Make lfs bootable

[travis1829]

Booting with lfs now works.

• Most basic user programs (ls, cat, grep, wc, etc.) work fine.

• Reading anything (inode, data) seems to work fine, but trying to write something seems to sometimes causes a problem.

• kernel booting
  • kernel main: O
  • superblock load: O
  • checkpoint load: O
  • imap load: O
  • inode, data block load: O
• user program init
  • exec: O
  • run sh: O
• user programs
  • cat O
  • echo O
  • forktest O
  • grep O
  • init O
  • ln X -> O
  • ls O
  • mkdir X -> O
  • rm X -> O
  • sh O
  • stressfs X
  • usertests X
  • most tests not related to fs seem to work
  • grind X
  • wc O
  • zombie O
  • hello O

To run, do

make clean
FS=lfs CPUS=1 make qemu

[haan6]

Will this code pass if we add tests with features=lfs to GitHub CI?

[travis1829]

Will this code pass if we add tests with features=lfs to GitHub CI?

Currently, the rv6 with lfs will pass only a few of usertests related to file system, so I think we should add CI checks later.

[jeehoonkang]

bors r+

[kaist-cp-bors[bot]]

Build succeeded:

• ci