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| author | Konstantin Aladyshev <aladyshev22@gmail.com> | 2021-07-13 17:13:34 +0300 |
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| committer | Konstantin Aladyshev <aladyshev22@gmail.com> | 2021-07-13 17:17:24 +0300 |
| commit | c25ac9da7d848f722ee7b9ba6121639480030a82 (patch) | |
| tree | feb26938f3601aa289da5a48a9cb1d06bce1646d /Lessons | |
| parent | 26d9effc8a9162b8e7e66c1ff00e13c4b82b2e62 (diff) | |
| download | UEFI-Lessons-c25ac9da7d848f722ee7b9ba6121639480030a82.tar.gz UEFI-Lessons-c25ac9da7d848f722ee7b9ba6121639480030a82.tar.bz2 UEFI-Lessons-c25ac9da7d848f722ee7b9ba6121639480030a82.zip | |
Add information about escape sequences in QEMU 'nographic' mode
Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>
Diffstat (limited to 'Lessons')
| -rw-r--r-- | Lessons/Lesson_18/PageUp.png | bin | 0 -> 2088 bytes | |||
| -rw-r--r-- | Lessons/Lesson_18/README.md | 41 |
2 files changed, 39 insertions, 2 deletions
diff --git a/Lessons/Lesson_18/PageUp.png b/Lessons/Lesson_18/PageUp.png Binary files differnew file mode 100644 index 0000000..4ed626a --- /dev/null +++ b/Lessons/Lesson_18/PageUp.png diff --git a/Lessons/Lesson_18/README.md b/Lessons/Lesson_18/README.md index 228b311..cb566dc 100644 --- a/Lessons/Lesson_18/README.md +++ b/Lessons/Lesson_18/README.md @@ -101,8 +101,17 @@ Correct! FS0:\> ``` -With this app you can also look at how special keys are handled. -This is the output from "PageUp" key: +# Differences in keystroke handling with and without `-nographic` option in QEMU + +In our lessons we launch QEMU with a `-nographic` option: +``` +qemu-system-x86_64 \ + -drive if=pflash,format=raw,file=Build/OvmfX64/RELEASE_GCC5/FV/OVMF.fd \ + -drive format=raw,file=fat:rw:~/UEFI_disk \ + -nographic +``` + +With our app now you can observe how special keys are handled in this mode. For example this is the output from the "PageUp" key: ``` ScanCode = 0017, UnicodeChar = 0000 ( ) Wrong! @@ -113,4 +122,32 @@ Wrong! ScanCode = 0000, UnicodeChar = 007E (~) Wrong! ``` +But according to the UEFI spec and edk2 header for the `SimpleTextIn` protocol (https://github.com/tianocore/edk2/blob/master/MdePkg/Include/Protocol/SimpleTextIn.h) "PageUp" key should be displayed as a diferrent scan code, not as 4 symbols starting with the escape scan code: +``` +#define SCAN_PAGE_UP 0x0009 +... +#define SCAN_ESC 0x0017 +``` + +The problem is in the `-nographic` QEMU option. With it QEMU transforms all special keys to escape sequences like it happens in any console terminal. + +If you want to see 'native' behaviour you should run QEMU in graphic mode: +``` +qemu-system-x86_64 \ + -drive if=pflash,format=raw,file=Build/OvmfX64/RELEASE_GCC5/FV/OVMF.fd \ + -drive format=raw,file=fat:rw:~/UEFI_disk +``` +If your system doesn't support native graphics, you can run QEMU with a VNC option. QEMU will create a VNC server on the port that you've provided, and you can connect to that port via VNC client app (like VNC viewer for example https://www.realvnc.com/en/connect/download/viewer/). + +This command would produce VNC server on a `127.0.0.1:1` address: +``` +qemu-system-x86_64 \ + -drive if=pflash,format=raw,file=Build/OvmfX64/RELEASE_GCC5/FV/OVMF.fd \ + -drive format=raw,file=fat:rw:~/UEFI_disk \ + -vnc :1 +``` + +If you connect to QEMU launched with graphics you can observe that the "PageUp" press produces expected code: + + |
