feat(esp8266): Add xtensa source to esp8266 component

components/esp8266/source/xtensa_init.c

@@ -0,0 +1,55 @@
+/*******************************************************************************
+Copyright (c) 2006-2009 by Tensilica Inc.  ALL RIGHTS RESERVED.
+These coded instructions, statements, and computer programs are the
+copyrighted works and confidential proprietary information of Tensilica Inc.
+They may not be modified, copied, reproduced, distributed, or disclosed to
+third parties in any manner, medium, or form, in whole or in part, without
+the prior written consent of Tensilica Inc.
+--------------------------------------------------------------------------------
+
+        XTENSA INITIALIZATION ROUTINES CODED IN C
+
+This header is a place to put miscellaneous Xtensa RTOS-generic initialization 
+functions that are implemented in C.
+
+This header contains definitions and macros for use primarily by Xtensa
+RTOS assembly coded source files. It includes and uses the Xtensa hardware
+abstraction layer (HAL) to deal with config specifics. It may also be
+included in C source files.
+
+*******************************************************************************/
+
+#ifndef XTENSA_INIT_H
+#define XTENSA_INIT_H
+
+#ifdef XT_BOARD
+#include    <xtensa/xtbsp.h>
+#endif
+
+#include    "freertos/xtensa_rtos.h"
+
+
+#ifdef XT_RTOS_TIMER_INT
+#ifndef XT_CLOCK_FREQ
+
+unsigned _xt_tick_divisor = 0;  /* cached number of cycles per tick */
+
+/*
+Compute and initialize at run-time the tick divisor (the number of 
+processor clock cycles in an RTOS tick, used to set the tick timer).
+Called when the processor clock frequency is not known at compile-time.
+*/
+void ICACHE_FLASH_ATTR
+_xt_tick_divisor_init(void)
+{
+    #ifdef XT_BOARD
+    _xt_tick_divisor = xtbsp_clock_freq_hz() / XT_TICK_PER_SEC;
+    #else
+    #error "No way to obtain processor clock frequency"
+    #endif  /* XT_BOARD */
+}
+
+#endif /* XT_CLOCK_FREQ */
+#endif /* XT_RTOS_TIMER_INT */
+
+#endif /* XTENSA_INIT_H */