cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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sn9c2028.h (1165B)

      1/* SPDX-License-Identifier: GPL-2.0-or-later */
      2/*
      3 * SN9C2028 common functions
      4 *
      5 * Copyright (C) 2009 Theodore Kilgore <kilgota@auburn,edu>
      6 *
      7 * Based closely upon the file gspca/pac_common.h
      8 */
      9
     10static const unsigned char sn9c2028_sof_marker[] = {
     11	0xff, 0xff, 0x00, 0xc4, 0xc4, 0x96,
     12	0x00,
     13	0x00, /* seq */
     14	0x00,
     15	0x00,
     16	0x00, /* avg luminance lower 8 bit */
     17	0x00, /* avg luminance higher 8 bit */
     18};
     19
     20static unsigned char *sn9c2028_find_sof(struct gspca_dev *gspca_dev,
     21					unsigned char *m, int len)
     22{
     23	struct sd *sd = (struct sd *) gspca_dev;
     24	int i;
     25
     26	/* Search for the SOF marker (fixed part) in the header */
     27	for (i = 0; i < len; i++) {
     28		if ((m[i] == sn9c2028_sof_marker[sd->sof_read]) ||
     29		    (sd->sof_read > 5)) {
     30			sd->sof_read++;
     31			if (sd->sof_read == 11)
     32				sd->avg_lum_l = m[i];
     33			if (sd->sof_read == 12)
     34				sd->avg_lum = (m[i] << 8) + sd->avg_lum_l;
     35			if (sd->sof_read == sizeof(sn9c2028_sof_marker)) {
     36				gspca_dbg(gspca_dev, D_FRAM,
     37					  "SOF found, bytes to analyze: %u - Frame starts at byte #%u\n",
     38					  len, i + 1);
     39				sd->sof_read = 0;
     40				return m + i + 1;
     41			}
     42		} else {
     43			sd->sof_read = 0;
     44		}
     45	}
     46
     47	return NULL;
     48}