From cc5c971c3cc498d528a2f74f4dc2f8e27a690311 Mon Sep 17 00:00:00 2001 From: Ben Pfaff Date: Tue, 26 Aug 2008 03:05:05 +0000 Subject: [PATCH] Reboot when Ctrl+Alt+Del is pressed. Suggested by Anthony Romano. Implementation with assistance from and reviewed by Godmar Back. --- src/devices/kbd.c | 8 +++++- src/devices/timer.c | 67 +++++++++++++++++++++++++++++++++++++++------ src/devices/timer.h | 6 ++++ src/threads/init.c | 6 ++-- 4 files changed, 75 insertions(+), 12 deletions(-) diff --git a/src/devices/kbd.c b/src/devices/kbd.c index 4d7dfdf..1aa71f5 100644 --- a/src/devices/kbd.c +++ b/src/devices/kbd.c @@ -4,6 +4,7 @@ #include #include #include "devices/input.h" +#include "threads/init.h" #include "threads/interrupt.h" #include "threads/io.h" @@ -53,7 +54,7 @@ struct keymap that we handle elsewhere. */ static const struct keymap invariant_keymap[] = { - {0x01, "\033"}, + {0x01, "\033"}, /* Escape. */ {0x0e, "\b"}, {0x0f, "\tQWERTYUIOP"}, {0x1c, "\r"}, @@ -61,6 +62,7 @@ static const struct keymap invariant_keymap[] = {0x2c, "ZXCVBNM"}, {0x37, "*"}, {0x39, " "}, + {0x53, "\177"}, /* Delete. */ {0, NULL}, }; @@ -131,6 +133,10 @@ keyboard_interrupt (struct intr_frame *args UNUSED) /* Ordinary character. */ if (!release) { + /* Reboot if Ctrl+Alt+Del pressed. */ + if (c == 0177 && ctrl && alt) + reboot (); + /* Handle Ctrl, Shift. Note that Ctrl overrides Shift. */ if (ctrl && c >= 0x40 && c < 0x60) diff --git a/src/devices/timer.c b/src/devices/timer.c index a4521de..70234a8 100644 --- a/src/devices/timer.c +++ b/src/devices/timer.c @@ -28,6 +28,7 @@ static intr_handler_func timer_interrupt; static bool too_many_loops (unsigned loops); static void busy_wait (int64_t loops); static void real_time_sleep (int64_t num, int32_t denom); +static void real_time_delay (int64_t num, int32_t denom); /* Sets up the 8254 Programmable Interval Timer (PIT) to interrupt PIT_FREQ times per second, and registers the @@ -92,7 +93,8 @@ timer_elapsed (int64_t then) return timer_ticks () - then; } -/* Suspends execution for approximately TICKS timer ticks. */ +/* Sleeps for approximately TICKS timer ticks. Interrupts must + be turned on. */ void timer_sleep (int64_t ticks) { @@ -103,27 +105,69 @@ timer_sleep (int64_t ticks) thread_yield (); } -/* Suspends execution for approximately MS milliseconds. */ +/* Sleeps for approximately MS milliseconds. Interrupts must be + turned on. */ void timer_msleep (int64_t ms) { real_time_sleep (ms, 1000); } -/* Suspends execution for approximately US microseconds. */ +/* Sleeps for approximately US microseconds. Interrupts must be + turned on. */ void timer_usleep (int64_t us) { real_time_sleep (us, 1000 * 1000); } -/* Suspends execution for approximately NS nanoseconds. */ +/* Sleeps for approximately NS nanoseconds. Interrupts must be + turned on. */ void timer_nsleep (int64_t ns) { real_time_sleep (ns, 1000 * 1000 * 1000); } +/* Busy-waits for approximately MS milliseconds. Interrupts need + not be turned on. + + Busy waiting wastes CPU cycles, and busy waiting with + interrupts off for the interval between timer ticks or longer + will cause timer ticks to be lost. Thus, use timer_msleep() + instead if interrupts are enabled. */ +void +timer_mdelay (int64_t ms) +{ + real_time_delay (ms, 1000); +} + +/* Sleeps for approximately US microseconds. Interrupts need not + be turned on. + + Busy waiting wastes CPU cycles, and busy waiting with + interrupts off for the interval between timer ticks or longer + will cause timer ticks to be lost. Thus, use timer_usleep() + instead if interrupts are enabled. */ +void +timer_udelay (int64_t us) +{ + real_time_delay (us, 1000 * 1000); +} + +/* Sleeps execution for approximately NS nanoseconds. Interrupts + need not be turned on. + + Busy waiting wastes CPU cycles, and busy waiting with + interrupts off for the interval between timer ticks or longer + will cause timer ticks to be lost. Thus, use timer_nsleep() + instead if interrupts are enabled.*/ +void +timer_ndelay (int64_t ns) +{ + real_time_delay (ns, 1000 * 1000 * 1000); +} + /* Prints timer statistics. */ void timer_print_stats (void) @@ -195,10 +239,17 @@ real_time_sleep (int64_t num, int32_t denom) else { /* Otherwise, use a busy-wait loop for more accurate - sub-tick timing. We scale the numerator and denominator - down by 1000 to avoid the possibility of overflow. */ - ASSERT (denom % 1000 == 0); - busy_wait (loops_per_tick * num / 1000 * TIMER_FREQ / (denom / 1000)); + sub-tick timing. */ + real_time_delay (num, denom); } } +/* Busy-wait for approximately NUM/DENOM seconds. */ +static void +real_time_delay (int64_t num, int32_t denom) +{ + /* Scale the numerator and denominator down by 1000 to avoid + the possibility of overflow. */ + ASSERT (denom % 1000 == 0); + busy_wait (loops_per_tick * num / 1000 * TIMER_FREQ / (denom / 1000)); +} diff --git a/src/devices/timer.h b/src/devices/timer.h index 45a3f72..cd3d6bb 100644 --- a/src/devices/timer.h +++ b/src/devices/timer.h @@ -13,11 +13,17 @@ void timer_calibrate (void); int64_t timer_ticks (void); int64_t timer_elapsed (int64_t); +/* Sleep and yield the CPU to other threads. */ void timer_sleep (int64_t ticks); void timer_msleep (int64_t milliseconds); void timer_usleep (int64_t microseconds); void timer_nsleep (int64_t nanoseconds); +/* Busy waits. */ +void timer_mdelay (int64_t milliseconds); +void timer_udelay (int64_t microseconds); +void timer_ndelay (int64_t nanoseconds); + void timer_print_stats (void); #endif /* devices/timer.h */ diff --git a/src/threads/init.c b/src/threads/init.c index 9815a20..ac94603 100644 --- a/src/threads/init.c +++ b/src/threads/init.c @@ -396,15 +396,15 @@ reboot (void) { if ((inb (0x64) & 0x02) == 0) break; - timer_usleep (2); + timer_udelay (2); } - timer_usleep (50); + timer_udelay (50); /* Pulse bit 0 of the output port P2 of the keyboard controller. * This will reset the CPU. */ outb (0x64, 0xfe); - timer_usleep (50); + timer_udelay (50); } } -- 2.30.2