/* * Copyright (C) 2001-2005 by egnite Software GmbH. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the copyright holders nor the names of * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * For additional information see http://www.ethernut.de/ * */ /*! * \file arch/avr/os/context_gcc.c * \brief Context switching ported to AVR GCC. * * \verbatim File version $Id: context_gcc.c 4937 2013-01-22 11:38:42Z haraldkipp $ \endverbatim */ #include #include #include #include #include #include /* Support for separate irq stack only for avr-gcc */ #include #ifdef NUTDEBUG #include #endif /*! * \addtogroup xgNutArchAvrOsContextGcc GCC Context Switching for AVR CPUs * \ingroup xgNutArchAvrOs * \brief Thread context switching for avr-gcc. */ /*@{*/ #ifdef IRQSTACK_SIZE /*! * \brief Decrement value for thread's stack size, if separate irq stack is used. * * If separate irq stack is enabled (avr-gcc only), the initial parameter * 'stacksize' in function 'NutThreadCreate' is decremented by this value, if the * remaining stack size is 128 bytes or greater. * */ uint16_t _irqstackdec = 128; #endif /* #ifdef IRQSTACK_SIZE */ /*! * \brief AVR GCC context switch frame layout. * * This is the layout of the stack after a thread's context has been * switched-out. */ typedef struct { uint8_t csf_r29; uint8_t csf_r28; uint8_t csf_r17; uint8_t csf_r16; uint8_t csf_r15; uint8_t csf_r14; uint8_t csf_r13; uint8_t csf_r12; uint8_t csf_r11; uint8_t csf_r10; uint8_t csf_r9; uint8_t csf_r8; uint8_t csf_r7; uint8_t csf_r6; uint8_t csf_r5; uint8_t csf_r4; uint8_t csf_r3; uint8_t csf_r2; #ifdef __AVR_3_BYTE_PC__ uint8_t csf_pcex; #endif uint8_t csf_pchi; uint8_t csf_pclo; } SWITCHFRAME; /*! * \brief Thread entry frame layout. * * This is the stack layout being build to enter a new thread. */ typedef struct { uint8_t cef_arghi; uint8_t cef_arglo; uint8_t cef_rampz; uint8_t cef_sreg; uint8_t cef_r1; #ifdef __AVR_3_BYTE_PC__ uint8_t cef_pcex; #endif uint8_t cef_pchi; uint8_t cef_pclo; } ENTERFRAME; #define LONG_PTR_P(lp, mem_p) \ __asm__ __volatile__("ldi %A0, lo8("#mem_p ")" "\n\t" \ "ldi %B0, hi8("#mem_p ")" "\n\t" \ "ldi %C0, hh8("#mem_p ")" "\n\t" \ "clr %D0" \ :"=d" (lp)) /* * This code is executed when entering a thread. */ static void NutThreadEntry(void) NUT_NAKED_FUNC; static void NutThreadEntry(void) { __asm__ __volatile__("pop r25" "\n\t" /* first parameter hi-byte */ "pop r24" "\n\t" /* first parameter lo-byte */ "pop __tmp_reg__" "\n\t" /* Get RAMPZ */ "out %0, __tmp_reg__" "\n\t" /* Restore RAMPZ */ "pop __tmp_reg__" "\n\t" /* Get SREG */ "out %1, __tmp_reg__" "\n\t" /* Restore SREG */ "pop __zero_reg__" "\n\t" /* Zero register */ "reti" "\n\t" /* enables interrupts */ ::"I" _SFR_IO_ADDR(RAMPZ), "I" _SFR_IO_ADDR(SREG) ); } void NutThreadSwitch(void) NUT_PREVENT_INLINE NUT_NAKED_FUNC; void NutThreadSwitch(void) { /* * Save all CPU registers. */ asm volatile ("push r2" "\n\t" /* */ "push r3" "\n\t" /* */ "push r4" "\n\t" /* */ "push r5" "\n\t" /* */ "push r6" "\n\t" /* */ "push r7" "\n\t" /* */ "push r8" "\n\t" /* */ "push r9" "\n\t" /* */ "push r10" "\n\t" /* */ "push r11" "\n\t" /* */ "push r12" "\n\t" /* */ "push r13" "\n\t" /* */ "push r14" "\n\t" /* */ "push r15" "\n\t" /* */ "push r16" "\n\t" /* */ "push r17" "\n\t" /* */ "push r28" "\n\t" /* */ "push r29" "\n\t" /* */ "in %A0, %1" "\n\t" /* */ "in %B0, %2" "\n\t" /* */ :"=r" (runningThread->td_sp) /* */ :"I" _SFR_IO_ADDR(SPL), /* */ "I" _SFR_IO_ADDR(SPH) /* */ ); /* * This defines a global label, which may be called * as an entry point into this function. */ asm volatile (".global thread_start\n" /* */ "thread_start:\n\t"::); /* * Reload CPU registers from the thread on top of the run queue. */ runningThread = runQueue; runningThread->td_state = TDS_RUNNING; asm volatile ("out %1, %A0" "\n\t" /* */ "out %2, %B0" "\n\t" /* */ "pop r29" "\n\t" /* */ "pop r28" "\n\t" /* */ "pop r17" "\n\t" /* */ "pop r16" "\n\t" /* */ "pop r15" "\n\t" /* */ "pop r14" "\n\t" /* */ "pop r13" "\n\t" /* */ "pop r12" "\n\t" /* */ "pop r11" "\n\t" /* */ "pop r10" "\n\t" /* */ "pop r9" "\n\t" /* */ "pop r8" "\n\t" /* */ "pop r7" "\n\t" /* */ "pop r6" "\n\t" /* */ "pop r5" "\n\t" /* */ "pop r4" "\n\t" /* */ "pop r3" "\n\t" /* */ "pop r2" "\n\t" /* */ "ret" "\n\t" /* */ ::"r" (runningThread->td_sp), /* */ "I" _SFR_IO_ADDR(SPL), /* */ "I" _SFR_IO_ADDR(SPH) /* */ ); } HANDLE NutThreadCreate(char * name, void (*fn) (void *), void *arg, size_t stackSize) { uint8_t *threadMem; SWITCHFRAME *sf; ENTERFRAME *ef; NUTTHREADINFO *td; #ifdef IRQSTACK_SIZE if (stackSize > _irqstackdec + 128) stackSize -= _irqstackdec; #endif /* * Allocate stack and thread info structure in one block. */ if ((threadMem = NutStackAlloc(stackSize + sizeof(NUTTHREADINFO))) == 0) { return 0; } td = (NUTTHREADINFO *) (threadMem + stackSize); ef = (ENTERFRAME *) ((uint16_t) td - sizeof(ENTERFRAME)); sf = (SWITCHFRAME *) ((uint16_t) ef - sizeof(SWITCHFRAME)); memcpy(td->td_name, name, sizeof(td->td_name) - 1); td->td_name[sizeof(td->td_name) - 1] = 0; td->td_sp = (uint16_t) sf - 1; td->td_memory = threadMem; /* * Set predefined values at the stack bottom. May be used to detect * stack overflows. */ #if defined(NUTDEBUG_CHECK_STACKMIN) || defined(NUTDEBUG_CHECK_STACK) { uint32_t *fip = (uint32_t *)threadMem; while (fip < (uint32_t *)sf) { *fip++ = DEADBEEF; } } #else *((uint32_t *) threadMem) = DEADBEEF; *((uint32_t *) (threadMem + 4)) = DEADBEEF; *((uint32_t *) (threadMem + 8)) = DEADBEEF; *((uint32_t *) (threadMem + 12)) = DEADBEEF; #endif td->td_priority = 64; /* * Setup entry frame to simulate C function entry. */ #ifdef __AVR_3_BYTE_PC__ ef->cef_pcex = 0; #endif ef->cef_pchi = (uint8_t) (((uint16_t) fn) >> 8); ef->cef_pclo = (uint8_t) (((uint16_t) fn) & 0xff); ef->cef_sreg = 0x80; ef->cef_rampz = 0; ef->cef_r1 = 0; ef->cef_arglo = (uint8_t) (((uint16_t) arg) & 0xff); ef->cef_arghi = (uint8_t) (((uint16_t) arg) >> 8); #ifdef __AVR_3_BYTE_PC__ sf->csf_pcex = 0; #endif sf->csf_pchi = (uint8_t) (((uint16_t) NutThreadEntry) >> 8); sf->csf_pclo = (uint8_t) (((uint16_t) NutThreadEntry) & 0xff); /* * Insert into the thread list and the run queue. */ td->td_next = nutThreadList; nutThreadList = td; td->td_state = TDS_READY; td->td_timer = 0; td->td_queue = 0; #ifdef NUTDEBUG if (__os_trf) fprintf(__os_trs, "Cre<%04x>", (uintptr_t) td); #endif NutThreadAddPriQueue(td, (NUTTHREADINFO **) & runQueue); #ifdef NUTDEBUG if (__os_trf) { NutDumpThreadList(__os_trs); //NutDumpThreadQueue(__os_trs, runQueue); } #endif /* * If no thread is active, switch to new thread. */ if (runningThread == 0) { NutEnterCritical(); asm volatile ("rjmp thread_start\n\t"::); /* we will never come back here .. */ } /* * If current context is not in front of * the run queue (highest priority), then * switch to the thread in front. */ if (runningThread != runQueue) { runningThread->td_state = TDS_READY; #ifdef NUTDEBUG if (__os_trf) fprintf(__os_trs, "New<%04x %04x>", (uintptr_t) runningThread, (uintptr_t) runQueue); #endif NutEnterCritical(); NutThreadSwitch(); NutExitCritical(); } return td; } /*@}*/