280 lines
7.8 KiB
C
280 lines
7.8 KiB
C
/**
|
|
* \file
|
|
* <!--
|
|
* This file is part of BeRTOS.
|
|
*
|
|
* Bertos is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*
|
|
* As a special exception, you may use this file as part of a free software
|
|
* library without restriction. Specifically, if other files instantiate
|
|
* templates or use macros or inline functions from this file, or you compile
|
|
* this file and link it with other files to produce an executable, this
|
|
* file does not by itself cause the resulting executable to be covered by
|
|
* the GNU General Public License. This exception does not however
|
|
* invalidate any other reasons why the executable file might be covered by
|
|
* the GNU General Public License.
|
|
*
|
|
* Copyright 2008 Bernie Innocenti <bernie@codewiz.org>
|
|
* Copyright 2004, 2005, 2006, 2007, 2008 Develer S.r.l. (http://www.develer.com/)
|
|
* Copyright 2004 Giovanni Bajo
|
|
*
|
|
* -->
|
|
*
|
|
* \brief CPU-specific stack frame handling macros.
|
|
*
|
|
* These are mainly used by the portable part of the scheduler
|
|
* to work with the process stack frames.
|
|
*
|
|
* \author Giovanni Bajo <rasky@develer.com>
|
|
* \author Bernie Innocenti <bernie@codewiz.org>
|
|
* \author Stefano Fedrigo <aleph@develer.com>
|
|
* \author Francesco Sacchi <batt@develer.com>
|
|
*/
|
|
#ifndef CPU_FRAME_H
|
|
#define CPU_FRAME_H
|
|
|
|
#include <cpu/detect.h>
|
|
|
|
#include "cfg/cfg_arch.h" /* ARCH_EMUL */
|
|
#include <cfg/compiler.h> /* for uintXX_t */
|
|
|
|
#if CPU_X86
|
|
#if CPU_X86_32
|
|
#define CPU_SAVED_REGS_CNT 2
|
|
#elif CPU_X86_64
|
|
#define CPU_SAVED_REGS_CNT 8
|
|
#else
|
|
#error "unknown CPU"
|
|
#endif
|
|
#define CPU_STACK_GROWS_UPWARD 0
|
|
#define CPU_SP_ON_EMPTY_SLOT 0
|
|
|
|
#elif CPU_ARM
|
|
|
|
#define CPU_SAVED_REGS_CNT 8
|
|
#define CPU_STACK_GROWS_UPWARD 0
|
|
#define CPU_SP_ON_EMPTY_SLOT 0
|
|
|
|
#elif CPU_CM3
|
|
|
|
#define CPU_SAVED_REGS_CNT 8
|
|
#define CPU_STACK_GROWS_UPWARD 0
|
|
#define CPU_SP_ON_EMPTY_SLOT 0
|
|
|
|
#elif CPU_PPC
|
|
|
|
#define CPU_SAVED_REGS_CNT 1
|
|
#define CPU_STACK_GROWS_UPWARD 0
|
|
#define CPU_SP_ON_EMPTY_SLOT 1
|
|
|
|
#elif CPU_DSP56K
|
|
|
|
#define CPU_SAVED_REGS_CNT 8
|
|
#define CPU_STACK_GROWS_UPWARD 1
|
|
#define CPU_SP_ON_EMPTY_SLOT 0
|
|
|
|
#elif CPU_AVR
|
|
|
|
#define CPU_SAVED_REGS_CNT 18
|
|
#define CPU_STACK_GROWS_UPWARD 0
|
|
#define CPU_SP_ON_EMPTY_SLOT 1
|
|
|
|
#elif CPU_MSP430
|
|
|
|
#define CPU_SAVED_REGS_CNT 16
|
|
#define CPU_STACK_GROWS_UPWARD 1
|
|
#define CPU_SP_ON_EMPTY_SLOT 0
|
|
|
|
#else
|
|
#error No CPU_... defined.
|
|
#endif
|
|
|
|
#ifndef CPU_STACK_GROWS_UPWARD
|
|
#error CPU_STACK_GROWS_UPWARD should have been defined to either 0 or 1
|
|
#endif
|
|
|
|
#ifndef CPU_SP_ON_EMPTY_SLOT
|
|
#error CPU_SP_ON_EMPTY_SLOT should have been defined to either 0 or 1
|
|
#endif
|
|
|
|
/// Default for macro not defined in the right arch section
|
|
#ifndef CPU_REG_INIT_VALUE
|
|
#define CPU_REG_INIT_VALUE(reg) (reg)
|
|
#endif
|
|
|
|
/*
|
|
* Support stack handling peculiarities of a few CPUs.
|
|
*
|
|
* Most processors let their stack grow downward and
|
|
* keep SP pointing at the last pushed value.
|
|
*/
|
|
#if !CPU_STACK_GROWS_UPWARD
|
|
#if !CPU_SP_ON_EMPTY_SLOT
|
|
/* Most microprocessors (x86, m68k...) */
|
|
#define CPU_PUSH_WORD(sp, data) \
|
|
do { *--(sp) = (data); } while (0)
|
|
#define CPU_POP_WORD(sp) \
|
|
(*(sp)++)
|
|
#else
|
|
/* AVR insanity */
|
|
#define CPU_PUSH_WORD(sp, data) \
|
|
do { *(sp)-- = (data); } while (0)
|
|
#define CPU_POP_WORD(sp) \
|
|
(*++(sp))
|
|
#endif
|
|
|
|
#else /* CPU_STACK_GROWS_UPWARD */
|
|
|
|
#if !CPU_SP_ON_EMPTY_SLOT
|
|
/* DSP56K and other weirdos */
|
|
#define CPU_PUSH_WORD(sp, data) \
|
|
do { *++(sp) = (cpu_stack_t)(data); } while (0)
|
|
#define CPU_POP_WORD(sp) \
|
|
(*(sp)--)
|
|
#else
|
|
#error I bet you cannot find a CPU like this
|
|
#endif
|
|
#endif
|
|
|
|
|
|
#if CPU_DSP56K
|
|
/*
|
|
* DSP56k pushes both PC and SR to the stack in the JSR instruction, but
|
|
* RTS discards SR while returning (it does not restore it). So we push
|
|
* 0 to fake the same context.
|
|
*/
|
|
#define CPU_PUSH_CALL_FRAME(sp, func) \
|
|
do { \
|
|
CPU_PUSH_WORD((sp), (func)); \
|
|
CPU_PUSH_WORD((sp), 0x100); \
|
|
} while (0);
|
|
|
|
#elif CPU_CM3
|
|
|
|
#if CONFIG_KERN_PREEMPT
|
|
INLINE void cm3_preempt_switch_context(cpu_stack_t **new_sp, cpu_stack_t **old_sp)
|
|
{
|
|
register cpu_stack_t **__new_sp asm ("r0") = new_sp;
|
|
register cpu_stack_t **__old_sp asm ("r1") = old_sp;
|
|
|
|
asm volatile ("svc #0"
|
|
: : "r"(__new_sp), "r"(__old_sp) : "memory", "cc");
|
|
}
|
|
#define asm_switch_context cm3_preempt_switch_context
|
|
|
|
#define CPU_CREATE_NEW_STACK(stack) \
|
|
do { \
|
|
size_t i; \
|
|
/* Initialize process stack frame */ \
|
|
CPU_PUSH_WORD((stack), 0x01000000); /* xPSR */ \
|
|
CPU_PUSH_WORD((stack), (cpu_stack_t)proc_entry); /* pc */ \
|
|
CPU_PUSH_WORD((stack), 0); /* lr */ \
|
|
CPU_PUSH_WORD((stack), 0); /* ip */ \
|
|
CPU_PUSH_WORD((stack), 0); /* r3 */ \
|
|
CPU_PUSH_WORD((stack), 0); /* r2 */ \
|
|
CPU_PUSH_WORD((stack), 0); /* r1 */ \
|
|
CPU_PUSH_WORD((stack), 0); /* r0 */ \
|
|
CPU_PUSH_WORD((stack), 0xfffffffd); /* lr_exc */ \
|
|
/* Push a clean set of CPU registers for asm_switch_context() */ \
|
|
for (i = 0; i < CPU_SAVED_REGS_CNT; i++) \
|
|
CPU_PUSH_WORD(stack, CPU_REG_INIT_VALUE(i)); \
|
|
CPU_PUSH_WORD(stack, IRQ_PRIO_DISABLED); \
|
|
} while (0)
|
|
|
|
#endif /* CONFIG_KERN_PREEMPT */
|
|
|
|
#elif CPU_AVR
|
|
/*
|
|
* On AVR, addresses are pushed into the stack as little-endian, while
|
|
* memory accesses are big-endian (actually, it's a 8-bit CPU, so there is
|
|
* no natural endianess).
|
|
*/
|
|
#define CPU_PUSH_CALL_FRAME(sp, func) \
|
|
do { \
|
|
uint16_t funcaddr = (uint16_t)(func); \
|
|
CPU_PUSH_WORD((sp), funcaddr); \
|
|
CPU_PUSH_WORD((sp), funcaddr>>8); \
|
|
} while (0)
|
|
|
|
/*
|
|
* If the kernel is in idle-spinning, the processor executes:
|
|
*
|
|
* IRQ_ENABLE;
|
|
* CPU_IDLE;
|
|
* IRQ_DISABLE;
|
|
*
|
|
* IRQ_ENABLE is translated in asm as "sei" and IRQ_DISABLE as "cli".
|
|
* We could define CPU_IDLE to expand to none, so the resulting
|
|
* asm code would be:
|
|
*
|
|
* sei;
|
|
* cli;
|
|
*
|
|
* But Atmel datasheet states:
|
|
* "When using the SEI instruction to enable interrupts,
|
|
* the instruction following SEI will be executed *before*
|
|
* any pending interrupts", so "cli" is executed before any
|
|
* pending interrupt with the result that IRQs will *NOT*
|
|
* be enabled!
|
|
* To ensure that IRQ will run a NOP is required.
|
|
*/
|
|
#define CPU_IDLE NOP
|
|
|
|
#elif CPU_PPC
|
|
|
|
#define CPU_PUSH_CALL_FRAME(sp, func) \
|
|
do { \
|
|
CPU_PUSH_WORD((sp), (cpu_stack_t)(func)); /* LR -> 8(SP) */ \
|
|
CPU_PUSH_WORD((sp), 0); /* CR -> 4(SP) */ \
|
|
} while (0)
|
|
|
|
#endif
|
|
|
|
#ifndef CPU_PUSH_CALL_FRAME
|
|
#define CPU_PUSH_CALL_FRAME(sp, func) \
|
|
CPU_PUSH_WORD((sp), (cpu_stack_t)(func))
|
|
#endif
|
|
|
|
/**
|
|
* \def CPU_IDLE
|
|
*
|
|
* \brief Invoked by the scheduler to stop the CPU when idle.
|
|
*
|
|
* This hook can be redefined to put the CPU in low-power mode, or to
|
|
* profile system load with an external strobe, or to save CPU cycles
|
|
* in hosted environments such as emulators.
|
|
*/
|
|
#ifndef CPU_IDLE
|
|
#define CPU_IDLE PAUSE
|
|
#endif /* !CPU_IDLE */
|
|
|
|
/**
|
|
* Default macro for creating a new Process stack
|
|
*/
|
|
#ifndef CPU_CREATE_NEW_STACK
|
|
|
|
#define CPU_CREATE_NEW_STACK(stack) \
|
|
do { \
|
|
size_t i; \
|
|
/* Initialize process stack frame */ \
|
|
CPU_PUSH_CALL_FRAME(stack, proc_entry); \
|
|
/* Push a clean set of CPU registers for asm_switch_context() */ \
|
|
for (i = 0; i < CPU_SAVED_REGS_CNT; i++) \
|
|
CPU_PUSH_WORD(stack, CPU_REG_INIT_VALUE(i)); \
|
|
} while (0)
|
|
#endif
|
|
|
|
#endif /* CPU_ATTR_H */
|