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Update mbed_overrides.c

pull/1216/head
chris-styles 2015-06-30 03:18:36 +01:00
parent 81e206d2ad
commit d937b67ee7
1 changed files with 24 additions and 13 deletions
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37
libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KPSDK_MCUS/TARGET_MCU_K64F/TARGET_FRDM/mbed_overrides.c
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@ -34,21 +34,32 @@ void NMI_Handler(void)
// Provide ethernet devices with a semi-unique MAC address from the UUID
void mbed_mac_address(char *mac)
{
// Fetch word 0
uint32_t word0 = *(uint32_t *)0x40048060;
// Fetch word 1
// Making a random-as-possible MAC from 3 16 bit seeds and load of XOR'ing
uint16_t MAC[3]; // 3 16 bits words for the MAC
uint32_t UUID_LOC_BASE = 0x40048054;
// three random seeds to make a MAC
MAC[0] = 0x2055;
MAC[1] = 0x5c44;
MAC[2] = 0x79fe;
// XOR in each halfword of the UUID into each seed
for (int i=0;i<3;i++) {
for (int j=0;j<8;j++) {
MAC[i] ^= (*(uint32_t *)(UUID_LOC_BASE+(0x2*j)));
}
}
// we only want bottom 16 bits of word1 (MAC bits 32-47)
// and bit 1 forced to 1, bit 0 forced to 0
// and bit 9 forced to 1, bit 8 forced to 0
// Locally administered MAC, reduced conflicts
// http://en.wikipedia.org/wiki/MAC_address
uint32_t word1 = *(uint32_t *)0x4004805C;
word1 |= 0x00000002;
word1 &= 0x0000FFFE;
MAC[2] |= 0x0002;
MAC[2] &= 0xFFFE;
mac[0] = (word1 & 0x000000ff);
mac[1] = (word1 & 0x0000ff00) >> 8;
mac[2] = (word0 & 0xff000000) >> 24;
mac[3] = (word0 & 0x00ff0000) >> 16;
mac[4] = (word0 & 0x0000ff00) >> 8;
mac[5] = (word0 & 0x000000ff);
}