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-rw-r--r--src/boot/efi/console.c309
1 files changed, 309 insertions, 0 deletions
diff --git a/src/boot/efi/console.c b/src/boot/efi/console.c
new file mode 100644
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--- /dev/null
+++ b/src/boot/efi/console.c
@@ -0,0 +1,309 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <efi.h>
+#include <efilib.h>
+
+#include "console.h"
+#include "util.h"
+
+#define SYSTEM_FONT_WIDTH 8
+#define SYSTEM_FONT_HEIGHT 19
+#define HORIZONTAL_MAX_OK 1920
+#define VERTICAL_MAX_OK 1080
+#define VIEWPORT_RATIO 10
+
+static inline void event_closep(EFI_EVENT *event) {
+ if (!*event)
+ return;
+
+ BS->CloseEvent(*event);
+}
+
+/*
+ * Reading input from the console sounds like an easy task to do, but thanks to broken
+ * firmware it is actually a nightmare.
+ *
+ * There is a SimpleTextInput and SimpleTextInputEx API for this. Ideally we want to use
+ * TextInputEx, because that gives us Ctrl/Alt/Shift key state information. Unfortunately,
+ * it is not always available and sometimes just non-functional.
+ *
+ * On some firmware, calling ReadKeyStroke or ReadKeyStrokeEx on the default console input
+ * device will just freeze no matter what (even though it *reported* being ready).
+ * Also, multiple input protocols can be backed by the same device, but they can be out of
+ * sync. Falling back on a different protocol can end up with double input.
+ *
+ * Therefore, we will preferably use TextInputEx for ConIn if that is available. Additionally,
+ * we look for the first TextInputEx device the firmware gives us as a fallback option. It
+ * will replace ConInEx permanently if it ever reports a key press.
+ * Lastly, a timer event allows us to provide a input timeout without having to call into
+ * any input functions that can freeze on us or using a busy/stall loop. */
+EFI_STATUS console_key_read(uint64_t *key, uint64_t timeout_usec) {
+ static EFI_SIMPLE_TEXT_INPUT_EX_PROTOCOL *conInEx = NULL, *extraInEx = NULL;
+ static bool checked = false;
+ UINTN index;
+ EFI_STATUS err;
+ _cleanup_(event_closep) EFI_EVENT timer = NULL;
+
+ assert(key);
+
+ if (!checked) {
+ /* Get the *first* TextInputEx device.*/
+ err = BS->LocateProtocol(&SimpleTextInputExProtocol, NULL, (void **) &extraInEx);
+ if (err != EFI_SUCCESS || BS->CheckEvent(extraInEx->WaitForKeyEx) == EFI_INVALID_PARAMETER)
+ /* If WaitForKeyEx fails here, the firmware pretends it talks this
+ * protocol, but it really doesn't. */
+ extraInEx = NULL;
+
+ /* Get the TextInputEx version of ST->ConIn. */
+ err = BS->HandleProtocol(ST->ConsoleInHandle, &SimpleTextInputExProtocol, (void **) &conInEx);
+ if (err != EFI_SUCCESS || BS->CheckEvent(conInEx->WaitForKeyEx) == EFI_INVALID_PARAMETER)
+ conInEx = NULL;
+
+ if (conInEx == extraInEx)
+ extraInEx = NULL;
+
+ checked = true;
+ }
+
+ err = BS->CreateEvent(EVT_TIMER, 0, NULL, NULL, &timer);
+ if (err != EFI_SUCCESS)
+ return log_error_status_stall(err, L"Error creating timer event: %r", err);
+
+ EFI_EVENT events[] = {
+ timer,
+ conInEx ? conInEx->WaitForKeyEx : ST->ConIn->WaitForKey,
+ extraInEx ? extraInEx->WaitForKeyEx : NULL,
+ };
+ UINTN n_events = extraInEx ? 3 : 2;
+
+ /* Watchdog rearming loop in case the user never provides us with input or some
+ * broken firmware never returns from WaitForEvent. */
+ for (;;) {
+ uint64_t watchdog_timeout_sec = 5 * 60,
+ watchdog_ping_usec = watchdog_timeout_sec / 2 * 1000 * 1000;
+
+ /* SetTimer expects 100ns units for some reason. */
+ err = BS->SetTimer(
+ timer,
+ TimerRelative,
+ MIN(timeout_usec, watchdog_ping_usec) * 10);
+ if (err != EFI_SUCCESS)
+ return log_error_status_stall(err, L"Error arming timer event: %r", err);
+
+ (void) BS->SetWatchdogTimer(watchdog_timeout_sec, 0x10000, 0, NULL);
+ err = BS->WaitForEvent(n_events, events, &index);
+ (void) BS->SetWatchdogTimer(watchdog_timeout_sec, 0x10000, 0, NULL);
+
+ if (err != EFI_SUCCESS)
+ return log_error_status_stall(err, L"Error waiting for events: %r", err);
+
+ /* We have keyboard input, process it after this loop. */
+ if (timer != events[index])
+ break;
+
+ /* The EFI timer fired instead. If this was a watchdog timeout, loop again. */
+ if (timeout_usec == UINT64_MAX)
+ continue;
+ else if (timeout_usec > watchdog_ping_usec) {
+ timeout_usec -= watchdog_ping_usec;
+ continue;
+ }
+
+ /* The caller requested a timeout? They shall have one! */
+ return EFI_TIMEOUT;
+ }
+
+ /* If the extra input device we found returns something, always use that instead
+ * to work around broken firmware freezing on ConIn/ConInEx. */
+ if (extraInEx && BS->CheckEvent(extraInEx->WaitForKeyEx) == EFI_SUCCESS) {
+ conInEx = extraInEx;
+ extraInEx = NULL;
+ }
+
+ /* Do not fall back to ConIn if we have a ConIn that supports TextInputEx.
+ * The two may be out of sync on some firmware, giving us double input. */
+ if (conInEx) {
+ EFI_KEY_DATA keydata;
+ uint32_t shift = 0;
+
+ err = conInEx->ReadKeyStrokeEx(conInEx, &keydata);
+ if (err != EFI_SUCCESS)
+ return err;
+
+ if (FLAGS_SET(keydata.KeyState.KeyShiftState, EFI_SHIFT_STATE_VALID)) {
+ /* Do not distinguish between left and right keys (set both flags). */
+ if (keydata.KeyState.KeyShiftState & EFI_CONTROL_PRESSED)
+ shift |= EFI_CONTROL_PRESSED;
+ if (keydata.KeyState.KeyShiftState & EFI_ALT_PRESSED)
+ shift |= EFI_ALT_PRESSED;
+ if (keydata.KeyState.KeyShiftState & EFI_LOGO_PRESSED)
+ shift |= EFI_LOGO_PRESSED;
+
+ /* Shift is not supposed to be reported for keys that can be represented as uppercase
+ * unicode chars (Shift+f is reported as F instead). Some firmware does it anyway, so
+ * filter those out. */
+ if ((keydata.KeyState.KeyShiftState & EFI_SHIFT_PRESSED) &&
+ keydata.Key.UnicodeChar == 0)
+ shift |= EFI_SHIFT_PRESSED;
+ }
+
+ /* 32 bit modifier keys + 16 bit scan code + 16 bit unicode */
+ *key = KEYPRESS(shift, keydata.Key.ScanCode, keydata.Key.UnicodeChar);
+ return EFI_SUCCESS;
+ } else if (BS->CheckEvent(ST->ConIn->WaitForKey) == EFI_SUCCESS) {
+ EFI_INPUT_KEY k;
+
+ err = ST->ConIn->ReadKeyStroke(ST->ConIn, &k);
+ if (err != EFI_SUCCESS)
+ return err;
+
+ *key = KEYPRESS(0, k.ScanCode, k.UnicodeChar);
+ return EFI_SUCCESS;
+ }
+
+ return EFI_NOT_READY;
+}
+
+static EFI_STATUS change_mode(int64_t mode) {
+ EFI_STATUS err;
+ int32_t old_mode;
+
+ /* SetMode expects a UINTN, so make sure these values are sane. */
+ mode = CLAMP(mode, CONSOLE_MODE_RANGE_MIN, CONSOLE_MODE_RANGE_MAX);
+ old_mode = MAX(CONSOLE_MODE_RANGE_MIN, ST->ConOut->Mode->Mode);
+
+ err = ST->ConOut->SetMode(ST->ConOut, mode);
+ if (err == EFI_SUCCESS)
+ return EFI_SUCCESS;
+
+ /* Something went wrong. Output is probably borked, so try to revert to previous mode. */
+ if (ST->ConOut->SetMode(ST->ConOut, old_mode) == EFI_SUCCESS)
+ return err;
+
+ /* Maybe the device is on fire? */
+ ST->ConOut->Reset(ST->ConOut, true);
+ ST->ConOut->SetMode(ST->ConOut, CONSOLE_MODE_RANGE_MIN);
+ return err;
+}
+
+EFI_STATUS query_screen_resolution(uint32_t *ret_w, uint32_t *ret_h) {
+ EFI_STATUS err;
+ EFI_GRAPHICS_OUTPUT_PROTOCOL *go;
+
+ err = BS->LocateProtocol(&GraphicsOutputProtocol, NULL, (void **) &go);
+ if (err != EFI_SUCCESS)
+ return err;
+
+ if (!go->Mode || !go->Mode->Info)
+ return EFI_DEVICE_ERROR;
+
+ *ret_w = go->Mode->Info->HorizontalResolution;
+ *ret_h = go->Mode->Info->VerticalResolution;
+ return EFI_SUCCESS;
+}
+
+static int64_t get_auto_mode(void) {
+ uint32_t screen_width, screen_height;
+
+ if (query_screen_resolution(&screen_width, &screen_height) == EFI_SUCCESS) {
+ bool keep = false;
+
+ /* Start verifying if we are in a resolution larger than Full HD
+ * (1920x1080). If we're not, assume we're in a good mode and do not
+ * try to change it. */
+ if (screen_width <= HORIZONTAL_MAX_OK && screen_height <= VERTICAL_MAX_OK)
+ keep = true;
+ /* For larger resolutions, calculate the ratio of the total screen
+ * area to the text viewport area. If it's less than 10 times bigger,
+ * then assume the text is readable and keep the text mode. */
+ else {
+ uint64_t text_area;
+ UINTN x_max, y_max;
+ uint64_t screen_area = (uint64_t)screen_width * (uint64_t)screen_height;
+
+ console_query_mode(&x_max, &y_max);
+ text_area = SYSTEM_FONT_WIDTH * SYSTEM_FONT_HEIGHT * (uint64_t)x_max * (uint64_t)y_max;
+
+ if (text_area != 0 && screen_area/text_area < VIEWPORT_RATIO)
+ keep = true;
+ }
+
+ if (keep)
+ return ST->ConOut->Mode->Mode;
+ }
+
+ /* If we reached here, then we have a high resolution screen and the text
+ * viewport is less than 10% the screen area, so the firmware developer
+ * screwed up. Try to switch to a better mode. Mode number 2 is first non
+ * standard mode, which is provided by the device manufacturer, so it should
+ * be a good mode.
+ * Note: MaxMode is the number of modes, not the last mode. */
+ if (ST->ConOut->Mode->MaxMode > CONSOLE_MODE_FIRMWARE_FIRST)
+ return CONSOLE_MODE_FIRMWARE_FIRST;
+
+ /* Try again with mode different than zero (assume user requests
+ * auto mode due to some problem with mode zero). */
+ if (ST->ConOut->Mode->MaxMode > CONSOLE_MODE_80_50)
+ return CONSOLE_MODE_80_50;
+
+ return CONSOLE_MODE_80_25;
+}
+
+EFI_STATUS console_set_mode(int64_t mode) {
+ switch (mode) {
+ case CONSOLE_MODE_KEEP:
+ /* If the firmware indicates the current mode is invalid, change it anyway. */
+ if (ST->ConOut->Mode->Mode < CONSOLE_MODE_RANGE_MIN)
+ return change_mode(CONSOLE_MODE_RANGE_MIN);
+ return EFI_SUCCESS;
+
+ case CONSOLE_MODE_NEXT:
+ if (ST->ConOut->Mode->MaxMode <= CONSOLE_MODE_RANGE_MIN)
+ return EFI_UNSUPPORTED;
+
+ mode = MAX(CONSOLE_MODE_RANGE_MIN, ST->ConOut->Mode->Mode);
+ do {
+ mode = (mode + 1) % ST->ConOut->Mode->MaxMode;
+ if (change_mode(mode) == EFI_SUCCESS)
+ break;
+ /* If this mode is broken/unsupported, try the next.
+ * If mode is 0, we wrapped around and should stop. */
+ } while (mode > CONSOLE_MODE_RANGE_MIN);
+
+ return EFI_SUCCESS;
+
+ case CONSOLE_MODE_AUTO:
+ return change_mode(get_auto_mode());
+
+ case CONSOLE_MODE_FIRMWARE_MAX:
+ /* Note: MaxMode is the number of modes, not the last mode. */
+ return change_mode(ST->ConOut->Mode->MaxMode - 1LL);
+
+ default:
+ return change_mode(mode);
+ }
+}
+
+EFI_STATUS console_query_mode(UINTN *x_max, UINTN *y_max) {
+ EFI_STATUS err;
+
+ assert(x_max);
+ assert(y_max);
+
+ err = ST->ConOut->QueryMode(ST->ConOut, ST->ConOut->Mode->Mode, x_max, y_max);
+ if (err != EFI_SUCCESS) {
+ /* Fallback values mandated by UEFI spec. */
+ switch (ST->ConOut->Mode->Mode) {
+ case CONSOLE_MODE_80_50:
+ *x_max = 80;
+ *y_max = 50;
+ break;
+ case CONSOLE_MODE_80_25:
+ default:
+ *x_max = 80;
+ *y_max = 25;
+ }
+ }
+
+ return err;
+}