--- /dev/null
+/*
+ * xtos-params.h -- user-settable parameters for XTOS single-threaded run-time
+ *
+ * Copyright (c) 2002, 2004, 2006-2007 Tensilica Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef XTOS_PARAMS_H
+#define XTOS_PARAMS_H
+
+/*
+ * IMPORTANT NOTE.
+ * This file contains XTOS parameters that may be modified
+ * according to needs. HOWEVER, any modifications are NOT
+ * supported. Handling of parameters other than the defaults
+ * provided in the original version of this file are for
+ * illustrative and educational purposes only. If you do
+ * change the parameters here-in (which requires rebuilding
+ * XTOS), please verify the resulting code extensively
+ * before even considering its use in production code.
+ *
+ * To rebuild XTOS, see instructions in the Xtensa System Software
+ * Reference Manual. The following sequence is no longer supported.
+ *
+ * cd <config_dir>/xtensa-elf/src/handlers
+ * xt-make clean
+ * xt-make
+ * xt-make install
+ *
+ * (Note: the last step installs the modified XTOS in *ALL*
+ * LSPs that normally include XTOS. You may prefer copying
+ * the generated files to your own custom LSP instead. Or
+ * better yet, also make a copy of all source files and maintain
+ * them somewhere completely separate -- which may require
+ * minor adjustments to the makefile.)
+ *
+ * PERFORMANCE TUNING:
+ * To slightly improve performance of interrupt dispatching,
+ * you can do some combination of the following:
+ * - change XTOS_SUBPRI to zero
+ * - change XTOS_SUBPRI_GROUPS to zero
+ * - change XTOS_SUBPRI_ORDER to XTOS_SPO_ZERO_HI
+ * - change XTOS_DEBUG_PC to zero
+ * - change XTOS_INT_FAIRNESS to zero
+ * - change XTOS_CNEST to zero
+ * There are non-trivial trade-offs in making such changes however,
+ * such as loss of support (see important note above), loss of
+ * interrupt scheduling fairness, loss of ability to traceback
+ * interrupt handlers across interrupted code when debugging them,
+ * loss of supported for nested C functions, etc.
+ */
+
+
+/*
+ * Lower LOCKLEVEL to XCHAL_EXCM_LEVEL for improved interrupt latency
+ * if you don't register C handlers for high-priority interrupts and your
+ * high-priority handlers don't touch INTENABLE nor virtual priorities.
+ *
+ * XTOS_LOCKLEVEL is less meaningful but still relevant if XEA2 and SUBPRI is zero,
+ * ie. if INTENABLE doesn't get virtualized (XTOS_VIRTUAL_INTENABLE not set);
+ * in this case, it is the interrupt level at which INTENABLE accesses are guarded,
+ * so that interrupt handlers up to this level can safely manipulate INTENABLE.
+ */
+#define XTOS_LOCKLEVEL XCHAL_NUM_INTLEVELS /* intlevel of INTENABLE register virtualization
+ (minimum is EXCM_LEVEL) */
+
+/*
+ * NOTE: the following four parameters (SUBPRI, SUBPRI_GROUPS, SUBPRI_ORDER, INT_FAIRNESS)
+ * are irrelevant and ignored for interrupt vectors to which only one interrupt is mapped.
+ */
+
+#define XTOS_SUBPRI 1 /* set to 0 if you don't need sub-prioritization
+ within level-one interrupts via software;
+ for XEA2 configs, this might improve performance of
+ certain sections of code, because INTENABLE register
+ virtualization becomes unnecessary in this case */
+
+/* Ignored unless SUBPRI set: */
+#define XTOS_SUBPRI_GROUPS 1 /* support selective grouping of interrupts at the same priority */
+
+#define XTOS_SUBPRI_ORDER XTOS_SPO_ZERO_LO /* one of XTOS_SPO_ZERO_LO, XTOS_SPO_ZERO_HI */
+
+/* Ignored if SUBPRI set but SUBPRI_GROUPS is not (single interrupt per subpri),
+ * or if single interrupt configured at level/vector: */
+#define XTOS_INT_FAIRNESS 1 /* disable round-robin/fifo scheduling of interrupt
+ handlers of a given level or sub-priority */
+
+
+#define XTOS_DEBUG_PC 1 /* enable nice stack traceback showing interrupted code
+ when debugging interrupt or exception handler;
+ not implemented for high-priority handlers, or
+ for call0 ABI */
+
+#define XTOS_CNEST 1 /* enable support for nested C functions
+ (save/restore nested C function call-chain pointer) */
+
+/* Current compilers only use ACC (not MRn) when MAC16 is enabled, so you can leave this 0 for performance: */
+#define XTOS_SAVE_ALL_MAC16 0 /* set to save/restore MAC16 MRn registers */
+
+/* Setting this might be useful to clear X's in hardware simulation a bit earlier, but
+ * should not be needed in production code: */
+#define XTOS_RESET_UNNEEDED 0 /* set to reset more registers than are really needed */
+
+#endif /* XTOS_PARAMS_H */
+
projects / open-ath9k-htc-firmware.git / blobdiff