The project CSMWrap 3.0 has recently been released, aiming to develop an EFI application for booting systems that only support legacy BIOS platforms in modern UEFI-based environments. CSMWrap achieves this by recreating the BIOS environment on UEFI (class 3) systems, packaging the SeaBIOS assembly as a CSM (Compatibility Support Module) module and running it as an external EFI application. The project is written in C language and distributed under the LGPL-2.1 license.
CSMWrap offers 64- and 32-bit assemblies of EFI applications, which can be easily placed in the /EFI/BOOT/ directory in the FAT file system section on media with an operating system that can only boot in BIOS environments. UEFI firmware will then recognize this media as a boot device. It is recommended to use partition tables in MBR format on the boot device.
The latest CSMWrap 3.0 branch has added support for the csmwrap.ini configuration file, which can be placed in the same directory as the EFI executable to specify additional settings. Users can now customize parameters such as the serial port for debug output, the path to an alternative VGABIOS, the PCI address of the video card, flags for disabling IOMMU, and suppressing the display of extra information about the operation of CSMWrap, in addition to the banner and error messages.