tools: Add tool to add crc8 to a mac address

This patch adds a little tool that takes a generic MAC address and
generates a CRC byte for it. The output is the full MAC address without
any separators, ready written into an EEPROM.

Signed-off-by: Olliver Schinagl <o.schinagl@ultimaker.com>
Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

diff --git a/tools/.gitignore b/tools/.gitignore
index cb1e722d4575ec0d329fcdea86ec6b681cbfc53f..0d1f076d782aa33bc26a9c18c55074d76b272af6 100644 (file)
--- a/tools/.gitignore
+++ b/tools/.gitignore
@@ -6,6 +6,7 @@
 /fit_check_sign
 /fit_info
 /gen_eth_addr
+/gen_ethaddr_crc
 /ifdtool
 /img2srec
 /kwboot

diff --git a/tools/Makefile b/tools/Makefile
index 5e089c957e3aa894743db3347fe632d97e334748..eca8ecce107fb728310944dcfe33c72f1772bc85 100644 (file)
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -43,6 +43,10 @@ envcrc-objs := envcrc.o lib/crc32.o common/env_embedded.o lib/sha1.o
 hostprogs-$(CONFIG_CMD_NET) += gen_eth_addr
 HOSTCFLAGS_gen_eth_addr.o := -pedantic
 
+hostprogs-$(CONFIG_CMD_NET) += gen_ethaddr_crc
+gen_ethaddr_crc-objs := gen_ethaddr_crc.o lib/crc8.o
+HOSTCFLAGS_gen_ethaddr_crc.o := -pedantic
+
 hostprogs-$(CONFIG_CMD_LOADS) += img2srec
 HOSTCFLAGS_img2srec.o := -pedantic
 

diff --git a/tools/gen_ethaddr_crc.c b/tools/gen_ethaddr_crc.c
new file mode 100644 (file)
index 0000000..fe9896d
--- /dev/null
+++ b/tools/gen_ethaddr_crc.c
@@ -0,0 +1,75 @@
+/*
+ * (C) Copyright 2016
+ * Olliver Schinagl <oliver@schinagl.nl>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <ctype.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <u-boot/crc.h>
+
+#define ARP_HLEN 6 /* Length of hardware address */
+#define ARP_HLEN_ASCII (ARP_HLEN * 2) + (ARP_HLEN - 1) /* with separators */
+#define ARP_HLEN_LAZY (ARP_HLEN * 2) /* separatorless hardware address length */
+
+uint8_t nibble_to_hex(const char *nibble, bool lo)
+{
+       return (strtol(nibble, NULL, 16) << (lo ? 0 : 4)) & (lo ? 0x0f : 0xf0);
+}
+
+int process_mac(const char *mac_address)
+{
+       uint8_t ethaddr[ARP_HLEN + 1] = { 0x00 };
+       uint_fast8_t i = 0;
+
+       while (*mac_address != '\0') {
+               char nibble[2] = { 0x00, '\n' }; /* for strtol */
+
+               nibble[0] = *mac_address++;
+               if (isxdigit(nibble[0])) {
+                       if (isupper(nibble[0]))
+                               nibble[0] = tolower(nibble[0]);
+                       ethaddr[i >> 1] |= nibble_to_hex(nibble, (i % 2) != 0);
+                       i++;
+               }
+       }
+
+       for (i = 0; i < ARP_HLEN; i++)
+               printf("%.2x", ethaddr[i]);
+       printf("%.2x\n", crc8(0, ethaddr, ARP_HLEN));
+
+       return 0;
+}
+
+void print_usage(char *cmdname)
+{
+       printf("Usage: %s <mac_address>\n", cmdname);
+       puts("<mac_address> may be with or without separators.");
+       puts("Valid seperators are ':' and '-'.");
+       puts("<mac_address> digits are in base 16.\n");
+}
+
+int main(int argc, char *argv[])
+{
+       if (argc < 2) {
+               print_usage(argv[0]);
+               return 1;
+       }
+
+       if (!((strlen(argv[1]) == ARP_HLEN_ASCII) || (strlen(argv[1]) == ARP_HLEN_LAZY))) {
+               puts("The MAC address is not valid.\n");
+               print_usage(argv[0]);
+               return 1;
+       }
+
+       if (process_mac(argv[1])) {
+               puts("Failed to calculate the MAC's checksum.");
+               return 1;
+       }
+
+       return 0;
+}