ARM: meson: add unique MAC address generation

Add support for generating an unique MAC address using the SoC internal
serial number from the Secure Monitor interface.

The algorithm generates an unicast locally administered 6bytes minus 2bits
address using an crc16 of the serial for the top 16bits with the lower 2 bits
masked to setup the unicast locally administered property and a crc24 for
the lower 24bits.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>

diff --git a/arch/arm/include/asm/arch-meson/eth.h b/arch/arm/include/asm/arch-meson/eth.h
index 08acc5cbf74a6f1a765f7591c9822e0378e6a3d4..f765cd7c4ca1ba4c0bbc9bbb694017b229fab669 100644 (file)
--- a/arch/arm/include/asm/arch-meson/eth.h
+++ b/arch/arm/include/asm/arch-meson/eth.h
@@ -19,4 +19,7 @@ enum {
  */
 void meson_eth_init(phy_interface_t mode, unsigned int flags);
 
+/* Generate an unique MAC address based on the HW serial */
+int meson_generate_serial_ethaddr(void);
+
 #endif /* __MESON_ETH_H__ */

diff --git a/arch/arm/include/asm/arch-meson/sm.h b/arch/arm/include/asm/arch-meson/sm.h
index a5bac5abda0fb2fc9bdb7209f6d87d5401d86fd4..60d04ae22838912ca72745db585a06fbb9d0c2bb 100644 (file)
--- a/arch/arm/include/asm/arch-meson/sm.h
+++ b/arch/arm/include/asm/arch-meson/sm.h
@@ -7,6 +7,9 @@
 #define __MESON_SM_H__
 
 ssize_t meson_sm_read_efuse(uintptr_t offset, void *buffer, size_t size);
+
+#define SM_SERIAL_SIZE 12
+
 int meson_sm_get_serial(void *buffer, size_t size);
 
 #endif /* __MESON_SM_H__ */

diff --git a/arch/arm/mach-meson/board-common.c b/arch/arm/mach-meson/board-common.c
index 8c41301674e3eafb67f69f161f80b610c29e7f20..18383f774ee1d24aeb813ea30300be602a22356a 100644 (file)
--- a/arch/arm/mach-meson/board-common.c
+++ b/arch/arm/mach-meson/board-common.c
@@ -7,6 +7,7 @@
 #include <asm/arch/boot.h>
 #include <linux/libfdt.h>
 #include <linux/err.h>
+#include <environment.h>
 #include <asm/arch/mem.h>
 #include <asm/arch/sm.h>
 #include <asm/armv8/mmu.h>
@@ -67,6 +68,36 @@ void meson_board_add_reserved_memory(void *fdt, u64 start, u64 size)
        }
 }
 
+int meson_generate_serial_ethaddr(void)
+{
+       u8 mac_addr[ARP_HLEN];
+       char serial[SM_SERIAL_SIZE];
+       u32 sid;
+       u16 sid16;
+
+       if (!meson_sm_get_serial(serial, SM_SERIAL_SIZE)) {
+               sid = crc32(0, (unsigned char *)serial, SM_SERIAL_SIZE);
+               sid16 = crc16_ccitt(0, (unsigned char *)serial, SM_SERIAL_SIZE);
+
+               /* Ensure the NIC specific bytes of the mac are not all 0 */
+               if ((sid & 0xffffff) == 0)
+                       sid |= 0x800000;
+
+               /* Non OUI / registered MAC address */
+               mac_addr[0] = ((sid16 >> 8) & 0xfc) | 0x02;
+               mac_addr[1] = (sid16 >>  0) & 0xff;
+               mac_addr[2] = (sid >> 24) & 0xff;
+               mac_addr[3] = (sid >> 16) & 0xff;
+               mac_addr[4] = (sid >>  8) & 0xff;
+               mac_addr[5] = (sid >>  0) & 0xff;
+
+               eth_env_set_enetaddr("ethaddr", mac_addr);
+       } else
+               return -EINVAL;
+
+       return 0;
+}
+
 static void meson_set_boot_source(void)
 {
        const char *source;