fs: Add semihosting filesystem
This adds a filesystem which is backed by the host's filesystem. It is
modeled off of sandboxfs, which has very similar aims. Semihosting
doesn't support listing directories (except with SYS_SYSTEM), so neither
do we. it's possible to optimize a bit for the common case of reading a
whole file by omitting a call to smh_seek, but this is left as a future
optimization.
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
diff --git a/include/fs.h b/include/fs.h
index b607b00..e2beba3 100644
--- a/include/fs.h
+++ b/include/fs.h
@@ -18,6 +18,7 @@
#define FS_TYPE_BTRFS 5
#define FS_TYPE_SQUASHFS 6
#define FS_TYPE_EROFS 7
+#define FS_TYPE_SEMIHOSTING 8
struct blk_desc;