diff --git a/stand/libsa/zfs/Makefile.inc b/stand/libsa/zfs/Makefile.inc
index f4cecdbc3085..7660f4ab7baf 100644
--- a/stand/libsa/zfs/Makefile.inc
+++ b/stand/libsa/zfs/Makefile.inc
@@ -19,6 +19,7 @@ ZSTD_SRC+=	zstd_common.c
 ZSTD_SRC+=	zstd_ddict.c zstd_decompress.c zstd_decompress_block.c
 ZSTD_SRC+=	zstd_double_fast.c zstd_fast.c zstd_lazy.c zstd_ldm.c
 
+# This is completely bogus: We should be able to omit this code completely.
 .if ${MACHINE_ARCH} == "aarch64"
 ZFS_SRC_AS =	b3_aarch64_sse2.S b3_aarch64_sse41.S
 .endif
@@ -90,10 +91,13 @@ CFLAGS.skein_block.c+=	-DSKEIN_LOOP=111
 
 # To find blake3_impl.c in OpenZFS tree for our somehat ugly blake3_impl_hack.c
 # that's needed until the necessary tweaks can be upstreamed.
+# XXX the last import gutted all this since upstream changes broke this hack.
 CFLAGS.blake3_impl_hack.c+= -I${OZFS}/module/icp/algs/blake3 -I${OZFS}/module/icp/include
 
 CWARNFLAGS.zfs.c+= ${NO_WDANGLING_POINTER}
 
+# Needing to remove the -mgeneral-regs-only is a red flag that this is not quite
+# right. But it's needed at the moment due to the muddled upstream.
 b3_aarch64_sse2.o: b3_aarch64_sse2.S
 	${CC} -c ${CFLAGS:N-mgeneral-regs-only} ${WERROR} ${.IMPSRC} \
 	    -o ${.TARGET}