3, {0xb5, 0x13, 0x96, 0x51, 0xce, 0x6b, 0xd5, 0x75}}
+
 [PcdsFixedAtBuild]
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfPeiMemFvBase|0x0|UINT32|0
   gUefiOvmfPkgTokenSpaceGuid.PcdOvmfPeiMemFvSize|0x0|UINT32|1
diff --git a/OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf b/OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf
index e34cd6210611..55684ba045b3 100644
--- a/OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf
+++ b/OvmfPkg/Tcg/Tcg2Config/Tcg2ConfigPei.inf
@@ -25,6 +25,7 @@ [Sources]
 [Packages]
   MdePkg/MdePkg.dec
   MdeModulePkg/MdeModulePkg.dec
+  OvmfPkg/OvmfPkg.dec
   SecurityPkg/SecurityPkg.dec
 
 [LibraryClasses]
@@ -43,5 +44,8 @@ [Ppis]
 [Pcd]
   gEfiSecurityPkgTokenSpaceGuid.PcdTpmInstanceGuid                 ## PRODUCES
 
-[Depex]
+[Depex.IA32, Depex.X64]
   TRUE
+
+[Depex.ARM, Depex.AARCH64]
+  gOvmfTpmDiscoveredPpiGuid
-- 
2.20.1