This repo contains almost everything (except for the usbser.sys driver because of Microsoft Software License Terms) that is needed to create a lowcdc.sys driver package that can be installed on the 64-bit version of Windows 10. lowcdc.sys is published unchanged, the source code is available on the author's site (see the Credits section).

The driver package supports the following devices:

• AVR-CDC (USB\VID_16C0&PID_05E1),

• Digispark (USB\VID_16D0&PID_087E).

The master branch can be broken, use tags/releases in order to obtain stable releases.

I'm not very proficient in English, please consider helping with the translation. You can send a pull request, participate in the discussion or send me an email.

1. The lowcdc.inf installation script does not contain necessary sections (SourceDisksNames, SourceDisksFiles), the driver package does not contain a signed catalog file.

2. usbser.sys has been completely re-written in Windows 10 and cannot be used with the current version of the lowcdc.sys.

3. Beginning with the release of Windows 10, all new Windows 10 kernel mode drivers must be submitted to and digitally signed by the Windows Hardware Developer Center Dashboard portal.

1. Find usbser.sys included in the 64-bit version of Windows 7. The file is located in the \Sources\install.wim\Windows\System32\DriverStore\FileRepository\mdmcpq.inf_amd64_neutral_fbc4a14a6a13d0c8\ folder on the installation disk of Windows 7 with integrated SP1. The version of the driver I use is 6.1.7610.17514. Copy the file to the driver package's folder and rename it to usbser61.sys to avoid replacement of the Windows 10 driver.

2. Install Windows Driver Kit (WDK) 10. Make sure that the Inf2Cat program is located in the \Program Files (x86)\Windows Kits\10\Bin\x86\ folder, the programs MakeCert, CertMgr, SignTool are located in the \Program Files (x86)\Windows Kits\10\Bin\x64\ folder. If any program is missing, try to install Windows 10 SDK.

3. Enable the TESTSIGNING boot configuration option, restart the computer for the change to take effect. When the option for test-signing is enabled Windows displays a watermark with the text "Test Mode", the version and build of Windows in the lower right-hand corner of the desktop. Be aware using Windows with the TESTSIGNING boot configuration option, Windows will load any type of test-signed kernel-mode code.

4. Create a catalog file for the driver package.

5. Create a MakeCert test certificate, install the test certificate to corresponding certificate stores, test-sign the driver package's catalog file.

createcat.bat is a script that generates a test-signed catalog file for the driver package (performs the actions 4 and 5 from the list above).

The script does not need any configuration and ready for use. However you can change the name of a certificate (the CertName variable) or use an installed certificate (change the CertName variable, set CreateCert=0).

1. Run createcat.bat with the administrative permissions (it is not necessary to run the script in the command prompt).

2. Examine the output. The text below is the result of a successful execution.

D:\LowCDC-Win10x64>createcat.bat

D:\LowCDC-Win10x64>cd /D C:\Program Files (x86)\Windows Kits\10\Bin\x86

C:\Program Files (x86)\Windows Kits\10\bin\x86>Inf2Cat /driver:"D:\LowCDC-Win10x64" /os:10_X64
.................................
Signability test complete.

Errors:
None

Warnings:
None

Catalog generation complete.
D:\LowCDC-Win10x64\lowcdc.cat

C:\Program Files (x86)\Windows Kits\10\bin\x86>cd ..\x64

C:\Program Files (x86)\Windows Kits\10\bin\x64>if 1 EQU 1 (if not exist "D:\LowCDC-Win10x64\certcopy.cer" (
MakeCert -r -pe -ss CA -n "CN=createcat.bat autogenerated certificate" "D:\LowCDC-Win10x64\certcopy.cer"
 CertMgr /add "D:\LowCDC-Win10x64\certcopy.cer" /s /r localMachine root
 CertMgr /add "D:\LowCDC-Win10x64\certcopy.cer" /s /r localMachine trustedpublisher
) )
Succeeded
CertMgr Succeeded
CertMgr Succeeded

C:\Program Files (x86)\Windows Kits\10\bin\x64>SignTool sign /v /s CA /n "createcat.bat autogenerated certificate" /t http://timestamp.verisign.com/scripts/timstamp.dll "D:\LowCDC-Win10x64\lowcdc.cat"
The following certificate was selected:
    Issued to: createcat.bat autogenerated certificate
    Issued by: createcat.bat autogenerated certificate
    Expires:   Sun Jan 01 02:59:59 2040
    SHA1 hash: 91E7FC5F14E0AEEE3211E438A01DA07BB9959091

Done Adding Additional Store
Successfully signed: D:\LowCDC-Win10x64\lowcdc.cat

Number of files successfully Signed: 1
Number of warnings: 0
Number of errors: 0

C:\Program Files (x86)\Windows Kits\10\bin\x64>SignTool verify /v /pa "D:\LowCDC-Win10x64\lowcdc.cat"

Verifying: D:\LowCDC-Win10x64\lowcdc.cat
Signature Index: 0 (Primary Signature)
Hash of file (sha1): 0CA6677A0F8F5F7E05B8331DC5C662E9B6ABC24C

Signing Certificate Chain:
    Issued to: createcat.bat autogenerated certificate
    Issued by: createcat.bat autogenerated certificate
    Expires:   Sun Jan 01 02:59:59 2040
    SHA1 hash: 91E7FC5F14E0AEEE3211E438A01DA07BB9959091

The signature is timestamped: Sat Jan 16 08:36:20 2016
Timestamp Verified by:
    Issued to: Thawte Timestamping CA
    Issued by: Thawte Timestamping CA
    Expires:   Fri Jan 01 02:59:59 2021
    SHA1 hash: BE36A4562FB2EE05DBB3D32323ADF445084ED656

        Issued to: Symantec Time Stamping Services CA - G2
        Issued by: Thawte Timestamping CA
        Expires:   Thu Dec 31 02:59:59 2020
        SHA1 hash: 6C07453FFDDA08B83707C09B82FB3D15F35336B1

            Issued to: Symantec Time Stamping Services Signer - G4
            Issued by: Symantec Time Stamping Services CA - G2
            Expires:   Wed Dec 30 02:59:59 2020
            SHA1 hash: 65439929B67973EB192D6FF243E6767ADF0834E4


Successfully verified: D:\LowCDC-Win10x64\lowcdc.cat

Number of files successfully Verified: 1
Number of warnings: 0
Number of errors: 0

C:\Program Files (x86)\Windows Kits\10\bin\x64>cd /D D:\LowCDC-Win10x64

createcat.bat generates the test-signed catalog file lowcdc.cat and creates the certcopy.cer file that contains a copy of the certificate.

A common issue that can be encountered is the 0x800B0101 error.

SignTool Error: WinVerifyTrust returned error: 0x800B0101
        A required certificate is not within its validity period when verifying against the current system clock or the timestamp in the signed file.

Open lowcdc.cat, compare the singing time of the catalog file and the value of the certificate's 'valid from'. Adjust the system clock. Run createcat.bat again (do not delete certcopy.cer, the file is used to determine whether the certificate has been created and added to the certificate stores, otherwise set CreateCert=0).

The installed driver in Device Manager.

Communication with the MicroProg programmer.

Communication with the STK500 compatible programmer.

lowcdc.sys is developed by Osamu Tamura.