Project Stellar - Firmware Update 1.1.0

Project Stellar - Firmware Update 1.1.0

Hey everyone! A lot has happened since our last update, and it's time for another exciting update. A little over two weeks ago, we announced that we were putting a short pause on shipments to focus on support for Project Stellar...

Today we are happy to announce that shipping has resumed and that a new firmware update for Project Stellar is available. This is the most significant update to Project Stellar since its launch, and we are excited to share it with you.

The last two weeks have focused on bug fixes and quality-of-life improvements. However, we've also managed to squeeze in a few new features. This will be a long one, so make sure to stick around until the end!

Legacy and Extended Partition Support

By far, the biggest feature request for Project Stellar has been support for legacy and extended partitions...

When we first started the development of Project Stellar, three of the designs goals were to re-evaluate everything, keep things simple, and make Project Stellar as user-friendly as possible. This meant that we wanted to re-evaluate the partitioning scheme used by modded Xboxes.

Most modded Xboxes use a partitioning scheme that is based on the work of oz_paulb. This is a great design and has served the community well for many years. However, it does have some drawbacks.

We had originally planned to re-evaluate and roll out our own solution. However, this was put on the back burner due to time constraints, and instead, we launched with only supporting "All on F" as the only supported extended partitioning option.

Hindsight is 20/20, and we now realize that we should have just supported the legacy partitioning scheme from the start.

With the 1.1.0 release, StellarOS now supports both legacy and extended partitions. This includes supporting all past and current drive configurations.

Built-in HDD Formatting

With the 1.1.0 release, StellarOS now includes a built-in HDD formatting tool. This tool lets you format your HDD to the Xbox native FATX filesystem using the extended LBAv2 partitioning table. This tool is useful for formatting a new HDD or reformatting an existing one.

The formatting tool can format the entire HDD or just the extended partition. The latter is useful if you want to keep the contents of the retail partitions intact.

Timezone and Date/Time Settings

One of the goals of Project Stellar is to be completely self-contained. This means the Xbox dashboard is no longer needed to configure the system. And one of the last parts of the dashboard that was needed was the date and time settings. With StellarOS, the date and time can now be configured from the StellarOS settings.

US Daylight Savings Time Fixed

In 2005 the US government changed the dates for daylight savings time. This change was never reflected in the Xbox dashboard, and as a result, the Xbox will always be an hour off during daylight savings time. StellarOS fixes this by correcting the timezone offset during daylight savings time.

Stellar-Enhanced Game Compatibility

Often called the holy grail of Xbox modding, CPU upgraded consoles have been around for over a decade. However, the CPU upgrade is only half the battle. The other half is getting games to run on the upgraded CPU. This is where StellarOS comes in. StellarOS includes a number of enhancements to the Xbox kernel that greatly improve game compatibility on these systems.

In the past, the only way to get games to run at these faster speeds on a CPU upgraded Xbox was to patch the game executables with very mixed results. Project Stellar takes a different approach. Instead of patching the game executables, Project Stellar handles the issues directly in the kernel.

Project Stellar's approach has a number of advantages over patching the game executables. The first and primary advantage is that compatibility is improved for all games. This means that games that have never worked on a CPU upgraded Xbox will now work. No more patching, video or audio stuttering, or crashing. Just load your game and play.

Extended CPU Microcode Support

Extended CPU microcode support adds support for over 16 different Pentium III CPU models and steppings covering over a hundred different SKUs. This covers all possible CPU upgrades for the original Xbox.

With this feature enabled, on boot, StellarOS will automatically detect the CPU model/stepping and apply the correct and latest microcode update to the CPU.

  • Celeron - Model 06 - Stepping 0, 5, A, and D
  • Celeron - Model 08 - Stepping 1 and 3
  • Intel Celeron M - Model 09 - Stepping 5
  • Intel Pentium M - Model 09 - Stepping 5
  • Pentium III - Model 07 - Stepping 1, 2, and 3
  • Pentium III - Model 08 - Stepping 1, 3, 6, and A
  • Pentium III - Model 0B - Stepping 1
  • Pentium III Xeon - Model 07 - Stepping 1, 2, and 3
  • Pentium III Xeon - Model 08 - Stepping 1 and 3
  • Pentium III Xeon - Model 0A - Stepping 0 and 1

EEPROM Backup Tools

With 1.1.0 two new tools have been added to StellarOS to help backup and restore the Xbox EEPROM. Backing up the EEPROM is a key step in making sure you never lose your Xbox's unique keys.

Improved OLED Error Codes

StellarOS now has improved OLED error codes. These new error codes are more descriptive and help you determine what went wrong.

In the past, a general hardware fault on power-up would result in a system that reboots and flashes red and green. With Project Stellar, we've disabled this behavior and instead display a more descriptive error code on the OLED. We're constantly working toward our database of error codes and their meanings.

For software, it's a bit different. In the past, a software crash would either lock the system up or cause it to reboot. With Project Stellar, we've added a new error code that will display on the OLED. This error code will help us figure out what went wrong and help you get back up and running.

Open Source Contributions

Open source software is very important to us here and contributing back is one of the many ways we like to show our support.

nxdk lvgl LithiumX


  • Added fatal kernel errors readout to OLED.
  • Implemented FATX partition number of clusters check.
  • Implemented legacy partition support.
  • Implemented 'Stellar-Enhanced Game Compatibility'.
  • Implemented 'Extended CPU Microcode Support'.
  • Force HalBootSMCVideoMode if no AV pack is present.
  • Force HalBootSMCVideoMode to HDTV if a XboxHDMI/HD+ is installed.
  • Ignore AV pack interrupts.
  • Disable blocking on no AV pack.
  • Prevent entering safe mode on eject button restart.
  • Added missing reboot system on tray eject logic to XBE loader.
  • Changed IGR to power cycle console.
  • Improved DVD eject logic.
  • Fixed EEPROM decryption failure causing system freezing.
  • Stability improvements for StellarOS settings.
  • Fixed 'Check for Updates' freezing.
  • Implemented hard drive overview information.
  • Implemented hard drive formatting tools.
  • Implemented clear cache partitions tool.
  • Implemented graceful exit from StellarOS.
  • Fix exit freezing when VSYNC is enabled.
  • Implemented dashboard settings for audio and video.
  • Disable FTP server in safe mode.
  • Added extended partition support to FTP server.
  • Fixed grammar mistakes in UI.
  • Implemented EEPROM backup tools.
  • Fixed network initialization failure causing StellarOS to exit.
  • Added repeat input functionality to lvgl input driver.
  • Implemented 'Date and Time' and 'Timezone' settings.
  • Update timezone DST for USA 'Energy Policy Act of 2005'
  • Removed DST for Mexico City.
  • Implement QR code for user manual.
  • Fixed safe mode incorrectly triggering with certain DVD drives.
  • Display "PC MODE" on the OLED screen when connected via WebUSB.
  • Implemented "XCODE STALL" error code.
  • Added additional XboxHD v2 detection logic.
  • Fixed SectorNumber512 calculation in IdeStartReadWrite().
  • Disable HDMI upscaling while in safe mode.
  • Disable native 720P boot animation rendering while in safe mode.
  • Added "Native 720P Rendering" boot animation option.
  • Fixed clock speed on StellarOS Overview page.
  • Changed 'Auto' fan speed label to 'Stock'.
  • Added unique menu icons for Network Devices and XboxHD+.
  • Improved update checker stability.
  • Implemented SHA1 checksum and verification for firmware update installer.
  • Fixed auto fan speed.
  • Prevent eject button safe mode trigger on soft resets.
  • Fixed PFN database not properly resetting causing virtual memory to be unavailable. This should resolve most games failing to boot.
  • Fixed incorrect firmware version displayed on the Help page.
  • Implemented XboxLANKey, XboxSignatureKey, and XboxAlternateSignatureKeys kernel exports. Fixes saved games and various game issues.
  • Fixed bootloader hanging resulting in "black screen on boot" for some 1.6 users.
  • Fixed FTP showing empty directories with WinSCP clients.
  • Improves check for update logic. It should resolve the issue of some systems freezing during the update check.
  • Fixed issues related to saving settings.
  • Fixed incorrect fan speed displayed on the Overview page.
  • Fixed incorrect firmware version displayed on the Check for Updates page.


If you've made it this far then you're probably wondering what's next. The month of May is primarily going to be focused on fully catching up orders and building up inventory.

There's still a lot more to come... See you in the next update!
- Dustin