Support mkfs.simplefs on macOS

[hsule]

Fixes issue#78 with enabling mkfs.simplefs to be compiled and executed on macOS. Currently, the utility depends on Linux-specific headers and ioctl operations, which prevents the rv32emu CI from running simplefs test cases on macOS runners.

---

Summary by cubic

Enable mkfs.simplefs to build and run on macOS by adding platform-specific headers, endian helpers, and block device size detection. This unblocks running simplefs tests on macOS runners while keeping Linux behavior unchanged.

• New Features
  • Add conditional includes for Linux and macOS; define htole/le macros via OSSwap* on macOS.
  • Implement macOS block device size detection using DKIOCGETBLOCKCOUNT and DKIOCGETBLOCKSIZE.
  • Retain Linux path using BLKGETSIZE64; no CLI or usage changes.
  • Add a macOS CI job that builds mkfs.simplefs and formats a test image.

^{Written for commit 1889a19. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 1 file

[ChinYikMing]

@hsule Rewrite commit message properly, check this ref.

[ChinYikMing]

Consider to add this build check:

diff --git a/mkfs.c b/mkfs.c
index 59dd967..c2f5626 100644
--- a/mkfs.c
+++ b/mkfs.c
@@ -1,3 +1,8 @@
+#if !defined(__linux__) && !defined(__APPLE__)
+#error \
+    "Do not manage to build this file unless your platform is Linux or macOS."
+#endif
+
 #include <fcntl.h>
 #include <linux/fs.h>
 #include <stdint.h>

[ChinYikMing]

Once this is fixed, consider to help to enable mounting simplefs on macOS runner at CI [1], [2].

[1] https://github.com/sysprog21/rv32emu/blob/master/.ci/boot-linux-prepare.sh
[2] https://github.com/sysprog21/rv32emu/blob/master/.ci/boot-linux.sh

[ChinYikMing]

Can you add CI for the verification?

[cubic-dev-ai]

1 issue found across 3 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name=".ci/test-mkfs-macos.sh">

<violation number="1" location=".ci/test-mkfs-macos.sh:16">
P2: macOS dd does not support the GNU `status=none` operand, so this dd call will fail and abort the macOS test run under `set -e`.</violation>
</file>

---

Since this is your first cubic review, here's how it works:

• cubic automatically reviews your code and comments on bugs and improvements
• Teach cubic by replying to its comments. cubic learns from your replies and gets better over time
• Ask questions if you need clarification on any suggestion

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[hsule]

@ChinYikMing Thanks for the review!
I’ve fixed the comments and added CI verification (macOS build + format a test image).
Could you please help check if everything looks good now?

[ChinYikMing]

rv32emu relies on tag rel2025.0, need to bump to rel2026.0 for this patch? cc @jserv .

[jserv]

rv32emu relies on tag rel2025.0, need to bump to rel2026.0 for this patch?

Yes, let's move forward.

[cubic-dev-ai]

No issues found across 3 files

[ChinYikMing]

LGTM!

[jserv]

Thank @hsule for contributing!

[hsule]

@jserv, since the PR is now merged, could you please help bump the tag to rel2026.0?
This will allow the reference in rv32emu to be updated, as mentioned in the previous comments:

Once this is fixed, consider to help to enable mounting simplefs on macOS runner at CI [1], [2].

[1] https://github.com/sysprog21/rv32emu/blob/master/.ci/boot-linux-prepare.sh [2] https://github.com/sysprog21/rv32emu/blob/master/.ci/boot-linux.sh

rv32emu relies on tag rel2025.0, need to bump to rel2026.0 for this patch? cc @jserv .

[jserv]

since the PR is now merged, could you please help bump the tag to rel2026.0? This will allow the reference in rv32emu to be updated, as mentioned in the previous comments:

I would like to wait for #79 and prepare new tag next week.