SchOS/boot/uefi
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Nexoniarz c79b1d6d6d boot menu: turn the touchpad driver off, and trace its steps
The ASUS TUF A15 freezes at the default resolution shortly after the
loader hands over -- screen dark, Caps Lock dead -- and it is the only
machine here with an I2C-HID touchpad, which the driver added in the same
release now probes at boot. "Touchpad driver: on/off" in the F8 menu
answers whether it is the cause on the machine itself, through a new
SCHBOOT_OFF_FLAGS byte the kernel checks before starting the driver.

A verbose boot now prints each step of the probe before taking it, so if it
is the cause, the last line on the screen says which step.

Also: S in the menu wrapped at five entries whatever the count.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S1giNvrHTrPMPw7V6x1kQ4
2026-10-24 23:33:25 +02:00
..
efi.h display: a 64-bit framebuffer address, no mirroring onto itself 2026-10-23 15:46:42 +02:00
main.c boot menu: turn the touchpad driver off, and trace its steps 2026-10-24 23:33:25 +02:00
README.md licence: SchOS is GPL-2.0-or-later, no longer Apache-2.0 2026-10-22 08:48:45 +02:00
startup.nsh boot/uefi: a working UEFI loader, with one known limitation 2026-08-09 17:13:09 +02:00

UEFI loader

The loader. This directory once existed only so the BIOS path could be moved into boot/bios/ without pretending the split was hypothetical; it is now the only path there is.

See ../README.md for the hand-off contract a loader has to satisfy. The short version: the kernel wants long mode with paging on, its ELF segments placed, a 24-byte-entry E820-shaped memory map, and framebuffer geometry — and it does not care which firmware produced them.

What this will need, in rough order:

  1. A PE/COFF target. clang can emit one directly (--target=x86_64-unknown-windows -fuse-ld=lld-link), so no new toolchain: the same LLVM install already builds every other target here.
  2. The handful of UEFI structures actually used — the system table, boot services, LOADED_IMAGE, SIMPLE_FILE_SYSTEM, GRAPHICS_OUTPUT. Written from the specification rather than by importing gnu-efi or EDK II, which is both a licence question and a large dependency for something this small.
  3. GetMemoryMap translated into the same 24-byte entries e820.c already parses. Not a second format for the kernel to learn.
  4. ExitBootServices before touching the memory it described.
  5. Graphics Output Protocol for the framebuffer, filling the same VBE_INFO_ADDR structure the kernel reads.

The image goes at EFI/BOOT/BOOTX64.EFI on a FAT ESP, which also means the ISO carries a single El Torito EFI entry.