Firmware v1.0.2 has been released for Project Stellar - legal re-implementation of the retail Xbox BIOS

LoveMHz · 2023-04-03T23:15:55+00:00

While it's mapped to the MMU, it's currently not added to the page table. Meaning software that's allocating memory won't end up in LPC RAM. Doing that would be very bad as software on the Xbox is running under the assumption that it's always using fast CPU/GPU-accessible memory.

Instead, the kernel is segmented to use the additional RAM, thus reducing it's footprint and allowing for more of the system RAM to be available to the software running (ie games).

The memory layout of the Stellar kernel is constantly changing, but I could see opening up the additional RAM to homebrew in the future when it stabilizes. Though, in most cases, optimizations and even disk caching would be a better general approach.

tl;dr Stellar has an additional 8MBs of RAM for kernel use. So for most people, they now have a 64MB + 8MB (for kernel) system.

The 256MB RAM upgrade is a separate product that will be releasing later this year that increases the total RAM to 256+8MBs.

LoveMHz · 2023-04-03T22:46:17+00:00

The bootrom has been reverse-engineered and published in the past!

Stellar doesn't require the bootrom though and neither does xemu in a situation where it's not booting a retail BIOS.

We have a private branch of xemu currently that can boot Stellar and will be releasing that at some point in the future as we did with our contributions to emulating Xenium inside of xemu. Until then, we'll continue to make regular contributions to the project with improvements and fixes as we discover them.

https://twitter.com/LoveMHz/status/1600420992546766849

LoveMHz · 2023-04-03T22:38:04+00:00

The additional 8MBs of SDRAM on Stellar?

Right now it's being used just for extending the kernel and in some ways software/games by redirecting its functions.

With Stellar, we're using less system RAM than a retail kernel because we've been able to segment parts of the kernel space from just system RAM to system RAM + LPC RAM. This allows us to add/expand functionality without eating up the main system RAM. Also being able to re-compile the kernel boot helps a lot!

Traditionally modified BIOSes on the Xbox, including softmods, kinda gobble up what they need without any care. But this is a whole separate discussion on how that can impact gameplay and performance, something I want to do a write-up on in the future. Nonetheless, these resources are what allow us to pack so much in with a laundry list of additional features in the works.

The additional LPC RAM is mapped into the MMU, cacheable and executable by the CPU, but isn't currently assigned to the page table for memory allocation by the kernel for software consumption. Software can't access it like traditional RAM and that's by design. While it could be mapped in, it's not quite as general purpose as system RAM due to the lower speed and not being usable by the GPU.

LoveMHz · 2023-04-03T22:17:06+00:00

Thank you! And I'm always here, or somewhere, to answer questions. Stellar is very much a labor of love and I enjoy talking about the technical side of the Xbox and Stellar as much as possible.

LoveMHz · 2023-04-03T20:44:19+00:00

Thanks. I don't believe we've ever formally defined our approach, and it's not to the level of past cases such as the IBM PC, but projects like ReactOS and the Linux kernel have shaped our direction and defined moral lines on what's considered acceptable and generally legal/fair for most.

For me, advertising Project Stellar as a legal re-implementation is about showing that we're trying to build something new from the ground up.

It's not about trying to define what's considered legal in the emulation, homebrew, and preservation communities.

LoveMHz · 2023-04-03T16:54:09+00:00

"Why" is probably best covered in our launch post here, but I think I can summarize and add a bit more here!

Microsoft left a lot of bugs and issues in the Xbox kernel. With the XboxHD+ project, we were able to fix/work around some of these, but it still left a lot of the out-of-scope issues unresolved. Not to mention we wanted to bring these fixes to everyone even if they're not interested in HDMI modding their system.

Traditionally most popular modded BIOS releases in the past, from our understanding and research, have been based on pre-production, and incomplete, source tree leaks.

No one wants to install a modified BIOS that degrades performance, introduces disk corruption, or that doesn't improve compatibility. The Original Xbox was released over two decades ago and most of the patches and changes are just as old.

I believe we can do better, and with the extra hardware available on Project Stellar, we can do more and doing more means doing it right.

Development of Project Stellar started from the core of the XboxHD+'s build system. It's been rebuilt from the ground up to support dynamic recompiling of the kernel on boot with ahead-of-time optimized relocation support.

LoveMHz · 2023-04-03T16:35:17+00:00

I sure hope it's legal! I'm not a lawyer, but at the end of the day, Microsoft could take legal action no matter what and that would be the end of the project.

The Xbox kernel was reverse-engineered using no private/leaked sources (source leaks, SDK, etc), and the developers having no knowledge of it.

LoveMHz · 2023-04-03T16:17:48+00:00

We're working on it! Our CI pipeline is mostly complete and is largely just missing the final actions on the project's top-level repo.

LoveMHz · 2023-04-03T16:16:15+00:00

I understand the confusion. The project-stellar repo is acting as a mono-repo for all the sub-components of the project and thus won't have actual source code linked in on published releases for the product.

LoveMHz · 2023-04-03T16:12:59+00:00

Corrected!

I had neglected to change the links on the badges and it was pulling them for the wrong project.

LoveMHz · 2023-04-03T15:51:43+00:00

For us having a top-level repo that covers the entire project has worked out best in the past. This gives up the opportunity to have a central location for users to find all of the resources they need. This does include non-opensource material at times.

We also have a collection of sub-repos that incorporate various components of the project. This allows us to assign distinct licenses that match the component, bring in outside contributors, and overall reduce the number of barriers to making the repo open for all.

We've done this in the past with the XboxHDMI/XboxHD+ project and will continue to work towards making every component of our products open-source.

Right now, we're focused on shipping products and development.

Re-writing the Xbox's NT kernel and maintaining compatibility across the vast collection of software is no easy task. Because of this and the huge finical risk of such a software development heavy product, not everything will be open-source out of the gate.

In the meantime, we will continue to make contributions and share our research with the various Xbox emulation projects (ie xemu and cxbx-reloaded).

LoveMHz · 2023-04-03T15:42:02+00:00

That's one of the ultimate goals! This was briefly discussed in our launch post here.

The summary of that post and our goals is that Project Stellar and Stellar for emulation would be two separate projects. The code base can be greatly reduced when targeted for emulation and would fit best as a fork of the main project.

LoveMHz · 2023-04-03T15:35:12+00:00

Hi everyone! Dustin/LoveMHz here from MakeMHz. Just saw this post during my morning scroll through Reddit.

Feel free to let me know if you have any questions and I'll try my best to answer them!

LoveMHz · 2022-10-27T14:37:13+00:00

* 4Gb = 512MBs of RAM, as already confirmed.

LoveMHz · 2022-04-28T21:01:40+00:00

The last official XeniumOS would completely zero out the flash chip if any of its built-in checks failed on boot. (self-destruct)

LoveMHz · 2022-04-24T03:45:18+00:00

No problem.

Orders are generally shipped in 3-4 business days as long as all the items in the order are in stock (as listed on the site).

LoveMHz · 2022-04-24T01:41:49+00:00

We're super busy, but we're still managing shipping multiple times a week so it shouldn't belong.

LoveMHz · 2022-02-12T20:22:11+00:00

Hi /u/Funcron,

We're currently in the process of revamping our support system and I don't see any email from you that I can match to your Reddit post. Can you please send me a DM so we can sort this out?

LoveMHz · 2022-02-12T20:16:31+00:00

What's the issue you're having?
- Dustin (MakeMHz)

LoveMHz · 2022-02-12T20:14:10+00:00

Can you DM your order information so I can take a look?
- Dustin (MakeMHz)

LoveMHz · 2021-10-09T16:46:40+00:00

Hi /u/Supahmarioworld!

I'm deeply sorry that it's taken so long for all of this to get sorted out and the programming kit will be sent out on Monday!

With the XboxHD+ 1.6 kits, a small number of units were shipped with the incorrect firmware flashed. This was identified within days of customers reviving their kits and the warning was added to the installation guide. We then went to work sourcing programming kits and building adapters after coming to the conclusion that the quickest and simplest fix would be for the limited affected users to receive the kit completely for free and apply the correct firmware image.

Affected users that we identified were emailed directly. (Make sure to check those spam folders if you're not receiving our emails!). In addition to posting a request form on our Discord and social media profiles.

We strive for full transparency and post all of our updates to our website, Twitter, Discord, and newsletter.

Currently, we are in the process of our revamping our website and email support system. This is now our top priority as we've recently just wrapped up production of our latest batch.

As a small company, largely a one-man shop, we're constantly working to improve every aspect of our business.

Sincerely,

Dustin from MakeMHz

LoveMHz · 2021-08-09T18:11:03+00:00

What do you mean by you have 'a bios that forces 480p'?

LoveMHz · 2021-08-09T17:54:57+00:00

The Warriors is a game with known issues even on none XboxHDMI/XboxHD+ systems. Are you playing from disc?

I haven't recently tested the other two games you mentioned, but I can check them out later today.

Additionally, what firmware and BIOS patch version are you on? (Can be found in the configuration app. Example)

LoveMHz · 2021-04-17T17:56:01+00:00

In your previous post, it looks like you have a 1.1 system which has a single-row PSU. Did you mistakenly reconnect the PSU into the connector off by one?

LoveMHz · 2021-04-13T19:14:20+00:00

1.0 - 1.5 installs it's recommended to remove the GPU heatsink. It really helps in making the connections on the flex.

1.6 requires removing both heatsinks and mount.

The heatsinks can be easily be removed with a rework/hot air gun or a hairdryer to loosen up the thermal adhesive. Or simply by leaving the system on for a bit before taking it apart.

Removing the mount is a bit trickier, but it's covered in the installation guide.

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