Merge 14369675da8f59b36e7d99535bd7ddb56bf23c33 into 7a85414eced71d3208d0cbffa1a9e7a6a0b5fcc1

CMakeLists.txt

@@ -9,7 +9,7 @@ option(BLISP_USE_SYSTEM_LIBRARIES "Use system-installed libraries" "${CMAKE_USE_
 option(COMPILE_TESTS "Compile the tests" OFF)
 
 add_library(libblisp_obj OBJECT
-        lib/blisp.c lib/blisp_easy.c
+        lib/blisp.c lib/blisp_easy.c lib/crc.c
         lib/chip/blisp_chip_bl60x.c
         lib/chip/blisp_chip_bl70x.c
         lib/chip/blisp_chip_bl808.c)

include/crc.h

@@ -0,0 +1,6 @@
+#ifndef _BLISP_CRC_H
+#define _BLISP_CRC_H
+
+unsigned long crc(unsigned char *buf, int len);
+
+#endif // _BLISP_CRC_H

lib/chip/blisp_chip_bl808.c

@@ -5,7 +5,7 @@
 
 #include "blisp.h"
 #include "blisp_struct.h"
-#include "blisp_util.h"
+#include "crc.h"
 #include <stddef.h>
 
 struct blisp_chip blisp_chip_bl808 = {
@@ -225,7 +225,7 @@ struct bl808_bootheader_t bl808_header = {
 };
 
 void fill_crcs(struct bl808_bootheader_t *bh) {
-    bh->flash_cfg.crc32 = crc32_calculate((unsigned char *) &bh->flash_cfg.cfg, sizeof(struct bl808_spi_flash_cfg_t));
+    bh->flash_cfg.crc32 = crc((unsigned char *) &bh->flash_cfg.cfg, sizeof(struct bl808_spi_flash_cfg_t));
-    bh->clk_cfg.crc32 = crc32_calculate((unsigned char *) &bh->clk_cfg.cfg, sizeof(struct bl808_sys_clk_cfg_t));
+    bh->clk_cfg.crc32 = crc((unsigned char *) &bh->clk_cfg.cfg, sizeof(struct bl808_sys_clk_cfg_t));
-    bh->crc32 = crc32_calculate((unsigned char *) bh, sizeof(struct bl808_bootheader_t) - 4);
+    bh->crc32 = crc((unsigned char *) bh, sizeof(struct bl808_bootheader_t) - 4);
 }

lib/crc.c

@@ -0,0 +1,69 @@
+/*
+ * CRC code taken from https://www.rfc-editor.org/rfc/rfc1952#section-8
+ *
+ * Copyright (c) 1996 L. Peter Deutsch
+ *
+ * Permission is granted to copy and distribute this document for any
+ * purpose and without charge, including translations into other
+ * languages and incorporation into compilations, provided that the
+ * copyright notice and this notice are preserved, and that any
+ * substantive changes or deletions from the original are clearly
+ * marked.
+ */
+
+#include <stdlib.h>
+#include <stdbool.h>
+
+/* Table of CRCs of all 8-bit messages. */
+unsigned long crc_table[256];
+
+/* Flag: has the table been computed? Initially false. */
+int crc_table_computed = 0;
+
+/* Make the table for a fast CRC. */
+void make_crc_table(void) {
+    unsigned long c;
+    int n, k;
+    for (n = 0; n < 256; n++) {
+        c = (unsigned long) n;
+        for (k = 0; k < 8; k++) {
+            if (c & 1) {
+                c = 0xedb88320L ^ (c >> 1);
+            } else {
+                c = c >> 1;
+            }
+        }
+        crc_table[n] = c;
+    }
+    crc_table_computed = 1;
+}
+
+/*
+ Update a running crc with the bytes buf[0..len-1] and return
+the updated crc. The crc should be initialized to zero. Pre- and
+post-conditioning (one's complement) is performed within this
+function so it shouldn't be done by the caller. Usage example:
+
+ unsigned long crc = 0L;
+
+ while (read_buffer(buffer, length) != EOF) {
+   crc = update_crc(crc, buffer, length);
+ }
+ if (crc != original_crc) error();
+*/
+unsigned long update_crc(unsigned long crc, unsigned char *buf, int len) {
+    unsigned long c = crc ^ 0xffffffffL;
+    int n;
+
+    if (!crc_table_computed)
+        make_crc_table();
+    for (n = 0; n < len; n++) {
+        c = crc_table[(c ^ buf[n]) & 0xff] ^ (c >> 8);
+    }
+    return c ^ 0xffffffffL;
+}
+
+/* Return the CRC of the bytes buf[0..len-1]. */
+unsigned long crc(unsigned char *buf, int len) {
+    return update_crc(0L, buf, len);
+}