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| author | Michael Walle <michael@walle.cc> | 2012-06-05 11:33:16 +0000 |
|---|---|---|
| committer | Albert ARIBAUD <albert.u.boot@aribaud.net> | 2012-07-07 14:07:32 +0200 |
| commit | 03c1b04f86ddd6a296e2d80d73f5e4670e55da1d (patch) | |
| tree | b4d8209cc1b1dee7b0ced4ab179c09b01cc5ab52 | |
| parent | 99e139d5902e488eb779cd4f00c978f3803c39be (diff) | |
| download | u-boot-03c1b04f86ddd6a296e2d80d73f5e4670e55da1d.tar.gz | |
net: add helper to generate random mac address
Add new function eth_random_enetaddr() to generate a locally administered
ethernet address.
Signed-off-by: Michael Walle <michael@walle.cc>
Acked-by: Joe Hershberger <joe.hershberger@gmail.com>
| -rw-r--r-- | include/net.h | 17 | ||||
| -rw-r--r-- | net/eth.c | 22 |
2 files changed, 39 insertions, 0 deletions
diff --git a/include/net.h b/include/net.h index a092f291bb..6d2d6cd849 100644 --- a/include/net.h +++ b/include/net.h @@ -122,6 +122,23 @@ extern int eth_setenv_enetaddr(char *name, const uchar *enetaddr); extern int eth_getenv_enetaddr_by_index(const char *base_name, int index, uchar *enetaddr); +#ifdef CONFIG_RANDOM_MACADDR +/* + * The u-boot policy does not allow hardcoded ethernet addresses. Under the + * following circumstances a random generated address is allowed: + * - in emergency cases, where you need a working network connection to set + * the ethernet address. + * Eg. you want a rescue boot and don't have a serial port to access the + * CLI to set environment variables. + * + * In these cases, we generate a random locally administered ethernet address. + * + * Args: + * enetaddr - returns 6 byte hardware address + */ +extern void eth_random_enetaddr(uchar *enetaddr); +#endif + extern int usb_eth_initialize(bd_t *bi); extern int eth_init(bd_t *bis); /* Initialize the device */ extern int eth_send(void *packet, int length); /* Send a packet */ @@ -70,6 +70,28 @@ static int eth_mac_skip(int index) return ((skip_state = getenv(enetvar)) != NULL); } +#ifdef CONFIG_RANDOM_MACADDR +void eth_random_enetaddr(uchar *enetaddr) +{ + uint32_t rval; + + srand(get_timer(0)); + + rval = rand(); + enetaddr[0] = rval & 0xff; + enetaddr[1] = (rval >> 8) & 0xff; + enetaddr[2] = (rval >> 16) & 0xff; + + rval = rand(); + enetaddr[3] = rval & 0xff; + enetaddr[4] = (rval >> 8) & 0xff; + enetaddr[5] = (rval >> 16) & 0xff; + + /* make sure it's local and unicast */ + enetaddr[0] = (enetaddr[0] | 0x02) & ~0x01; +} +#endif + /* * CPU and board-specific Ethernet initializations. Aliased function * signals caller to move on |