/applesi-paging-demo

Demonstrating 4K vs 16K paging on Apple Silicon Macs

Primary LanguageC

Apple Silicon 4K vs 16K Paging Demo

A simple bare metal test to run on Apple Silicon Macs that sets up identity paging in the lower half (TTBR0) using either 4K or 16K page sizes.

Requirements:

  • aarch64-elf-gcc cross compiler (brew install aarch64-elf-gcc)
  • macvdmtool (plus a USB SuperSpeed cable) to view serial output on real hardware

Tested Environments

4K (1GB blocks) 4K (2MB blocks) 16K
VMAPPLE on M1 Pro ✅ ✅ ✅
M1 Bare Metal ❌ ✅ ✅
M4 Bare Metal ❌ ✅ ✅

Bare metal systems don't seem to like 1GB blocks, but are fine with 2MB ones.

Setup

First, pick your mode (4k or 16k page sizes) in config.h. Then, make sure your serial port is correct for your platform in serial.h.

Finally, follow these steps to build and run:

  1. make
  2. Copy demo.bin somewhere you can access it in 1TR / your VM
  3. Boot into 1TR and downgrade to permissive security
  4. Install this with kmutil configure-boot -v /Volumes/[YOUR VOLUME] -c demo.bin -r --entry-point 0 --lowest-virtual-address 0
  5. Use macvdmtool or watch your VM's serial port to see output