Imported from GitHub: DartFrogTek/PCIe-PCI-ISA · commit b254086 · license MIT

Description

Potential PCIe-to-PCI-to-ISA pathway.

README

Potential PCIe to PCI to ISA BUS pathway.

This repository contains information and files on how to potentially provide modern systems with an ISA bus including ISA DMA.

More information is available on the "dISAppointment - LPC to ISA adapter - ISA on modern motherboard" thread.

https://www.vogons.org/viewtopic.php?t=93291

## PCIe support is likely a bust without custom address translation and software modification. https://dn720003.ca.archive.org/0/items/33.-oxford-legacy-address-ranges/33.Oxford_Legacy_Address_Ranges.pdf See page 40 of Vogons.

## PCIe support likely requires custom address translation / software assistance Early testing suggests PCIe-to-PCI-to-ISA is not a transparent drop-in path for legacy ISA DMA. Some PCI/config or I/O traffic can reach the IT8888 through a PCIe-to-PCI bridge on a Z390/Windows 10 system, but other accesses appear not to reach the chip. ISA DMA likely requires a software layer that acts as a virtual 8237/DDMA master, programs the IT8888 DDMA slave, and uses controlled DMA-safe buffers or otherwise verified bus-master-accessible addresses.

I am currently trying to look into getting source/reverse engineering the vdma8.exe from KYA on vogons to pursue this further. Go here to see current progress we have real data from a PicoGus through the entire chain! https://www.vogons.org/viewtopic.php?t=111221

IT8888 based ISA8888 PCI to ISA Card

• This card/breakout board should allow a user-provided ISA Card to be translated into a PCI card via IT8888.
• ISA DMA is facilitated by PCI bus mastering through the IT8888 chip.
• Project is in KiCAD format.
• WIP

ACPI SSDT

• A way to configure motherboard bus bridges to allow I/O forwarding.
• Boilerplate implementation, given to me by an absolute legend.
• Added steps on how to find bridge and modify IT8893_ACPI_SSDT.asl for compiling.
• IT8893_ACPI_SSDT.asl Compiles UNTESTED - DO NOT USE

DXE Driver

• Last resort, given to me by an absolute legend.
• Boilerplate implementation

GRUB

• It's possible to configure PCI bridges using GRUB, avoiding the need for DXE Drivers or ACPI SSDT.
• Requires GRUB and potentially turning off secure boot.

CHIPSEC

• Various LPC DMA tests with CHIPSEC
• Scripts get placed in 'chipsec-1.13.11\chipsec\modules\common'
• Tests are ran with:
  • "python chipsec_main.py -m common.lpc_dma_check"
  • "python chipsec_main.py -m common.lpc_dma_z390_test"
  • "python chipsec_main.py -m common.lpc_dma_h81_z390_test"
• Tests work, but might crash your system.

Extras

• Datasheets, Documents, Pin Mappings.

Thanks

• Everyone at Vogons, seriously thanks.
• Absolute Legend #1, #2, and #3. [Names redacted to protect their jobs]
• My wife.

Without my wife, everyone at Vogons, and the legends, none of this would likely exist.