device: 0.784
architecture: 0.784
boot: 0.732
virtual: 0.630
vnc: 0.609
ppc: 0.538
performance: 0.534
register: 0.529
semantic: 0.518
kernel: 0.507
peripherals: 0.488
socket: 0.485
network: 0.461
files: 0.427
PID: 0.416
x86: 0.380
risc-v: 0.364
VMM: 0.314
hypervisor: 0.283
permissions: 0.271
TCG: 0.249
debug: 0.236
arm: 0.159
graphic: 0.151
assembly: 0.151
KVM: 0.148
i386: 0.128
user-level: 0.119
mistranslation: 0.083

"rc4030: invalid read at 0xf0-0xf8" shows up, then NT MIPS bluescreens
Description of problem:
The problem is fairly nondescript, but it seems to be a chipset regression that popped up between QEMU 8 and QEMU 9. I had a Windows NT 4 VM that I tried booting in the latest QEMU update after a while of not using it, and it just flat-out refused to do that, outputting the ``INACCESSIBLE_BOOT_DEVICE`` error. Any attempt to boot from the hard drive or reinstall the OS from the CD image would return the same bluescreen, and would show the very message shown in the title in the process log.
Steps to reproduce:
1. Download a Windows NT 3.5x/4.0 ISO.
2. Create a disk image ≤2GB in size.
3. Enter the command above.
4. Go through the preparatory setup, as described in [here](https://computernewb.com/wiki/QEMU/Guests/Windows_NT_3.x-4.0_(MIPS)). (ignore the networking switches, or replace ``dp83932`` with ``ne2k_isa``)
5. Launch the installer by running ``cd:\mips\setupldr``.
Additional information:
![exhibit A; shows the 0x0000007b bugcheck output](/uploads/389e7b5fe77e259c6f3b2a703945df73/Screenshot_from_2024-07-28_18-44-15.png)