| Filename | Latest commit message | Latest commit date |
|---|---|---|
9ab8a7a426
Two things.
**The F8 resolution now applies to the other displays as well.** It already
reached them once vgpud started -- that was the last commit but one -- but not
before: choosing 1024x768 changed the screen it was chosen on and left the
other at 1280x800, so the menu and then the splash appeared on it as a small
rectangle in the middle of a larger black one. Which is a fair reading of "the
resolution change is not changing resolution".
The resolution offered in that menu is a statement about the machine's display,
not about one adapter of it, so both stages before vgpud now follow it:
the loader mirrors_match() puts every mirror GOP into the primary's mode,
called from mirrors_show() so it cannot be forgotten at a new
call site. Two integer comparisons in the common case.
the kernel setup_scanout() takes gfx's dimensions over GET_DISPLAY_INFO's.
Same argument as vgpud's bring_up(): the host window's size is
a fact about QEMU, and the console's mode is the one somebody
chose.
**And the greeting is no longer a race.** "Welcome to SchOS!" was printed after
every job had been started, including the shell on the console -- so which of
the two reached the screen first was up to the scheduler, and it went both ways
about evenly. A boot that sometimes greets you above the prompt and sometimes
below it does not read as two orderings of one boot; it reads as a line printed
by mistake.
schinitd now holds back the job that owns the console -- `own_tty`, which is
exactly the job whose output lands there -- until after the greeting is
written. That is enough to settle it: this process writes the line, and only
then asks PID 1 to spawn the shell, so the fork has not happened yet. Nothing
waits on it that was not already waiting.
Verified: F8 -> Resolution -> 1024x768 -> boot, with the virtio head
screendumped over QMP at three points during startup and once at the prompt --
1024x768 throughout, and byte-identical to the stdvga head. Three consecutive
boots put the greeting at the same offset, ahead of the prompt every time.
Both supported configurations: one boot each, no traps, no panics, socktest and
memfdtest green.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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| .. | ||
| efi.h | ||
| main.c | ||
| README.md | ||
| startup.nsh | ||
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:
- 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. - 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. GetMemoryMaptranslated into the same 24-byte entriese820.calready parses. Not a second format for the kernel to learn.ExitBootServicesbefore touching the memory it described.- Graphics Output Protocol for the framebuffer, filling the same
VBE_INFO_ADDRstructure 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.