diff options
Diffstat (limited to 'src/boot/efi/console.c')
| -rw-r--r-- | src/boot/efi/console.c | 309 |
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 index 0000000..14c0008 --- /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; +} |