duskos

commit 3199ff5d43e2c0a52e6428b91f81189ff50dd96d
parent 966859f51ed5db55a6fe362d08deb50db10f9cf5
Author: Virgil Dupras <hsoft@hardcoded.net>
Date:   Tue, 20 Sep 2022 19:19:33 -0400

lib/crc: fix algo and add crc32<<

Diffstat:
M
fs/lib/crc.c
 | 
4
++--
M
fs/lib/crc.fs
 | 
7
++++++-

2 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/fs/lib/crc.c b/fs/lib/crc.c
@@ -1,13 +1,13 @@
 extern unsigned int crc32(unsigned int crc, int c) {
     unsigned int i, b;
 
+    crc = crc ^ c;
     for (i=0; i<8; i++) {
-        b = (c ^ crc) & 1;
+        b = crc & 1;
         crc >>= 1;
         if (b) {
             crc = crc ^ $EDB88320;
         }
-        c >>= 1;
     }
     return crc;
 }
diff --git a/fs/lib/crc.fs b/fs/lib/crc.fs
@@ -5,4 +5,9 @@ cc<< lib/crc.c
 
 \ Computes CRC32 over range "a u".
 : crc32[] ( a u -- crc )
-  swap >r >r -1 begin ( n ) 8b to@+ V1 crc32 next -1 xor rdrop ;
+  swap >r >r -1 begin ( n ) 8b to@+ V1 crc32 next ^ rdrop ;
+
+: crc32<< ( -- crc )
+  word curpath :find# Path :open -1 begin ( hdl crc )
+    over IO :getc dup 0>= while crc32 repeat
+  drop swap IO :close ( ~crc ) ^ ;