Merge "SF: Add EDID-ID Fabrication Logic" into main
diff --git a/libs/ui/DisplayIdentification.cpp b/libs/ui/DisplayIdentification.cpp
index ee38f50..b7ef9b3 100644
--- a/libs/ui/DisplayIdentification.cpp
+++ b/libs/ui/DisplayIdentification.cpp
@@ -26,6 +26,7 @@
#include <string>
#include <string_view>
+#include <ftl/concat.h>
#include <ftl/hash.h>
#include <log/log.h>
#include <ui/DisplayIdentification.h>
@@ -423,4 +424,27 @@
return PhysicalDisplayId::fromEdid(0, kVirtualEdidManufacturerId, id);
}
+PhysicalDisplayId generateEdidDisplayId(const Edid& edid) {
+ const ftl::Concat displayDetailsString{edid.manufacturerId,
+ edid.productId,
+ ftl::truncated<13>(edid.displayName),
+ edid.manufactureWeek,
+ edid.manufactureOrModelYear,
+ edid.physicalSizeInCm.getWidth(),
+ edid.physicalSizeInCm.getHeight()};
+
+ // String has to be cropped to 64 characters (at most) for ftl::stable_hash.
+ // This is fine as the accuracy or completeness of the above fields is not
+ // critical for a ID fabrication.
+ const std::optional<uint64_t> hashedDisplayDetailsOpt =
+ ftl::stable_hash(std::string_view(displayDetailsString.c_str(), 64));
+
+ // Combine the hashes via bit-shifted XORs.
+ const uint64_t id = (hashedDisplayDetailsOpt.value_or(0) << 17) ^
+ (edid.hashedBlockZeroSerialNumberOpt.value_or(0) >> 11) ^
+ (edid.hashedDescriptorBlockSerialNumberOpt.value_or(0) << 23);
+
+ return PhysicalDisplayId::fromEdidHash(id);
+}
+
} // namespace android
diff --git a/libs/ui/include/ui/DisplayId.h b/libs/ui/include/ui/DisplayId.h
index 9ea6cec..13ed754 100644
--- a/libs/ui/include/ui/DisplayId.h
+++ b/libs/ui/include/ui/DisplayId.h
@@ -81,12 +81,17 @@
return PhysicalDisplayId(id);
}
- // Returns a stable ID based on EDID information.
+ // Returns a stable ID based on EDID and port information.
static constexpr PhysicalDisplayId fromEdid(uint8_t port, uint16_t manufacturerId,
uint32_t modelHash) {
return PhysicalDisplayId(FLAG_STABLE, port, manufacturerId, modelHash);
}
+ // Returns a stable and consistent ID based exclusively on EDID information.
+ static constexpr PhysicalDisplayId fromEdidHash(uint64_t hashedEdid) {
+ return PhysicalDisplayId(hashedEdid);
+ }
+
// Returns an unstable ID. If EDID is available using "fromEdid" is preferred.
static constexpr PhysicalDisplayId fromPort(uint8_t port) {
constexpr uint16_t kManufacturerId = 0;
@@ -103,6 +108,8 @@
// Flag indicating that the ID is stable across reboots.
static constexpr uint64_t FLAG_STABLE = 1ULL << 62;
+ using DisplayId::DisplayId;
+
constexpr PhysicalDisplayId(uint64_t flags, uint8_t port, uint16_t manufacturerId,
uint32_t modelHash)
: DisplayId(flags | (static_cast<uint64_t>(manufacturerId) << 40) |
diff --git a/libs/ui/include/ui/DisplayIdentification.h b/libs/ui/include/ui/DisplayIdentification.h
index 5883dba..1e3449c 100644
--- a/libs/ui/include/ui/DisplayIdentification.h
+++ b/libs/ui/include/ui/DisplayIdentification.h
@@ -74,6 +74,7 @@
std::optional<uint64_t> hashedDescriptorBlockSerialNumberOpt;
PnpId pnpId;
uint32_t modelHash;
+ // Up to 13 characters of ASCII text terminated by LF and padded with SP.
std::string_view displayName;
uint8_t manufactureOrModelYear;
uint8_t manufactureWeek;
@@ -91,4 +92,8 @@
PhysicalDisplayId getVirtualDisplayId(uint32_t id);
+// Generates a consistent, stable, and hashed display ID that is based on the
+// display's parsed EDID fields.
+PhysicalDisplayId generateEdidDisplayId(const Edid& edid);
+
} // namespace android
diff --git a/libs/ui/tests/DisplayIdentification_test.cpp b/libs/ui/tests/DisplayIdentification_test.cpp
index fdcf112..75c71a5 100644
--- a/libs/ui/tests/DisplayIdentification_test.cpp
+++ b/libs/ui/tests/DisplayIdentification_test.cpp
@@ -376,6 +376,22 @@
EXPECT_EQ(4633127902230889474, tertiaryInfo->id.value);
}
+TEST(DisplayIdentificationTest, generateEdidDisplayId) {
+ const auto firstExternalDisplayEdidOpt = parseEdid(getExternalEdid());
+ ASSERT_TRUE(firstExternalDisplayEdidOpt);
+ const PhysicalDisplayId firstExternalDisplayId =
+ generateEdidDisplayId(firstExternalDisplayEdidOpt.value());
+
+ const auto secondExternalDisplayEdidOpt = parseEdid(getExternalEedid());
+ ASSERT_TRUE(secondExternalDisplayEdidOpt);
+ const PhysicalDisplayId secondExternalDisplayId =
+ generateEdidDisplayId(secondExternalDisplayEdidOpt.value());
+
+ // Display IDs should be unique.
+ EXPECT_EQ(4067182673952280501u, firstExternalDisplayId.value);
+ EXPECT_EQ(14712168404707886855u, secondExternalDisplayId.value);
+}
+
TEST(DisplayIdentificationTest, deviceProductInfo) {
using ManufactureYear = DeviceProductInfo::ManufactureYear;
using ManufactureWeekAndYear = DeviceProductInfo::ManufactureWeekAndYear;