[kernel] Change bioshd minor numbering scheme to conserve kernel data size #1710
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The BIOS disk driver allowed for 32 sub-disks (partitions) on each drive, this changes that to 8. This saves 1152 bytes in the kernel data segment, previously used for absolutely nothing!! We now probably have enough free data space in the kernel data segment to consider moving to dynamic task structure allocation, which could allow for more processes to run on ELKS (current limit is 16).
The net effect is that the normal boot drive (/dev/fd0) device number is changed from 0380 to 0320 on boot. /dev/fd1 is now 0328. /dev/hda is still 0300, but numbers for hard drives B,C and D changed. This PR is possible given the large number of other changes made to the BIOS driver recently.
None of this should have any effect on /bootopts, configuration options or ELKS operation.