Captain Bob, 2026-11-12: "Build an appropriate test harness! Love the idea."
The kernel had no tests below the boots, so defects QEMU cannot provoke could
not be tested first. Plan: docs/v4.0.0/plans/2026-11-12-kernel-host-tests.md.
kernel/tests/: one host program per kernel source, built with that source as
it is, the kernel's flags (-std=c99 -Wall -Wextra -Werror), and fakes --
the console captured line by line, a deterministic RNG that can fail, and a RAM
disk whose reads, writes or flushes fail at chosen 1 KiB blocks.
make -C kernel/tests test runs them; SRC_<test>= runs a test against other
code, which is how a test is seen to fail against the code before a fix.
test_gpt.c, 12 checks: a table written and read back; 16, 17 and 18 used
entries against max 16 and an entry out of range after the 16th (#180); the
RNG, the first write, a later write and a flush failing (#168). Against gpt.c
before #168 and #180: 4 failures, each defect caught. Now: 0. Both runs in
logs/.../kernel-tests/. Not yet a protocol stage: to rule (the plan, step 5).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017RzZgrf7V7Zk2iczBXDRbm
Claude
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