Skip to content

Identity-map complete vga region (0xa0000 to 0xc0000) - #104

Merged
phil-opp merged 2 commits into
rust-osdev:masterfrom
RKennedy9064:vga-mappings
Mar 16, 2020
Merged

Identity-map complete vga region (0xa0000 to 0xc0000)#104
phil-opp merged 2 commits into
rust-osdev:masterfrom
RKennedy9064:vga-mappings

Conversation

@RKennedy9064

@RKennedy9064 RKennedy9064 commented Mar 13, 2020

Copy link
Copy Markdown
Member

I took the existing method from vga_320x200 and extended it to map through 0xbffff. I also added it in vga_80x25 so that regions are mapped regardless of which feature someone uses. Let me know if anything looks off.

Edit (phil-opp): This PR extends the identity-mapping that we do for the VGA buffer at address 0xb8000 (or 0xa0000 with the vga_320x200) feature to all addresses in the range 0xa0000 to 0xc0000. This simplifies the switch to different VGA modes on the kernel side (see #99). This is a breaking change because it breaks kernels that try to map these virtual addresses themselves.

@RKennedy9064 RKennedy9064 mentioned this pull request Mar 13, 2020

@phil-opp phil-opp left a comment

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks! I have to small nits, otherwise this looks good to me.

Comment thread src/video_mode/vga_320x200.s Outdated
Comment thread src/video_mode/vga_text_80x25.s Outdated
Co-Authored-By: Philipp Oppermann <dev@phil-opp.com>
@RKennedy9064

Copy link
Copy Markdown
Member Author

Makes sense to me since technically 0xbffff is included in the final map. I added your suggestion.

@phil-opp phil-opp left a comment

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks!

@phil-opp phil-opp changed the title Mapping vga regions Identity-map complete vga region (0xa0000 to 0xc0000) Mar 16, 2020
@phil-opp
phil-opp merged commit 936e8c0 into rust-osdev:master Mar 16, 2020
phil-opp added a commit that referenced this pull request Mar 16, 2020
@phil-opp

Copy link
Copy Markdown
Member

Published as version 0.9.0

vinaychandra pushed a commit to vinaychandra/bootloader that referenced this pull request May 25, 2020
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

2 participants