Files
LithosAnanake/kernel/include/starkernel/console.h
T
rajamesandClaude Opus 5.5 a78cc56c31 fix(v4): nothing of a session left on screen after logout
From the fresh review of the stick's increment 1 (With fixes):
- Critical: after logout Zuse's last screen, her prompt included, could be
  drawn back on a headless machine. The logout clear (ESC[2J) blanked the
  pixels only: Alt+TAB, still read while headless, redrew the terminal
  from its saved text; and if she had Alt+TABbed to the graphics view
  before the pull, the clear did nothing and her session stayed on screen
  (and the console did not draw at her next login). Now vt100_reset()
  forgets everything the terminal has shown -- the on-screen text, the
  scrollback and their boot snapshots -- makes it visible again and fills
  the screen; and Alt+TAB does nothing while the screen is off (v3's never
  is, so v3 is unchanged).
- Important: an EMERGENCY_CONSOLE_ENABLED build no longer clears the screen
  when Zuse's drive is pulled: its console goes on running.

Red: alttab_after_logout 183308 (4515 lit), alttab_before_pull 183529
(4539 lit; the console not redrawn), emergency_pull 183759 (0 lit).
Green: 184115, 184328, 184552; regression 184805-185956 (screens,
keyboard, hotplug, emergency, v3 typed by keyboard) all pass.
Accepted: 190111, 190312, 190710, POST 538/538, dict_hash
0xfec8c47cfc6f437f; test-32, 39 modules, 0 failures.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-26 19:14:22 -04:00

262 lines
10 KiB
C
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
/*
StarForth — Steady-State Virtual Machine Runtime
Copyright (c) 2023–2025 Robert A. James
All rights reserved.
This file is part of the StarForth project.
Licensed under the StarForth License, Version 1.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at:
https://github.com/star.4th@proton.me/StarForth/LICENSE.txt
This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
express or implied, including but not limited to the warranties of
merchantability, fitness for a particular purpose, and noninfringement.
See the License for the specific language governing permissions and
limitations under the License.
StarForth — Steady-State Virtual Machine Runtime
Copyright (c) 2023–2025 Robert A. James
All rights reserved.
This file is part of the StarForth project.
Licensed under the StarForth License, Version 1.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at:
https://github.com/star.4th@proton.me/StarForth/LICENSE.txt
This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
express or implied, including but not limited to the warranties of
merchantability, fitness for a particular purpose, and noninfringement.
See the License for the specific language governing permissions and
limitations under the License.
*/
/**
* console.h - Serial console + framebuffer VT100 interface for StarKernel
*
* Output policy:
* - Serial UART is always active (initialized by console_init).
* - When console_fb_init() has been called and the framebuffer is ready,
* every character is also rendered through the VT100 terminal on screen.
* - Both outputs are always live simultaneously; serial cannot be disabled.
*/
#ifndef STARKERNEL_CONSOLE_H
#define STARKERNEL_CONSOLE_H
#include <stdint.h>
#include <stddef.h>
#include "uefi.h"
/**
* Find the board's serial console line. Must be called before anything is
* printed: until it is, and on a board with no such line, the console writes
* to no serial port and reads from none. On a PC it is COM1, if a UART
* answers there; elsewhere it is the UART the devicetree names as the
* console (/chosen/stdout-path); with no devicetree at all it is the UART of
* QEMU's virt machine. @p dtb may be NULL.
*/
void console_attach_serial(const void *dtb);
/**
* Initialize serial console (UART).
* Must be called once during early kernel boot, after console_attach_serial().
*/
void console_init(void);
/** Print one line saying which serial line the console found, or that there is none. */
void console_describe_serial(void);
/**
* Initialize the framebuffer VT100 terminal.
* Call after UEFI boot services have been exited and the GOP framebuffer
* address is known (from BootInfo). Safe to call with info==NULL (no-op).
* fmt: FB_PIXEL_BGRX32 is correct for most QEMU / real hardware GOP.
*/
#include "framebuffer.h"
void console_fb_init(const FramebufferInfo *info, FbPixelFormat fmt);
/**
* FABRIC-0.md item 4.4j: switch the framebuffer console's glyph backend from
* font_8x16.c to TTF-TEXT's rasterizer. Thin wrapper over
* vt100_enable_ttf() -- see that function's doc comment for the full
* contract (lazy font load, cell-geometry/cols/rows recompute, screen
* clear, one-shot). No-op if the framebuffer console was never
* initialized (console_fb_init() not called, or it no-op'd on a NULL
* framebuffer).
*/
void console_fb_enable_ttf(void);
/* Whether console text is drawn on the framebuffer too (on by default, as
* v3's console has it). The v4 boot turns it off until Zuse logs in, and
* off again when she logs out: "splash only, log on serial"
* (docs/v4.0.0/STICK.md 2). The serial line always has everything. */
void console_fb_mirror(int on);
/* Erase the screen and forget everything the terminal has shown -- the
* on-screen text and the scrollback, so nothing can be drawn back -- and
* leave the terminal visible, cursor home (when the framebuffer is up). */
void console_fb_clear(void);
/**
* FABRIC-0.md item 4.4q: thin wrappers over vt100_scroll_back()/
* vt100_scroll_fwd() -- see those functions' doc comments for the full
* contract. No-op if the framebuffer console was never initialized.
*/
void console_fb_scroll_back(uint32_t n);
void console_fb_scroll_fwd(uint32_t n);
/**
* FABRIC-0.md item 4.4y-revised: thin wrapper over vt100_toggle_graphics()
* -- see that function's doc comment for the full contract (the
* Alt+TAB graphics/text state machine). No-op if the framebuffer console
* was never initialized.
*/
void console_fb_toggle_graphics(void);
/**
* Thin wrapper over vt100_draw_cursor() -- see that function's doc
* comment for the full contract (a static block cursor at the terminal's
* current position). No-op if the framebuffer console was never
* initialized.
*/
void console_fb_draw_cursor(void);
/**
* Thin wrapper over vt100_erase_cursor(). No-op if the framebuffer
* console was never initialized.
*/
void console_fb_erase_cursor(void);
/**
* Write a single character to serial console
*/
void console_putc(char c);
/**
* Write a null-terminated string to serial console
*/
void console_puts(const char *s);
/**
* Write a string with newline to serial console
*/
void console_println(const char *s);
/**
* console_ensure_line_start - Make sure the *next real output* starts at
* the beginning of a fresh output line, closing off whatever is currently
* mid-line (e.g. a dangling prompt). No-op if already at line start.
*
* FABRIC-2.md §I.9 fix, 2026-09-05: the newline is DEFERRED, not emitted
* immediately -- it only actually reaches the console on the next real
* console_putc() call, and is silently dropped (never emitted at all) if
* console_cancel_deferred_line_start() is called first instead. Before this
* fix, an immediate, unconditional newline here meant any caller invoking
* this function "just in case" (sk_repl_idle() being the one real caller)
* would visibly snap a bare, unfinished prompt line to a fresh blank line
* even when nothing was actually about to be printed -- indistinguishable
* from Enter having already been pressed at that prompt. Deferring means a
* caller that turns out to have nothing to print can cancel cleanly, with
* zero visible effect, while a caller that does print gets the correct
* "close the old line first" behavior for free, still counted by
* console_tx_count() as real output (unlike the old always-silent inner
* form) since it is realized through the normal console_putc() path.
*/
void console_ensure_line_start(void);
/**
* console_cancel_deferred_line_start - Discard a pending deferred newline
* from console_ensure_line_start() without ever emitting it. No-op if no
* newline is currently deferred. Callers that speculatively deferred a line
* break before checking whether they actually have anything to print
* (sk_repl_idle()'s idle-beat check being the motivating case, FABRIC-2.md
* §I.9) call this when the check comes back negative, so the console is
* left exactly as it was -- no stray newline, no phantom blank line.
*/
void console_cancel_deferred_line_start(void);
/**
* console_tx_count - Monotonic count of console_putc() calls delivered to
* either output (serial and/or framebuffer). In use by the REPL to detect
* that an idle bottom half (heartbeat, USB attach/detach) wrote to the
* console while the top-level prompt was showing, so it can re-anchor the
* prompt afterward. Never decreases.
*/
uint64_t console_tx_count(void);
/**
* Read a single character from serial console (non-blocking)
* Returns -1 if no character available
*/
int console_getc(void);
/**
* Check if character is available for reading
*/
int console_poll(void);
/**
* Set the active VM name shown as [Name] prefix on each output line.
* Pass NULL to suppress the prefix (kernel-only output before any VM).
* Copies into internal storage (FABRIC-2.md Phase F, 2026-08-28) -- the
* caller's own pointer does not need to remain valid afterward.
*/
void console_set_vm_name(const char *name);
const char *console_get_vm_name(void);
/**
* console_save_vm_name - Copy the current active-VM name into the
* caller's own buffer, for a later console_set_vm_name() restore.
*
* console_get_vm_name() alone is NOT safe for save-then-restore: it
* returns a pointer into the single internal buffer console_set_vm_name()
* copies into, so an intervening console_set_vm_name() call (the normal
* "switch, do work, switch back" pattern every BIRTH/VM-EXEC/CONNECT-*
* call site uses) overwrites the very bytes the saved pointer points at
* before the restore ever runs -- found live 2026-08-28, the restore
* silently no-ops. Copies at most cap-1 bytes plus a NUL terminator;
* writes "" if there was no active name (NULL) to save.
*
* @param out Caller-owned buffer.
* @param cap Its size in bytes.
*/
void console_save_vm_name(char *out, size_t cap);
/**
* FABRIC-3.md SXXV follow-up (2026-09-13): the line prefix used to be a
* bare "[VMName] ", ambiguous between a console-proxy VM and the actual
* identity VM behind it (e.g. "rajames" the console vs. "rajames~user"
* the real WIREBIND-restricted identity) -- confirmed live to cause real
* confusion during testing. Unified to "[user@VMName] " when a user
* context is available, still "[VMName] " when not (unauthenticated/
* pre-login, unchanged from today).
*
* console.c is a clean HAL module with no dependency on capsule/WIREBIND
* logic (zuse_session, capsule_wirebind_attached_username()) -- pulling
* either in directly here would be a real layering violation, not just a
* style preference. This callback lets repl.c (which already computes
* exactly this for sk_print_prompt()) supply the "user" half without
* console.c knowing anything about VMs, sessions, or WIREBIND. Returns
* NULL/empty for "no user context" (falls back to the bare "[VMName] "
* form); the returned pointer must remain valid until the next call
* (matches console_get_vm_name()'s own single-buffer convention).
*/
typedef const char *(*console_user_prefix_fn)(void);
void console_set_user_prefix_provider(console_user_prefix_fn fn);
/* Last FORTH word name set by the dispatcher before entry->func(vm).
* Printed by the #GP fault handler to identify the faulting word. */
extern volatile const char *g_sk_fault_word;
#endif /* STARKERNEL_CONSOLE_H */