1 /* 2 * Xilinx eFuse/bbram CRC calculator 3 * 4 * Copyright (c) 2021 Xilinx Inc. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 #include "qemu/osdep.h" 25 #include "hw/nvram/xlnx-efuse.h" 26 27 static uint32_t xlnx_efuse_u37_crc(uint32_t prev_crc, uint32_t data, 28 uint32_t addr) 29 { 30 /* A table for 7-bit slicing */ 31 static const uint32_t crc_tab[128] = { 32 0x00000000, 0xe13b70f7, 0xc79a971f, 0x26a1e7e8, 33 0x8ad958cf, 0x6be22838, 0x4d43cfd0, 0xac78bf27, 34 0x105ec76f, 0xf165b798, 0xd7c45070, 0x36ff2087, 35 0x9a879fa0, 0x7bbcef57, 0x5d1d08bf, 0xbc267848, 36 0x20bd8ede, 0xc186fe29, 0xe72719c1, 0x061c6936, 37 0xaa64d611, 0x4b5fa6e6, 0x6dfe410e, 0x8cc531f9, 38 0x30e349b1, 0xd1d83946, 0xf779deae, 0x1642ae59, 39 0xba3a117e, 0x5b016189, 0x7da08661, 0x9c9bf696, 40 0x417b1dbc, 0xa0406d4b, 0x86e18aa3, 0x67dafa54, 41 0xcba24573, 0x2a993584, 0x0c38d26c, 0xed03a29b, 42 0x5125dad3, 0xb01eaa24, 0x96bf4dcc, 0x77843d3b, 43 0xdbfc821c, 0x3ac7f2eb, 0x1c661503, 0xfd5d65f4, 44 0x61c69362, 0x80fde395, 0xa65c047d, 0x4767748a, 45 0xeb1fcbad, 0x0a24bb5a, 0x2c855cb2, 0xcdbe2c45, 46 0x7198540d, 0x90a324fa, 0xb602c312, 0x5739b3e5, 47 0xfb410cc2, 0x1a7a7c35, 0x3cdb9bdd, 0xdde0eb2a, 48 0x82f63b78, 0x63cd4b8f, 0x456cac67, 0xa457dc90, 49 0x082f63b7, 0xe9141340, 0xcfb5f4a8, 0x2e8e845f, 50 0x92a8fc17, 0x73938ce0, 0x55326b08, 0xb4091bff, 51 0x1871a4d8, 0xf94ad42f, 0xdfeb33c7, 0x3ed04330, 52 0xa24bb5a6, 0x4370c551, 0x65d122b9, 0x84ea524e, 53 0x2892ed69, 0xc9a99d9e, 0xef087a76, 0x0e330a81, 54 0xb21572c9, 0x532e023e, 0x758fe5d6, 0x94b49521, 55 0x38cc2a06, 0xd9f75af1, 0xff56bd19, 0x1e6dcdee, 56 0xc38d26c4, 0x22b65633, 0x0417b1db, 0xe52cc12c, 57 0x49547e0b, 0xa86f0efc, 0x8ecee914, 0x6ff599e3, 58 0xd3d3e1ab, 0x32e8915c, 0x144976b4, 0xf5720643, 59 0x590ab964, 0xb831c993, 0x9e902e7b, 0x7fab5e8c, 60 0xe330a81a, 0x020bd8ed, 0x24aa3f05, 0xc5914ff2, 61 0x69e9f0d5, 0x88d28022, 0xae7367ca, 0x4f48173d, 62 0xf36e6f75, 0x12551f82, 0x34f4f86a, 0xd5cf889d, 63 0x79b737ba, 0x988c474d, 0xbe2da0a5, 0x5f16d052 64 }; 65 66 /* 67 * eFuse calculation is shown here: 68 * https://github.com/Xilinx/embeddedsw/blob/release-2019.2/lib/sw_services/xilskey/src/xilskey_utils.c#L1496 69 * 70 * Each u32 word is appended a 5-bit value, for a total of 37 bits; see: 71 * https://github.com/Xilinx/embeddedsw/blob/release-2019.2/lib/sw_services/xilskey/src/xilskey_utils.c#L1356 72 */ 73 uint32_t crc = prev_crc; 74 const unsigned rshf = 7; 75 const uint32_t im = (1 << rshf) - 1; 76 const uint32_t rm = (1 << (32 - rshf)) - 1; 77 const uint32_t i2 = (1 << 2) - 1; 78 const uint32_t r2 = (1 << 30) - 1; 79 80 unsigned j; 81 uint32_t i, r; 82 uint64_t w; 83 84 w = (uint64_t)(addr) << 32; 85 w |= data; 86 87 /* Feed 35 bits, in 5 rounds, each a slice of 7 bits */ 88 for (j = 0; j < 5; j++) { 89 r = rm & (crc >> rshf); 90 i = im & (crc ^ w); 91 crc = crc_tab[i] ^ r; 92 93 w >>= rshf; 94 } 95 96 /* Feed the remaining 2 bits */ 97 r = r2 & (crc >> 2); 98 i = i2 & (crc ^ w); 99 crc = crc_tab[i << (rshf - 2)] ^ r; 100 101 return crc; 102 } 103 104 uint32_t xlnx_efuse_calc_crc(const uint32_t *data, unsigned u32_cnt, 105 unsigned zpads) 106 { 107 uint32_t crc = 0; 108 unsigned index; 109 110 for (index = zpads; index; index--) { 111 crc = xlnx_efuse_u37_crc(crc, 0, (index + u32_cnt)); 112 } 113 114 for (index = u32_cnt; index; index--) { 115 crc = xlnx_efuse_u37_crc(crc, data[index - 1], index); 116 } 117 118 return crc; 119 } 120