rt-thread/libcpu/nds32/cpuport.c

203 lines
6.7 KiB
C

/*
* File : cpuport.c
* This program 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 Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Change Logs:
* Date Author Notes
* 2017-08-25 Archer first version
*/
#include <rtthread.h>
#include "nds32.h"
/*
* Initialise the stack of a task to look exactly as if a call to
* SAVE_CONTEXT had been called.
*
* See header file for description.
*
*
* Stack Layout:
* High |-----------------|
* | $R5 |
* |-----------------|
* | . |
* | . |
* |-----------------|
* | $R0 |
* |-----------------|
* | $R30 (LP) |
* |-----------------|
* | $R29 (GP) |
* |-----------------|
* | $R28 (FP) |
* |-----------------|
* | $R15 $R27 |
* |-----------------|
* | $R10 $R26 |
* |-----------------|
* | . |
* | . |
* |-----------------|
* | $R6 |
* |-----------------|
* | $IFC_LP | (Option)
* |-----------------|
* | $LC/$LE/$LB | (Option)
* | (ZOL) |
* |-----------------|
* | $IPSW |
* |-----------------|
* | $IPC |
* |-----------------|
* | Dummy word | (Option, only exist when IFC & ZOL both configured)
* |-----------------|
* | $FPU | (Option)
* |-----------------|
* Low
*
*/
struct stack_frame
{
rt_uint32_t topOfStack[34];
};
/* flag in interrupt handling */
rt_uint32_t rt_interrupt_from_thread, rt_interrupt_to_thread;
rt_uint32_t rt_thread_switch_interrupt_flag;
/* exception hook */
static rt_err_t (*rt_exception_hook)(void *context) = RT_NULL;
rt_base_t rt_hw_interrupt_disable(void)
{
rt_base_t level = __nds32__mfsr(NDS32_SR_PSW);
GIE_DISABLE();
return level;
}
void rt_hw_interrupt_enable(rt_base_t level)
{
if (level & PSW_mskGIE)
GIE_ENABLE();
}
/* For relax support, must initial $gp at task init*/
extern uint32_t _SDA_BASE_ __attribute__ ((weak));
/**************************************************************
* This function will initialize thread stack
*
* @param tentry the entry of thread
* @param parameter the parameter of entry
* @param stack_addr the beginning stack address
* @param texit the function will be called when thread exit
*
* @return stack address
**************************************************************/
rt_uint8_t *rt_hw_stack_init(void *tentry,
void *parameter,
rt_uint8_t *stack_addr,
void *texit)
{
rt_int32_t i;
rt_uint32_t *pxTopOfStack;
pxTopOfStack = (rt_uint32_t *)RT_ALIGN_DOWN((rt_uint32_t)stack_addr, 4);
/* Simulate the stack frame as it would be created by a context switch */
/* R0 ~ R5 registers */
for (i = 5; i >= 1; i--) /* R5, R4, R3, R2 and R1. */
*--pxTopOfStack = (rt_uint32_t)0x01010101UL * i;
*--pxTopOfStack = (rt_uint32_t)parameter; /* R0 : Argument */
/* R6 ~ R30 registers */
*--pxTopOfStack = (rt_uint32_t)texit; /* R30: $LP */
*--pxTopOfStack = (rt_uint32_t)&_SDA_BASE_; /* R29: $GP */
*--pxTopOfStack = (rt_uint32_t)0x2828282828; /* R28: $FP */
#ifdef __NDS32_REDUCE_REGS__
*--pxTopOfStack = (rt_uint32_t)0x1515151515; /* R15 */
for (i = 10; i >= 6; i--) /* R10 ~ R6 */
*--pxTopOfStack = (rt_uint32_t)0x01010101UL * i;
#else
for (i = 27; i >= 6; i--) /* R27 ~ R6 */
*--pxTopOfStack = (rt_uint32_t)0x01010101UL * i;
#endif
/* IFC system register */
#ifdef __TARGET_IFC_EXT
*--pxTopOfStack = (rt_uint32_t)0x0; /* $IFC_LP */
#endif
/* ZOL system registers */
#ifdef __TARGET_ZOL_EXT
*--pxTopOfStack = (rt_uint32_t)0x0; /* $LC */
*--pxTopOfStack = (rt_uint32_t)0x0; /* $LE */
*--pxTopOfStack = (rt_uint32_t)0x0; /* $LB */
#endif
/* IPSW and IPC system registers */
/* Default IPSW: enable GIE, set CPL to 7, clear IFCON */
i = (__nds32__mfsr(NDS32_SR_PSW) | PSW_mskGIE | PSW_mskCPL) & ~PSW_mskIFCON;
*--pxTopOfStack = (rt_uint32_t)i; /* $IPSW */
*--pxTopOfStack = (rt_uint32_t)tentry; /* $IPC */
/* Dummy word for 8-byte stack alignment */
#if defined(__TARGET_IFC_EXT) && defined(__TARGET_ZOL_EXT)
*--pxTopOfStack = (rt_uint32_t)0xFFFFFFFF; /* Dummy */
#endif
/* FPU registers */
#ifdef __TARGET_FPU_EXT
for (i = 0; i < FPU_REGS; i++)
*--pxTopOfStack = (rt_uint32_t)0x0; /* FPU */
#endif
return (rt_uint8_t *)pxTopOfStack;
}
/**
* This function set the hook, which is invoked on fault exception handling.
*
* @param exception_handle the exception handling hook function.
*/
void rt_hw_exception_install(rt_err_t (*exception_handle)(void* context))
{
rt_exception_hook = exception_handle;
}
#ifdef RT_USING_CPU_FFS
/**
* This function finds the first bit set (beginning with the least significant bit)
* in value and return the index of that bit.
*
* Bits are numbered starting at 1 (the least significant bit). A return value of
* zero from any of these functions means that the argument was zero.
*
* @return return the index of the first bit set. If value is 0, then this function
* shall return 0.
*/
#if defined(__GNUC__)
int __rt_ffs(int value)
{
return __builtin_ffs(value);
}
#endif
#endif