diff options
author | Holger Hans Peter Freyther <holger@moiji-mobile.com> | 2013-09-29 07:37:40 +0200 |
---|---|---|
committer | Holger Hans Peter Freyther <holger@moiji-mobile.com> | 2013-10-30 14:45:57 +0100 |
commit | 02ab4a88039804ab3d09c5936f91bb0e4650a0a9 (patch) | |
tree | 44d25a2365279ac87a200a52670a6ae11ec719b2 /src/gprs_rlcmac.cpp | |
parent | 96173aec93104a23d3989da9bdf770a535701fef (diff) |
alloc: Move the two timeslot alloc algorithms to a dedicated file
Diffstat (limited to 'src/gprs_rlcmac.cpp')
-rw-r--r-- | src/gprs_rlcmac.cpp | 561 |
1 files changed, 0 insertions, 561 deletions
diff --git a/src/gprs_rlcmac.cpp b/src/gprs_rlcmac.cpp index e8041d2f..5bc58cff 100644 --- a/src/gprs_rlcmac.cpp +++ b/src/gprs_rlcmac.cpp @@ -24,54 +24,6 @@ #include <gprs_rlcmac.h> #include <tbf.h> -/* 3GPP TS 05.02 Annex B.1 */ - -#define MS_NA 255 /* N/A */ -#define MS_A 254 /* 1 with hopping, 0 without */ -#define MS_B 253 /* 1 with hopping, 0 without (change Rx to Tx)*/ -#define MS_C 252 /* 1 with hopping, 0 without (change Tx to Rx)*/ - -struct gprs_ms_multislot_class { - uint8_t rx, tx, sum; /* Maximum Number of Slots: RX, Tx, Sum Rx+Tx */ - uint8_t ta, tb, ra, rb; /* Minimum Number of Slots */ - uint8_t type; /* Type of Mobile */ -}; - -static const struct gprs_ms_multislot_class gprs_ms_multislot_class[32] = { -/* M-S Class Rx Tx Sum Tta Ttb Tra Trb Type */ -/* N/A */ { MS_NA,MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA }, -/* 1 */ { 1, 1, 2, 3, 2, 4, 2, 1 }, -/* 2 */ { 2, 1, 3, 3, 2, 3, 1, 1 }, -/* 3 */ { 2, 2, 3, 3, 2, 3, 1, 1 }, -/* 4 */ { 3, 1, 4, 3, 1, 3, 1, 1 }, -/* 5 */ { 2, 2, 4, 3, 1, 3, 1, 1 }, -/* 6 */ { 3, 2, 4, 3, 1, 3, 1, 1 }, -/* 7 */ { 3, 3, 4, 3, 1, 3, 1, 1 }, -/* 8 */ { 4, 1, 5, 3, 1, 2, 1, 1 }, -/* 9 */ { 3, 2, 5, 3, 1, 2, 1, 1 }, -/* 10 */ { 4, 2, 5, 3, 1, 2, 1, 1 }, -/* 11 */ { 4, 3, 5, 3, 1, 2, 1, 1 }, -/* 12 */ { 4, 4, 5, 2, 1, 2, 1, 1 }, -/* 13 */ { 3, 3, MS_NA, MS_NA, MS_A, 3, MS_A, 2 }, -/* 14 */ { 4, 4, MS_NA, MS_NA, MS_A, 3, MS_A, 2 }, -/* 15 */ { 5, 5, MS_NA, MS_NA, MS_A, 3, MS_A, 2 }, -/* 16 */ { 6, 6, MS_NA, MS_NA, MS_A, 2, MS_A, 2 }, -/* 17 */ { 7, 7, MS_NA, MS_NA, MS_A, 1, 0, 2 }, -/* 18 */ { 8, 8, MS_NA, MS_NA, 0, 0, 0, 2 }, -/* 19 */ { 6, 2, MS_NA, 3, MS_B, 2, MS_C, 1 }, -/* 20 */ { 6, 3, MS_NA, 3, MS_B, 2, MS_C, 1 }, -/* 21 */ { 6, 4, MS_NA, 3, MS_B, 2, MS_C, 1 }, -/* 22 */ { 6, 4, MS_NA, 2, MS_B, 2, MS_C, 1 }, -/* 23 */ { 6, 6, MS_NA, 2, MS_B, 2, MS_C, 1 }, -/* 24 */ { 8, 2, MS_NA, 3, MS_B, 2, MS_C, 1 }, -/* 25 */ { 8, 3, MS_NA, 3, MS_B, 2, MS_C, 1 }, -/* 26 */ { 8, 4, MS_NA, 3, MS_B, 2, MS_C, 1 }, -/* 27 */ { 8, 4, MS_NA, 2, MS_B, 2, MS_C, 1 }, -/* 28 */ { 8, 6, MS_NA, 2, MS_B, 2, MS_C, 1 }, -/* 29 */ { 8, 8, MS_NA, 2, MS_B, 2, MS_C, 1 }, -/* N/A */ { MS_NA,MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA }, -/* N/A */ { MS_NA,MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA, MS_NA }, -}; struct gprs_rlcmac_cs gprs_rlcmac_cs[] = { /* frame length data block max payload */ @@ -230,519 +182,6 @@ int tfi_find_free(struct gprs_rlcmac_bts *bts, enum gprs_rlcmac_tbf_direction di return -1; } -static inline int8_t find_free_usf(struct gprs_rlcmac_pdch *pdch, uint8_t ts) -{ - struct gprs_rlcmac_tbf *tbf; - uint8_t usf_map = 0; - uint8_t tfi, usf; - - /* make map of used USF */ - for (tfi = 0; tfi < 32; tfi++) { - tbf = pdch->ul_tbf[tfi]; - if (!tbf) - continue; - usf_map |= (1 << tbf->dir.ul.usf[ts]); - } - - /* look for USF, don't use USF=7 */ - for (usf = 0; usf < 7; usf++) { - if (!(usf_map & (1 << usf))) - return usf; - } - - return -1; -} - -static void assign_uplink_tbf_usf(struct gprs_rlcmac_bts *bts, - struct gprs_rlcmac_pdch *pdch, - int ts, - struct gprs_rlcmac_tbf *tbf, int8_t usf) -{ - bts->trx[tbf->trx].ul_tbf[tbf->tfi] = tbf; - pdch->ul_tbf[tbf->tfi] = tbf; - tbf->pdch[ts] = pdch; - tbf->dir.ul.usf[ts] = usf; -} - -/* Slot Allocation: Algorithm A - * - * Assign single slot for uplink and downlink - */ -int alloc_algorithm_a(struct gprs_rlcmac_bts *bts, - struct gprs_rlcmac_tbf *old_tbf, - struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single) -{ - struct gprs_rlcmac_pdch *pdch; - uint8_t ts; - int8_t usf; /* must be signed */ - - LOGP(DRLCMAC, LOGL_DEBUG, "Slot Allocation (Algorithm A) for class " - "%d\n", tbf->ms_class); - - for (ts = 0; ts < 8; ts++) { - pdch = &bts->trx[tbf->trx].pdch[ts]; - if (!pdch->enable) { - LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, because " - "not enabled\n", ts); - continue; - } - break; - } - if (ts == 8) - return -EINVAL; - - tbf->tsc = pdch->tsc; - if (tbf->direction == GPRS_RLCMAC_UL_TBF) { - /* if USF available */ - usf = find_free_usf(pdch, ts); - if (usf < 0) { - LOGP(DRLCMAC, LOGL_NOTICE, "- Failed " - "allocating TS=%d, no USF available\n", ts); - return -EBUSY; - } - LOGP(DRLCMAC, LOGL_DEBUG, "- Assign uplink " - "TS=%d USF=%d\n", ts, usf); - assign_uplink_tbf_usf(bts, pdch, ts, tbf, usf); - } else { - LOGP(DRLCMAC, LOGL_DEBUG, "- Assign downlink TS=%d\n", ts); - bts->trx[tbf->trx].dl_tbf[tbf->tfi] = tbf; - pdch->dl_tbf[tbf->tfi] = tbf; - tbf->pdch[ts] = pdch; - } - /* the only one TS is the common TS */ - tbf->first_ts = tbf->first_common_ts = ts; - - return 0; -} - -/* Slot Allocation: Algorithm B - * - * Assign as many downlink slots as possible. - * Assign one uplink slot. (With free USF) - * - */ -int alloc_algorithm_b(struct gprs_rlcmac_bts *bts, - struct gprs_rlcmac_tbf *old_tbf, - struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single) -{ - struct gprs_rlcmac_pdch *pdch; - const struct gprs_ms_multislot_class *ms_class; - uint8_t Rx, Tx, Sum; /* Maximum Number of Slots: RX, Tx, Sum Rx+Tx */ - uint8_t Tta, Ttb, Tra, Trb, Tt, Tr; /* Minimum Number of Slots */ - uint8_t Type; /* Type of Mobile */ - uint8_t rx_win_min = 0, rx_win_max = 7; - uint8_t tx_win_min, tx_win_max, tx_range; - uint8_t rx_window = 0, tx_window = 0; - static const char *digit[10] = { "0","1","2","3","4","5","6","7","8","9" }; - int8_t usf[8] = { -1, -1, -1, -1, -1, -1, -1, -1 }; /* must be signed */ - int8_t tsc = -1; /* must be signed */ - int8_t first_common_ts = -1; - uint8_t i, ts; - uint8_t slotcount = 0; - - - if (tbf->ms_class >= 32) { - LOGP(DRLCMAC, LOGL_ERROR, "Multislot class %d out of range.\n", - tbf->ms_class); - return -EINVAL; - } - - if (tbf->ms_class) { - ms_class = &gprs_ms_multislot_class[tbf->ms_class]; - LOGP(DRLCMAC, LOGL_DEBUG, "Slot Allocation (Algorithm B) for " - "class %d\n", tbf->ms_class); - } else { - ms_class = &gprs_ms_multislot_class[12]; - LOGP(DRLCMAC, LOGL_DEBUG, "Slot Allocation (Algorithm B) for " - "unknow class (assuming 12)\n"); - } - - if (ms_class->tx == MS_NA) { - LOGP(DRLCMAC, LOGL_NOTICE, "Multislot class %d not " - "applicable.\n", tbf->ms_class); - return -EINVAL; - } - - Rx = ms_class->rx; -#if 0 - if (Rx > 4) { - LOGP(DRLCMAC, LOGL_DEBUG, "- Degrading max Rx slots to 4\n"); - Rx = 4; - } -#endif - Tx = ms_class->tx; -#if 0 - if (Tx > 4) { - LOGP(DRLCMAC, LOGL_DEBUG, "- Degrading max Tx slots to 4\n"); - Tx = 4; - } -#endif - Sum = ms_class->sum; - Tta = ms_class->ta; - Ttb = ms_class->tb; - Tra = ms_class->ra; - Trb = ms_class->rb; - Type = ms_class->type; - - /* Tta and Ttb may depend on hopping or frequency change */ - if (Ttb == MS_A) { - if (/* FIXME: hopping*/ 0) - Ttb = 1; - else - Ttb = 0; - } - if (Trb == MS_A) { - if (/* FIXME: hopping*/ 0) - Trb = 1; - else - Trb = 0; - } - if (Ttb == MS_B) { - /* FIXME: or frequency change */ - if (/* FIXME: hopping*/ 0) - Ttb = 1; - else - Ttb = 0; - } - if (Trb == MS_C) { - /* FIXME: or frequency change */ - if (/* FIXME: hopping*/ 0) - Trb = 1; - else - Trb = 0; - } - - LOGP(DRLCMAC, LOGL_DEBUG, "- Rx=%d Tx=%d Sum Rx+Tx=%s Tta=%s Ttb=%d " - " Tra=%d Trb=%d Type=%d\n", Rx, Tx, - (Sum == MS_NA) ? "N/A" : digit[Sum], - (Tta == MS_NA) ? "N/A" : digit[Tta], Ttb, Tra, Trb, Type); - - /* select the values for time contraints */ - if (/* FIXME: monitoring */0) { - /* applicable to type 1 and type 2 */ - Tt = Ttb; - Tr = Tra; - } else { - /* applicable to type 1 and type 2 */ - Tt = Ttb; - Tr = Trb; - } - - /* select a window of Rx slots if available - * The maximum allowed slots depend on RX or the window of available - * slots. - * This must be done for uplink TBF also, because it is the basis - * for calculating control slot and uplink slot(s). */ - for (ts = 0, i = 0; ts < 8; ts++) { - pdch = &bts->trx[tbf->trx].pdch[ts]; - /* check if enabled */ - if (!pdch->enable) { - LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, because " - "not enabled\n", ts); - /* increase window for Type 1 */ - if (Type == 1 && rx_window) - i++; - continue; - } - /* check if TSC changes */ - if (tsc < 0) - tbf->tsc = tsc = pdch->tsc; - else if (tsc != pdch->tsc) { - LOGP(DRLCMAC, LOGL_ERROR, "Skipping TS %d of TRX=%d, " - "because it has different TSC than lower TS " - "of TRX. In order to allow multislot, all " - "slots must be configured with the same " - "TSC!\n", ts, tbf->trx); - /* increase window for Type 1 */ - if (Type == 1 && rx_window) - i++; - continue; - } - - if (!rx_window) - rx_win_min = ts; - - rx_window |= (1 << ts); - LOGP(DRLCMAC, LOGL_DEBUG, "- Selected DL TS %d\n", ts); - - /* range of window (required for Type 1) */ - rx_win_max = ts; - - if (++i == Rx) { - LOGP(DRLCMAC, LOGL_DEBUG, "- Done, because slots / " - "window reached maximum alowed Rx size\n"); - break; - } - } - - LOGP(DRLCMAC, LOGL_DEBUG, "- Selected slots for RX: " - "(TS=0)\"%c%c%c%c%c%c%c%c\"(TS=7)\n", - ((rx_window & 0x01)) ? 'D' : '.', - ((rx_window & 0x02)) ? 'D' : '.', - ((rx_window & 0x04)) ? 'D' : '.', - ((rx_window & 0x08)) ? 'D' : '.', - ((rx_window & 0x10)) ? 'D' : '.', - ((rx_window & 0x20)) ? 'D' : '.', - ((rx_window & 0x40)) ? 'D' : '.', - ((rx_window & 0x80)) ? 'D' : '.'); - - /* reduce window, if existing uplink slots collide RX window */ - if (Type == 1 && old_tbf && old_tbf->direction == GPRS_RLCMAC_UL_TBF) { - uint8_t collide = 0, ul_usage = 0; - int j; - - /* calculate mask of colliding slots */ - for (ts = 0; ts < 8; ts++) { - if (old_tbf->pdch[ts]) { - ul_usage |= (1 << ts); - /* mark bits from TS-t .. TS+r */ - for (j = ts - Tt; j != ((ts + Tr + 1) & 7); - j = (j + 1) & 7) - collide |= (1 << j); - } - } - LOGP(DRLCMAC, LOGL_DEBUG, "- Not allowed slots due to existing " - "UL allocation: (TS=0)\"%c%c%c%c%c%c%c%c\"(TS=7) " - " D=downlink x=not usable\n", - ((ul_usage & 0x01)) ? 'D' : ((collide & 0x01))?'x':'.', - ((ul_usage & 0x02)) ? 'D' : ((collide & 0x02))?'x':'.', - ((ul_usage & 0x04)) ? 'D' : ((collide & 0x04))?'x':'.', - ((ul_usage & 0x08)) ? 'D' : ((collide & 0x08))?'x':'.', - ((ul_usage & 0x10)) ? 'D' : ((collide & 0x10))?'x':'.', - ((ul_usage & 0x20)) ? 'D' : ((collide & 0x20))?'x':'.', - ((ul_usage & 0x40)) ? 'D' : ((collide & 0x40))?'x':'.', - ((ul_usage & 0x80)) ? 'D' : ((collide & 0x80))?'x':'.'); - - /* apply mask to reduce tx_window (shifted by 3 slots) */ - rx_window &= ~(collide << 3); - rx_window &= ~(collide >> 5); - LOGP(DRLCMAC, LOGL_DEBUG, "- Remaining slots for RX: " - "(TS=0)\"%c%c%c%c%c%c%c%c\"(TS=7)\n", - ((rx_window & 0x01)) ? 'D' : '.', - ((rx_window & 0x02)) ? 'D' : '.', - ((rx_window & 0x04)) ? 'D' : '.', - ((rx_window & 0x08)) ? 'D' : '.', - ((rx_window & 0x10)) ? 'D' : '.', - ((rx_window & 0x20)) ? 'D' : '.', - ((rx_window & 0x40)) ? 'D' : '.', - ((rx_window & 0x80)) ? 'D' : '.'); - if (!rx_window) { - LOGP(DRLCMAC, LOGL_NOTICE, "No suitable downlink slots " - "available with current uplink assignment\n"); - return -EBUSY; - } - - /* calculate new min/max */ - for (ts = rx_win_min; ts <= rx_win_max; ts++) { - if ((rx_window & (1 << ts))) - break; - rx_win_min = ts + 1; - LOGP(DRLCMAC, LOGL_DEBUG, "- TS has been deleted, so " - "raising start of DL window to %d\n", - rx_win_min); - } - for (ts = rx_win_max; ts >= rx_win_min; ts--) { - if ((rx_window & (1 << ts))) - break; - rx_win_max = ts - 1; - LOGP(DRLCMAC, LOGL_DEBUG, "- TS has been deleted, so " - "lowering end of DL window to %d\n", - rx_win_max); - } - } - - /* reduce window, to allow at least one uplink TX slot - * this is only required for Type 1 */ - if (Type == 1 && rx_win_max - rx_win_min + 1 + Tt + 1 + Tr > 8) { - rx_win_max = rx_win_min + 7 - Tt - 1 - Tr; - LOGP(DRLCMAC, LOGL_DEBUG, "- Reduce RX window due to time " - "contraints to %d slots\n", - rx_win_max - rx_win_min + 1); - } - - LOGP(DRLCMAC, LOGL_DEBUG, "- RX-Window is: %d..%d\n", rx_win_min, - rx_win_max); - - /* calculate TX window */ - if (Type == 1) { - /* calculate TX window (shifted by 3 timeslots) - * it uses the space between tx_win_max and tx_win_min */ - tx_win_min = (rx_win_max - 2 + Tt) & 7; - tx_win_max = (rx_win_min + 4 - Tr) & 7; - /* calculate the TX window size (might be larger than Tx) */ - tx_range = (tx_win_max - tx_win_min + 1) & 7; - } else { - /* TX and RX simultaniously */ - tx_win_min = rx_win_min; - tx_win_max = 7; - /* TX window size (might be larger than Tx) */ - tx_range = tx_win_max - tx_win_min + 1; - } - - LOGP(DRLCMAC, LOGL_DEBUG, "- TX-Window is: %d..%d\n", tx_win_min, - tx_win_max); - - /* select a window of Tx slots if available - * The maximum allowed slots depend on TX or the window of available - * slots. - * - * also assign the first common ts, which is used for control or single - * slot. */ - if (tbf->direction == GPRS_RLCMAC_UL_TBF) { - for (ts = tx_win_min, i = 0; i < tx_range; ts = (ts + 1) & 7) { - pdch = &bts->trx[tbf->trx].pdch[ts]; - /* check if enabled */ - if (!pdch->enable) { - LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, " - "because not enabled\n", ts); - continue; - } - /* check if TSC changes */ - if (tsc < 0) - tbf->tsc = tsc = pdch->tsc; - else if (tsc != pdch->tsc) { - LOGP(DRLCMAC, LOGL_ERROR, "Skipping TS %d of " - "TRX=%d, because it has different TSC " - "than lower TS of TRX. In order to " - "allow multislot, all slots must be " - "configured with the same TSC!\n", - ts, tbf->trx); - /* increase window for Type 1 */ - if (Type == 1) - i++; - continue; - } - /* check for free usf */ - usf[ts] = find_free_usf(pdch, ts); - if (usf[ts] < 0) { - LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, " - "because no USF available\n", ts); - /* increase window for Type 1 */ - if (Type == 1) - i++; - continue; - } - - if (!tx_window) - first_common_ts = ts; - - tx_window |= (1 << ts); - LOGP(DRLCMAC, LOGL_DEBUG, "- Selected UL TS %d\n", ts); - - if (1 && Type == 1) { /* FIXME: multislot UL assignment */ - LOGP(DRLCMAC, LOGL_DEBUG, "- Done, because " - "1 slot assigned\n"); - break; - } - if (++i == Tx) { - LOGP(DRLCMAC, LOGL_DEBUG, "- Done, because " - "slots / window reached maximum " - "allowed Tx size\n"); - break; - } - } - - LOGP(DRLCMAC, LOGL_DEBUG, "- Selected TX window: " - "(TS=0)\"%c%c%c%c%c%c%c%c\"(TS=7)\n", - ((tx_window & 0x01)) ? 'U' : '.', - ((tx_window & 0x02)) ? 'U' : '.', - ((tx_window & 0x04)) ? 'U' : '.', - ((tx_window & 0x08)) ? 'U' : '.', - ((tx_window & 0x10)) ? 'U' : '.', - ((tx_window & 0x20)) ? 'U' : '.', - ((tx_window & 0x40)) ? 'U' : '.', - ((tx_window & 0x80)) ? 'U' : '.'); - - if (!tx_window) { - LOGP(DRLCMAC, LOGL_NOTICE, "No suitable uplink slots " - "available\n"); - return -EBUSY; - } - } else { - /* assign the first common ts, which is used for control or - * single slot. */ - for (ts = tx_win_min, i = 0; i < tx_range; ts = (ts + 1) & 7) { - pdch = &bts->trx[tbf->trx].pdch[ts]; - /* check if enabled */ - if (!pdch->enable) { - LOGP(DRLCMAC, LOGL_DEBUG, "- Skipping TS %d, " - "because not enabled\n", ts); - continue; - } - first_common_ts = ts; - break; - } - } - - if (first_common_ts < 0) { - LOGP(DRLCMAC, LOGL_NOTICE, "No first common slots available\n"); - return -EINVAL; - } - - if (tbf->direction == GPRS_RLCMAC_DL_TBF) { - /* assign downlink */ - if (rx_window == 0) { - LOGP(DRLCMAC, LOGL_NOTICE, "No downlink slots " - "available\n"); - return -EINVAL; - } - for (ts = 0; ts < 8; ts++) { - if ((rx_window & (1 << ts))) { - /* be sure to select a single downlink slots - * that can be used for uplink, if multiple - * slots are assigned later. */ - if (single && first_common_ts != ts) - continue; - LOGP(DRLCMAC, LOGL_DEBUG, "- Assigning DL TS " - "%d\n", ts); - pdch = &bts->trx[tbf->trx].pdch[ts]; - bts->trx[tbf->trx].dl_tbf[tbf->tfi] = tbf; - pdch->dl_tbf[tbf->tfi] = tbf; - tbf->pdch[ts] = pdch; - slotcount++; - if (slotcount == 1) - tbf->first_ts = ts; - if (single) - break; - } - } - } else { - /* assign uplink */ - if (tx_window == 0) { - LOGP(DRLCMAC, LOGL_NOTICE, "No uplink slots " - "available\n"); - return -EINVAL; - } - for (ts = 0; ts < 8; ts++) { - if ((tx_window & (1 << ts))) { - LOGP(DRLCMAC, LOGL_DEBUG, "- Assigning UL TS " - "%d\n", ts); - pdch = &bts->trx[tbf->trx].pdch[ts]; - assign_uplink_tbf_usf(bts, pdch, ts, tbf, usf[ts]); - slotcount++; - if (slotcount == 1) - tbf->first_ts = ts; - if (single) - break; - } - } - } - if (single && slotcount) { - LOGP(DRLCMAC, LOGL_INFO, "Using single slot at TS %d for %s\n", - tbf->first_ts, - (tbf->direction == GPRS_RLCMAC_DL_TBF) ? "DL" : "UL"); - } else { - LOGP(DRLCMAC, LOGL_INFO, "Using %d slots for %s\n", slotcount, - (tbf->direction == GPRS_RLCMAC_DL_TBF) ? "DL" : "UL"); - } - if (slotcount == 0) - return -EBUSY; - - tbf->first_common_ts = first_common_ts; - - return 0; -} - /* starting time for assigning single slot * This offset must be a multiple of 13. */ #define AGCH_START_OFFSET 52 |