Getting GOP Info | UEFI Dev (in C)

Channel:
United States Queso Fuego
Subscribers:
5,840
Published on ● Video Link: https://www.youtube.com/watch?v=y0JAycBdTjA


Duration: 1:34:43
636 views
30

Getting GOP (graphics output protocol) mode information, and faffing about a bit.
The next video will have setting the mode, but that's just calling SetMode() from the gop with a mode number.

Notes:
- Day 3.14159/infinity of changing audio settings: Added a noise gate filter for this video, but removed it afterwards, since it didn't really help that much and made things choppier.

- I did try and fix cerr for Reset(cerr, FALSE) to reset stderr, and it still doesn't work. It could be similar to simple pointer protocol where OVMF doesn't have a driver included by default, or stderr isn't connected by default, or something else is wrong.

Links:
https://uefi.org/specifications (uefi & other specifications)

UEFI Programming playlist:
https://www.youtube.com/playlist?list=PLT7NbkyNWaqZYHNLtOZ1MNxOt8myP5K0p

Git Repo:
https://github.com/queso-fuego/uefi-dev

Repo state at the start of this video:
git clone --recurse-submodules https://github.com/queso-fuego/uefi-dev
cd uefi-dev
git checkout 6602f47ad24c649b6400015925c4b38601c6a314

Repo state at the end of this video:
git checkout 1fb351194c9f28e93a5ebd072fe9a23c51833544

Next video:
- Making the GOP mode choices into a "scrolling" menu, and setting different GOP modes.

Join the Community Discord: https://discord.gg/yKm4T89QFn

Contact:
https://queso_fuego.srht.site/contact.html

- Let me know if there's anything specific you'd like to see!

Questions about setup/software/etc.?
Check the FAQ: https://queso_fuego.srht.site/about.html

Outline:
0:00:00 Combine printf number functions into 1 function; fail at using stderr
0:23:18 Set up initial empty menu option
0:31:33 Get GOP definitions from UEFI spec
0:58:31 Use LocateProtocol() & QueryMode() to (almost) get GOP info
1:24:40 Fix getting GOP by using pointer, not struct
1:31:32 Up Next & Outro

Music credits:
Winter Night by Sakura Girl | https://soundcloud.com/sakuragirl_official
Music promoted by https://www.chosic.com/free-music/all/
Creative Commons CC BY 3.0
https://creativecommons.org/licenses/by/3.0/

#uefidev #cprogramming #gop



Other Videos By Queso Fuego


2024-02-08Block IO Protocol Media Information | UEFI Dev (in C)
2024-01-17Delete File & Rename Commands | 32 Bit OS Dev (in C)
2024-01-16Reading Files in the EFI System Partition | UEFI Dev (in C)
2024-01-08Making an Initial File Tree | 32 Bit OS Dev (in C)
2023-11-28Absolute Pointer Protocol & Touchscreen | UEFI Dev (in C)
2023-11-22Timer Event & Printing Date/Time | UEFI Dev (in C)
2023-11-13Mouse Cursor & Simple Pointer Protocol | UEFI Dev (in C)
2023-11-10Make & Change Directory Commands | 32 Bit OS Dev (in C)
2023-11-07Loading ELF PIE Executables | 32 Bit OS Dev (in C)
2023-11-02Set GOP Mode With "Scrolling" Menu | UEFI Dev (in C)
2023-10-31Getting GOP Info | UEFI Dev (in C)
2023-10-08Reset/Shutdown & Main "Menu" | UEFI Dev (in C)
2023-10-05Get User Input / Set Text Mode | UEFI Dev (in C)
2023-10-02Basic Printf & Text Mode Info | UEFI Dev (in C)
2023-09-30Reading the Spec & Hello World | UEFI Dev (in C)
2023-06-26Command Line Flags 2/2 (VHD) | GPT Disk Image | UEFI Dev (in C)
2023-06-21Command Line Flags 1/2 | GPT Disk Image | UEFI Dev (in C)
2023-06-05Adding Files / Directories to the ESP | GPT Disk Image | UEFI Dev (in C)
2023-06-01EFI System Partition | GPT Disk Image | UEFI Dev (in C)
2023-05-29GPT Headers & Tables | GPT Disk Image | UEFI Dev (in C)
2023-05-26Protective MBR | GPT Disk Image | UEFI Dev (in C)


Tags:
queso fuego
gop modes
gop info
graphics output protocol
uefi dev
efi development
in C
c programming
low level
ovmf
emulation
qemu
graphics modes
locate protocol
uefi spec reading