Tag Archives: mbr

Arca Noae announces GUID for OS/2 Type 1 GPT partitions

In our last post concerning GPT in ArcaOS, we discussed the first phase of support and how our specification allows for multiple partitions up to 2TB in size. As every GUID (Globally Unique Identifier) partition type requires a GUID, we have set:

90B6FF38-B98F-4358-A21F-48F35B4A8AD3

as the GUID for OS/2 Type 1 partitions.

Any GPT partition using this GUID should ultimately be recognizable by any GPT-aware operating system as belonging to ArcaOS.

Although this is now just a simple proclamation, it is, in point of fact, a major advancement for the platform, and sets the stage for our initial GPT support, currently planned for release with ArcaOS 5.1 in 2021.

Arca Noae makes no guaranty as to availability of GPT support for ArcaOS 5.1. When available, GPT support will be an ArcaOS feature only, with no plans to make the technology available for other OS/2 distributions.

Don’t have ArcaOS yet? Now is a great time to pick up a license or two and replace those aging Warp 4 or eComStation installations and get to know what’s new and improved. If you’ve never run OS/2 before, you’ll be amazed. If you last used OS/2 in the 1990’s, you’ll be even more amazed. ArcaOS runs the vast majority of existing OS/2 Warp 4 software, because it really is OS/2 – just better. ArcaOS supports more modern hardware than any other OS/2 distribution available today, making hardware upgrades much easier than ever before. An ArcaOS 5.0 license now means steep discounts on future upgrades, including 5.1.

Arca Noae’s plan for supporting GPT disk layouts in ArcaOS

Through the release of ArcaOS 5.0.6, all OS/2 distributions have only supported MBR (Master Boot Record) partitioning schemes, that is, up to four partitions on a disk, with the possibility of creating multiple logical volumes in one extended partition. This partitioning scheme is also limited to a maximum of 2TB per disk.

The GPT (GUID Partition Table) breaks out of these restrictions by supporting an almost unlimited number of partitions (without the need for logical volumes) and disks exceeding 2TB.

Supporting GPT is another major step for multiboot configurations where the disk has already been partitioned using this style, which will allow ArcaOS to install alongside other GPT-aware operating systems (Windows 10, modern Linux distros, etc.), without the need to install a second MBR-partitioned disk or to wipe, re-partition, and reformat all volumes on the existing disk.

Arca Noae’s approach to supporting GPT will be multi-phased, with the first phase of development currently underway and anticipated for release with ArcaOS 5.1. The design specification of our initial GPT support is to allow for partitions up to the current 2TB maximum size, with multiple partitions of this size possible on disks larger than 2TB. Our specification further provides that ArcaOS be able to create, delete, and modify GPT partitions which are identified by their GUIDs as being “OS/2-type” partitions, and lastly, that GPT support be available for both traditional BIOS (for data volumes) and UEFI-based systems (for boot and data volumes).

Arca Noae makes no guaranty as to availability of GPT support for ArcaOS 5.1. When available, GPT support will be an ArcaOS feature only, with no plans to make the technology available for other OS/2 distributions.

Don’t have ArcaOS yet? Now is a great time to pick up a license or two and replace those aging Warp 4 or eComStation installations and get to know what’s new and improved. If you’ve never run OS/2 before, you’ll be amazed. If you last used OS/2 in the 1990’s, you’ll be even more amazed. ArcaOS runs the vast majority of existing OS/2 Warp 4 software, because it really is OS/2 – just better. ArcaOS supports more modern hardware than any other OS/2 distribution available today, making hardware upgrades much easier than ever before. An ArcaOS 5.0 license now means steep discounts on future upgrades, including 5.1.

Arca Noae progress report: ArcaOS on UEFI-only hardware

Unified Extensible Firmware Interface (UEFI) is gradually replacing the traditional system BIOS. The vast majority of PCs on the market are now based on UEFI technology, and a number of these include what is called a Compatibility Support Module (CSM). This CSM “layer” replaces the traditional BIOS and provides backward-compatibility support for booting operating systems such as DOS, OS/2, and, of course, ArcaOS. (This is typically listed as “Compatibility”, or “Legacy” boot in the system setup menu of UEFI-based PCs.)

PC manufacturers and Intel specifically have stated publicly that they intend to phase out inclusion of a CSM layer in the next few years (in the case of Intel, beginning in 2020), leaving UEFI as the only boot option, eliminating the “Compatibility” selection. To prepare for this, Arca Noae has been exploring ways to boot ArcaOS on systems lacking a manufacturer-supplied CSM. We are pleased to announce that over the last several months our development team has made significant progress in achieving that goal.

In the lab, we are now able to boot ArcaOS all the way to a desktop on a system configured to boot in UEFI mode. All necessary drivers load, with all CPU cores running, and ArcaOS properly switches to graphics mode. The importance of this accomplishment cannot be overstated. To our knowledge, this is the first time ArcaOS has ever booted without the presence of an active CSM.

Having said that, this project is still in its research stage and not yet ready for release to our beta testers. Native UEFI support requires changes to the low level disk and video subsystems, and this work is ongoing.

We remain cautiously optimistic that we will complete our Proof of Concept successfully and will have a UEFI solution for a future ArcaOS version.

Oh, and Arca Noae has been an Adopting member of the UEFI Forum since 2015.