cb9b06d46f
A panic no longer ends in a picture. The report is drawn as before, and
then GMMOS runs under it: the real kernel stays dead -- the other
processors are halted, and nothing of it is called that locks, sleeps,
allocates or waits for an interrupt -- and GMMOS keeps its own clock
(the TSC), its own keyboard (micro drivers, polled), and the screen.
On the report: a live status line counting down the three-minute
power-off, which any key cancels, and the keys.
Space the last 300 lines of this boot's log as QR codes, a page per
symbol, numbered; + and - trade module size for capacity
L the log on screen, scrolled
T a terminal: why, log, grep, ps, cpus, pci, mem (page tables
walked first, so a bad address cannot fault), uptime, restart,
poweroff
R R restart; P P power off -- twice, so a stray key does neither
The first micro driver is PS/2, polled: kbd.c with everything but the
keys taken out. The probe asks the keyboard to echo, so a controller
with nothing behind it is not offered as one. Polling also sidesteps the
IRQ 1 polarity quirk, which is about interrupt routing.
A panic inside GMMOS (or a second one in the report) is reported and
then only blinks; it does not re-enter GMMOS.
Checked under QEMU: every screen; two QR pages read off a screenshot
with zbar decode to the log text exactly; restart reboots; left alone it
still powers off at three minutes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S1giNvrHTrPMPw7V6x1kQ4
38 lines
1.5 KiB
C
38 lines
1.5 KiB
C
#pragma once
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#include "core/types.h"
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// GMMOS -- Guru Meditation Micro OS. What runs after a panic.
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//
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// The PSOGM used to be the last thing the kernel did: a report, blinking
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// keyboard lights, and a machine that needed its power button. GMMOS keeps the
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// report and goes on living under it. The real kernel is dead and stays dead --
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// every other processor is halted (see trap()), and nothing of it is called
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// again that takes a lock, sleeps, allocates or waits for an interrupt. What
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// GMMOS has instead is its own: the framebuffer, a clock read from the TSC, and
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// keyboards it polls itself through micro drivers.
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//
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// A micro driver is a cut-down copy of a real one that does only what a
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// keyboard needs. The real drivers run on interrupts, threads and locks, all of
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// which belong to the kernel that just died.
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//
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// See kernel/gmmos/gmmos.c.
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void gmmos_run(char *reason, addr_t *pcs, int npcs) __attribute__((noreturn));
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// One keyboard GMMOS can read by polling.
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struct gmmos_kbd {
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const char *name;
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int (*probe)(void); // nonzero if it is there and usable
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// The next key, or 0 when there is none: a Unicode codepoint, or one of the
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// KBD_* codes from include/dev/kbd.h for keys that are not characters.
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int (*poll)(void);
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void (*leds)(int on); // optional: all three lights on or off
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};
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extern const struct gmmos_kbd gmmos_ps2;
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// From kernel/core/panic.c: draw the report again, and where its closing
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// lines are, which GMMOS writes its status and its keys into.
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void psogm_repaint(void);
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void psogm_footer(int *x, int *y, int *step);
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