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https://github.com/brain-hackers/u-boot-brain
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8a0c6d6fa9
TI platforms such as OMAP5uevm, PandaBoard, use equivalent logic to generate fake USB MAC address from device unique DIE ID. Consolidate this to a generic location such that other TI platforms such as BeagleBoard-XM can also use the same. NOTE: at this point in time, I dont yet see a need for a generic dummy ethernet MAC address creation function, but if there is a need in the future, this can be further abstracted out. Signed-off-by: Nishanth Menon <nm@ti.com>
63 lines
1.4 KiB
C
63 lines
1.4 KiB
C
/*
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* Copyright 2011 Linaro Limited
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* Aneesh V <aneesh@ti.com>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <asm/arch/sys_proto.h>
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static void do_cancel_out(u32 *num, u32 *den, u32 factor)
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{
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while (1) {
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if (((*num)/factor*factor == (*num)) &&
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((*den)/factor*factor == (*den))) {
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(*num) /= factor;
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(*den) /= factor;
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} else
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break;
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}
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}
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/*
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* Cancel out the denominator and numerator of a fraction
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* to get smaller numerator and denominator.
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*/
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void cancel_out(u32 *num, u32 *den, u32 den_limit)
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{
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do_cancel_out(num, den, 2);
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do_cancel_out(num, den, 3);
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do_cancel_out(num, den, 5);
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do_cancel_out(num, den, 7);
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do_cancel_out(num, den, 11);
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do_cancel_out(num, den, 13);
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do_cancel_out(num, den, 17);
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while ((*den) > den_limit) {
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*num /= 2;
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/*
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* Round up the denominator so that the final fraction
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* (num/den) is always <= the desired value
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*/
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*den = (*den + 1) / 2;
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}
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}
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void __weak usb_fake_mac_from_die_id(u32 *id)
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{
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uint8_t device_mac[6];
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if (!getenv("usbethaddr")) {
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/*
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* create a fake MAC address from the processor ID code.
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* first byte is 0x02 to signify locally administered.
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*/
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device_mac[0] = 0x02;
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device_mac[1] = id[3] & 0xff;
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device_mac[2] = id[2] & 0xff;
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device_mac[3] = id[1] & 0xff;
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device_mac[4] = id[0] & 0xff;
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device_mac[5] = (id[0] >> 8) & 0xff;
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eth_setenv_enetaddr("usbethaddr", device_mac);
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}
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}
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