Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit c37c9044 authored by Gil Dekel's avatar Gil Dekel
Browse files

SF: Parse, hash, and cache block 0 serial number 

More EDID fields are required as a part of migrating to EDID-based
display IDs. This CL parses the device's serial number from bytes 12-15
of block 0 in the EDID blob, hashes it using a stable hash, and serves
it as a part of the Edid struct.

Later, amongst others, this value will be used to fabricate a unique
display ID that is based on the display's EDID.

See:
1. EDID spec: https://glenwing.github.io/docs/VESA-EEDID-A2.pdf
2. https://en.wikipedia.org/wiki/Extended_Display_Identification_Data#Structure,_version_1.4

Flag: com.android.graphics.surfaceflinger.flags.stable_edid_ids
Bug: 378923334
Test: DisplayIdentification_test
Change-Id: I8e5c79f2f51c2fd2085dfaba7f5c45fbc698cbcb
parent 3e96f94d

libs/ui/DisplayIdentification.cpp

+19 −0
Original line number Diff line number Diff line
@@ -19,9 +19,12 @@ 


#include <algorithm>

#include <cctype>

#include <cstdint>

#include <numeric>

#include <optional>

#include <span>

#include <string>

#include <string_view>



#include <ftl/hash.h>

#include <log/log.h>
@@ -194,6 +197,21 @@ std::optional<Edid> parseEdid(const DisplayIdentificationData& edid) { 
    const uint16_t productId =

            static_cast<uint16_t>(edid[kProductIdOffset] | (edid[kProductIdOffset + 1] << 8));



    //   Bytes 12-15: display serial number, in little-endian (LSB). This field is

    //   optional and its absence is marked by having all bytes set to 0x00.

    //   Values do not represent ASCII characters.

    constexpr size_t kSerialNumberOffset = 12;

    if (edid.size() < kSerialNumberOffset + sizeof(uint32_t)) {

        ALOGE("Invalid EDID: block zero S/N is truncated.");

        return {};

    }

    const uint32_t blockZeroSerialNumber = edid[kSerialNumberOffset] +

            (edid[kSerialNumberOffset + 1] << 8) + (edid[kSerialNumberOffset + 2] << 16) +

            (edid[kSerialNumberOffset + 3] << 24);

    const auto hashedBlockZeroSNOpt = blockZeroSerialNumber == 0

            ? std::nullopt

            : ftl::stable_hash(std::string_view(std::to_string(blockZeroSerialNumber)));



    constexpr size_t kManufactureWeekOffset = 16;

    if (edid.size() < kManufactureWeekOffset + sizeof(uint8_t)) {

        ALOGE("Invalid EDID: manufacture week is truncated.");
@@ -350,6 +368,7 @@ std::optional<Edid> parseEdid(const DisplayIdentificationData& edid) { 
    return Edid{

            .manufacturerId = manufacturerId,

            .productId = productId,

            .hashedBlockZeroSerialNumberOpt = hashedBlockZeroSNOpt,

            .pnpId = *pnpId,

            .modelHash = modelHash,

            .displayName = displayName,

libs/ui/include/ui/DisplayIdentification.h

+1 −0
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ struct Cea861ExtensionBlock : ExtensionBlock { 
struct Edid {

    uint16_t manufacturerId;

    uint16_t productId;

    std::optional<uint64_t> hashedBlockZeroSerialNumberOpt;

    PnpId pnpId;

    uint32_t modelHash;

    std::string_view displayName;

libs/ui/tests/DisplayIdentification_test.cpp

+14 −3
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@ namespace android { 
namespace {



const unsigned char kInternalEdid[] =

        "\x00\xff\xff\xff\xff\xff\xff\x00\x4c\xa3\x42\x31\x00\x00\x00\x00"

        "\x00\xff\xff\xff\xff\xff\xff\x00\x4c\xa3\x42\x31\x4e\x61\xbc\x00"

        "\x00\x15\x01\x03\x80\x1a\x10\x78\x0a\xd3\xe5\x95\x5c\x60\x90\x27"

        "\x19\x50\x54\x00\x00\x00\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01"

        "\x01\x01\x01\x01\x01\x01\x9e\x1b\x00\xa0\x50\x20\x12\x30\x10\x30"
@@ -54,7 +54,7 @@ const unsigned char kExternalEdid[] = 


// Extended EDID with timing extension.

const unsigned char kExternalEedid[] =

        "\x00\xff\xff\xff\xff\xff\xff\x00\x4c\x2d\xfe\x08\x00\x00\x00\x00"

        "\x00\xff\xff\xff\xff\xff\xff\x00\x4c\x2d\xfe\x08\xb1\x7f\x39\x05"

        "\x29\x15\x01\x03\x80\x10\x09\x78\x0a\xee\x91\xa3\x54\x4c\x99\x26"

        "\x0f\x50\x54\xbd\xef\x80\x71\x4f\x81\xc0\x81\x00\x81\x80\x95\x00"

        "\xa9\xc0\xb3\x00\x01\x01\x02\x3a\x80\x18\x71\x38\x2d\x40\x58\x2c"
@@ -112,7 +112,7 @@ const unsigned char kHisenseTvEdid[] = 
        "\x07";



const unsigned char kCtlDisplayEdid[] =

        "\x00\xff\xff\xff\xff\xff\xff\x00\x0e\x8c\x9d\x24\x00\x00\x00\x00"

        "\x00\xff\xff\xff\xff\xff\xff\x00\x0e\x8c\x9d\x24\x30\x41\xab\x00"

        "\xff\x17\x01\x04\xa5\x34\x1d\x78\x3a\xa7\x25\xa4\x57\x51\xa0\x26"

        "\x10\x50\x54\xbf\xef\x80\xb3\x00\xa9\x40\x95\x00\x81\x40\x81\x80"

        "\x95\x0f\x71\x4f\x90\x40\x02\x3a\x80\x18\x71\x38\x2d\x40\x58\x2c"
@@ -191,6 +191,8 @@ TEST(DisplayIdentificationTest, parseEdid) { 
    EXPECT_EQ(hash("121AT11-801"), 626564263);

    EXPECT_TRUE(edid->displayName.empty());

    EXPECT_EQ(12610, edid->productId);

    EXPECT_TRUE(edid->hashedBlockZeroSerialNumberOpt.has_value());

    EXPECT_EQ(ftl::stable_hash("12345678"), edid->hashedBlockZeroSerialNumberOpt.value());

    EXPECT_EQ(21, edid->manufactureOrModelYear);

    EXPECT_EQ(0, edid->manufactureWeek);

    EXPECT_EQ(26, edid->physicalSizeInCm.width);
@@ -209,6 +211,8 @@ TEST(DisplayIdentificationTest, parseEdid) { 
    EXPECT_EQ(hash("HP ZR30w"), 918492362);

    EXPECT_EQ("HP ZR30w", edid->displayName);

    EXPECT_EQ(10348, edid->productId);

    EXPECT_TRUE(edid->hashedBlockZeroSerialNumberOpt.has_value());

    EXPECT_EQ(ftl::stable_hash("16843009"), edid->hashedBlockZeroSerialNumberOpt.value());

    EXPECT_EQ(22, edid->manufactureOrModelYear);

    EXPECT_EQ(2, edid->manufactureWeek);

    EXPECT_EQ(64, edid->physicalSizeInCm.width);
@@ -227,6 +231,8 @@ TEST(DisplayIdentificationTest, parseEdid) { 
    EXPECT_EQ(hash("SAMSUNG"), 1201368132);

    EXPECT_EQ("SAMSUNG", edid->displayName);

    EXPECT_EQ(2302, edid->productId);

    EXPECT_TRUE(edid->hashedBlockZeroSerialNumberOpt.has_value());

    EXPECT_EQ(ftl::stable_hash("87654321"), edid->hashedBlockZeroSerialNumberOpt.value());

    EXPECT_EQ(21, edid->manufactureOrModelYear);

    EXPECT_EQ(41, edid->manufactureWeek);

    EXPECT_EQ(16, edid->physicalSizeInCm.width);
@@ -251,6 +257,8 @@ TEST(DisplayIdentificationTest, parseEdid) { 
    EXPECT_EQ(hash("Panasonic-TV"), 3876373262);

    EXPECT_EQ("Panasonic-TV", edid->displayName);

    EXPECT_EQ(41622, edid->productId);

    EXPECT_TRUE(edid->hashedBlockZeroSerialNumberOpt.has_value());

    EXPECT_EQ(ftl::stable_hash("16843009"), edid->hashedBlockZeroSerialNumberOpt.value());

    EXPECT_EQ(29, edid->manufactureOrModelYear);

    EXPECT_EQ(0, edid->manufactureWeek);

    EXPECT_EQ(128, edid->physicalSizeInCm.width);
@@ -275,6 +283,7 @@ TEST(DisplayIdentificationTest, parseEdid) { 
    EXPECT_EQ(hash("Hisense"), 2859844809);

    EXPECT_EQ("Hisense", edid->displayName);

    EXPECT_EQ(0, edid->productId);

    EXPECT_FALSE(edid->hashedBlockZeroSerialNumberOpt.has_value());

    EXPECT_EQ(29, edid->manufactureOrModelYear);

    EXPECT_EQ(18, edid->manufactureWeek);

    EXPECT_EQ(0, edid->physicalSizeInCm.width);
@@ -299,6 +308,8 @@ TEST(DisplayIdentificationTest, parseEdid) { 
    EXPECT_EQ(hash("LP2361"), 1523181158);

    EXPECT_EQ("LP2361", edid->displayName);

    EXPECT_EQ(9373, edid->productId);

    EXPECT_TRUE(edid->hashedBlockZeroSerialNumberOpt.has_value());

    EXPECT_EQ(ftl::stable_hash("11223344"), edid->hashedBlockZeroSerialNumberOpt.value());

    EXPECT_EQ(23, edid->manufactureOrModelYear);

    EXPECT_EQ(0xff, edid->manufactureWeek);

    EXPECT_EQ(52, edid->physicalSizeInCm.width);