Install Windows Xp On Uefi System Here

Hi all,

I'm using ST's CubeMX implementation on a F4 discovery board. I use ST's USB middlewares with FreeRTOS.

When I get a special OutputReport from PC side I have to answer nearly immediately (in 10-15 ms). Currently I cannot achieve this timing and it seems my high priority tasks can interrupt the USB callback. What do you think, is it possible? Because it's generated code I'm not sure but can I increase the priority of the USB interrupt (if there is any)?

Thank you, David

10 to 15 ms is very slow, so I'm sure its possible.

Where is the USB callback function called from? If it is an interrupt then it cannot be interrupted by high priority RTOS tasks. Any non interrupt code (whether you are using an RTOS or not) can only run if no interrupts are running.

Without knowing the control flow in your application its hard to know what to suggest. How is the OutputReport communicated to you? By an interrupt, a message from another task, or some other way?

The callback which receive the data from PC is called from the OTGFSIRQHandler (it's the part of the HALPCDIRQHandler function). I think the problem is SysTickHandler's priority is higher than OTGFSIRQHandler and it's cannot be modified, but the scheduler shouldn't interrupt the OTGFSIRQHandler with any task handled by the scheduler. Am I wrong that the scheduler can interrupt the OTGFS_IRQHandler?

: XP has no native support for USB 3.0/3.1 controllers, meaning your mouse and keyboard might stop working the moment the installer starts. Win-Raid Forum Practical "Cheat Codes"

Windows XP does not recognize modern ACPI (Advanced Configuration and Power Interface) tables, resulting in immediate STOP: 0x000000A5 blue screens.

If using a pure UEFI system, write the drive, and then manually apply a tool like or FlashBoot . These tools place an alternative bootmgfw.efi file onto the EFI partition of the USB drive, which injects standard 16-bit video interrupts into memory before handing off control to the Windows XP setup engine ( SETUPLDR.BIN ). Phase 5: Executing the Installation

Modern GPUs (Nvidia RTX, AMD Radeon RX, Intel Iris/Arc) do not have Windows XP drivers. The system will operate using a generic VESA frame buffer, which limits display resolution and hardware acceleration. Community-made VBEMP (Universal Video Driver) or modified drivers from backporters can sometimes provide higher resolution options.

If you prefer free tools, you can use Rufus to create a standard bootable USB, then manually apply . This tool mimics a legacy VGA BIOS (INT 10h handler), which Windows XP requires during its initial boot phase.

Turn off Fast Boot to force the motherboard to initialize all legacy hardware parameters during power-on self-test (POST). Phase 4: Writing the USB Installer with UEFI Emulation

Windows XP does not include native drivers for NVMe SSDs, AHCI (without F6 floppy injection), or UEFI RAID controllers. The default IDE emulation mode is absent on most post-2015 chipsets.

Open Rufus, select your ISO, and set the partition scheme to and Target System to BIOS (or UEFI-CSM) . Click start.

Modern systems use AHCI or NVMe, which XP does not natively support. You will need to find the specific SATA/AHCI drivers for your motherboard chipset and inject them. UEFI System: A motherboard with UEFI capabilities. Phase 1: Preparing the UEFI-Compatible USB Drive

FlashBoot will automatically include a UEFI loader, a virtual VGA BIOS wrapper, and necessary partition tweaks. Click . Method B: Manual Preparation via UefiSeven

Because Class 3 UEFI firmware cannot execute 16-bit real-mode BIOS code, you must wrap the installation with a UEFI loader.

: A clean, official image (preferably 32-bit for maximum driver compatibility).

Modern websites will not load due to outdated SSL/TLS certificates. Graphics: Lack of graphics drivers means poor performance. Summary of Alternatives

Select your USB drive. If options exist, select the non-UEFI prefix first; if that fails, try the UEFI-targeted flash drive option.

Before you begin, you must understand the hardware walls you will hit:

: UEFI Secure Boot must be disabled to allow legacy operating systems to boot.

Thank you for the answer, I think I'm a bit confused with the Cortex ISR priorities :-) What I can observe is if I use a much higher osDelay in my high priority task I can respond for the received USB message much faster. This is why I think tasks can mess up with my OTG interrupt.