<p>fixeria would like tnt to <strong>review</strong> this change.</p><p><a href="https://gerrit.osmocom.org/c/libosmocore/+/18244">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">libosmogsm: import hopping sequence generation code<br><br>This implementation is taken from OsmocomBB, in particular from:<br><br> target/firmware/layer1/rfch.c<br><br>Change return type to uint16_t, because neither ARFCN, nor MAI<br>can be negative. Add prefix 'gsm0502_' to the function's name.<br><br>Change-Id: I8aba1578cc9d1bd89d4f5d33a6e8fedc8bea789a<br>Related: OS#4546<br>---<br>M include/osmocom/gsm/gsm0502.h<br>M src/gsm/gsm0502.c<br>M src/gsm/libosmogsm.map<br>3 files changed, 58 insertions(+), 0 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/44/18244/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/include/osmocom/gsm/gsm0502.h b/include/osmocom/gsm/gsm0502.h</span><br><span>index c9901df..cb993dc 100644</span><br><span>--- a/include/osmocom/gsm/gsm0502.h</span><br><span>+++ b/include/osmocom/gsm/gsm0502.h</span><br><span>@@ -47,3 +47,7 @@</span><br><span> };</span><br><span> </span><br><span> uint32_t gsm0502_fn_remap(uint32_t fn, enum gsm0502_fn_remap_channel channel);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+uint16_t gsm0502_hop_seq_gen(const struct gsm_time *t,</span><br><span style="color: hsl(120, 100%, 40%);">+ uint8_t hsn, uint8_t maio,</span><br><span style="color: hsl(120, 100%, 40%);">+ size_t n, const uint16_t *ma);</span><br><span>diff --git a/src/gsm/gsm0502.c b/src/gsm/gsm0502.c</span><br><span>index 68740dc..7e8dc92 100644</span><br><span>--- a/src/gsm/gsm0502.c</span><br><span>+++ b/src/gsm/gsm0502.c</span><br><span>@@ -2,6 +2,8 @@</span><br><span> * Paging helper code */</span><br><span> /*</span><br><span> * (C) 2009 by Holger Hans Peter Freyther <zecke@selfish.org></span><br><span style="color: hsl(120, 100%, 40%);">+ * (C) 2010 by Sylvain Munaut <tnt@246tNt.com></span><br><span style="color: hsl(120, 100%, 40%);">+ *</span><br><span> * All Rights Reserved</span><br><span> *</span><br><span> * SPDX-License-Identifier: GPL-2.0+</span><br><span>@@ -200,3 +202,54 @@</span><br><span> </span><br><span> return fn_map;</span><br><span> }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+/* Magic numbers (RNTABLE) for pseudo-random hopping sequence generation. */</span><br><span style="color: hsl(120, 100%, 40%);">+static const uint8_t rn_table[114] = {</span><br><span style="color: hsl(120, 100%, 40%);">+ 48, 98, 63, 1, 36, 95, 78, 102, 94, 73,</span><br><span style="color: hsl(120, 100%, 40%);">+ 0, 64, 25, 81, 76, 59, 124, 23, 104, 100,</span><br><span style="color: hsl(120, 100%, 40%);">+ 101, 47, 118, 85, 18, 56, 96, 86, 54, 2,</span><br><span style="color: hsl(120, 100%, 40%);">+ 80, 34, 127, 13, 6, 89, 57, 103, 12, 74,</span><br><span style="color: hsl(120, 100%, 40%);">+ 55, 111, 75, 38, 109, 71, 112, 29, 11, 88,</span><br><span style="color: hsl(120, 100%, 40%);">+ 87, 19, 3, 68, 110, 26, 33, 31, 8, 45,</span><br><span style="color: hsl(120, 100%, 40%);">+ 82, 58, 40, 107, 32, 5, 106, 92, 62, 67,</span><br><span style="color: hsl(120, 100%, 40%);">+ 77, 108, 122, 37, 60, 66, 121, 42, 51, 126,</span><br><span style="color: hsl(120, 100%, 40%);">+ 117, 114, 4, 90, 43, 52, 53, 113, 120, 72,</span><br><span style="color: hsl(120, 100%, 40%);">+ 16, 49, 7, 79, 119, 61, 22, 84, 9, 97,</span><br><span style="color: hsl(120, 100%, 40%);">+ 91, 15, 21, 24, 46, 39, 93, 105, 65, 70,</span><br><span style="color: hsl(120, 100%, 40%);">+ 125, 99, 17, 123,</span><br><span style="color: hsl(120, 100%, 40%);">+};</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+/*! Hopping sequence generation as per 3GPP TS 45.002, section 6.2.3. */</span><br><span style="color: hsl(120, 100%, 40%);">+uint16_t gsm0502_hop_seq_gen(const struct gsm_time *t,</span><br><span style="color: hsl(120, 100%, 40%);">+ uint8_t hsn, uint8_t maio,</span><br><span style="color: hsl(120, 100%, 40%);">+ size_t n, const uint16_t *ma)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ unsigned int mai;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ if (hsn == 0) {</span><br><span style="color: hsl(120, 100%, 40%);">+ /* cyclic hopping */</span><br><span style="color: hsl(120, 100%, 40%);">+ mai = (t->fn + maio) % n;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else {</span><br><span style="color: hsl(120, 100%, 40%);">+ /* pseudo random hopping */</span><br><span style="color: hsl(120, 100%, 40%);">+ int m, mp, tp, s, pnm;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ pnm = (n >> 0) | (n >> 1)</span><br><span style="color: hsl(120, 100%, 40%);">+ | (n >> 2) | (n >> 3)</span><br><span style="color: hsl(120, 100%, 40%);">+ | (n >> 4) | (n >> 5)</span><br><span style="color: hsl(120, 100%, 40%);">+ | (n >> 6);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ m = t->t2 + rn_table[(hsn ^ (t->t1 & 63)) + t->t3];</span><br><span style="color: hsl(120, 100%, 40%);">+ mp = m & pnm;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ if (mp < n)</span><br><span style="color: hsl(120, 100%, 40%);">+ s = mp;</span><br><span style="color: hsl(120, 100%, 40%);">+ else {</span><br><span style="color: hsl(120, 100%, 40%);">+ tp = t->t3 & pnm;</span><br><span style="color: hsl(120, 100%, 40%);">+ s = (mp + tp) % n;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ mai = (s + maio) % n;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ return ma ? ma[mai] : mai;</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span>diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map</span><br><span>index 1ff1286..ce55746 100644</span><br><span>--- a/src/gsm/libosmogsm.map</span><br><span>+++ b/src/gsm/libosmogsm.map</span><br><span>@@ -110,6 +110,7 @@</span><br><span> </span><br><span> gsm0502_calc_paging_group;</span><br><span> gsm0502_fn_remap;</span><br><span style="color: hsl(120, 100%, 40%);">+gsm0502_hop_seq_gen;</span><br><span> </span><br><span> gsm0503_xcch;</span><br><span> gsm0503_rach;</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/libosmocore/+/18244">change 18244</a>. 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<div style="display:none"> Gerrit-Project: libosmocore </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: I8aba1578cc9d1bd89d4f5d33a6e8fedc8bea789a </div>
<div style="display:none"> Gerrit-Change-Number: 18244 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: fixeria <axilirator@gmail.com> </div>
<div style="display:none"> Gerrit-Reviewer: tnt <tnt@246tNt.com> </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>