zephyr/arch/arc/core/prep_c.c

127 lines
2.7 KiB
C

/*
* Copyright (c) 2014 Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief Full C support initialization
*
*
* Initialization of full C support: zero the .bss, copy the .data if XIP,
* call _Cstart().
*
* Stack is available in this module, but not the global data/bss until their
* initialization is performed.
*/
#include <zephyr/types.h>
#include <toolchain.h>
#include <linker/linker-defs.h>
#include <arch/arc/v2/aux_regs.h>
#include <kernel_structs.h>
#include <kernel_internal.h>
/* XXX - keep for future use in full-featured cache APIs */
#if 0
/**
*
* @brief Disable the i-cache if present
*
* For those ARC CPUs that have a i-cache present,
* invalidate the i-cache and then disable it.
*
* @return N/A
*/
static void disable_icache(void)
{
unsigned int val;
val = _arc_v2_aux_reg_read(_ARC_V2_I_CACHE_BUILD);
val &= 0xff; /* version field */
if (val == 0) {
return; /* skip if i-cache is not present */
}
_arc_v2_aux_reg_write(_ARC_V2_IC_IVIC, 0);
__asm__ __volatile__ ("nop");
_arc_v2_aux_reg_write(_ARC_V2_IC_CTRL, 1);
}
/**
*
* @brief Invalidate the data cache if present
*
* For those ARC CPUs that have a data cache present,
* invalidate the data cache.
*
* @return N/A
*/
static void invalidate_dcache(void)
{
unsigned int val;
val = _arc_v2_aux_reg_read(_ARC_V2_D_CACHE_BUILD);
val &= 0xff; /* version field */
if (val == 0) {
return; /* skip if d-cache is not present */
}
_arc_v2_aux_reg_write(_ARC_V2_DC_IVDC, 1);
}
#endif
/**
*
* @brief Adjust the vector table base
*
* Set the vector table base if the value found in the
* _ARC_V2_IRQ_VECT_BASE auxiliary register is different from the
* _VectorTable known by software. It is important to do this very early
* so that exception vectors can be handled.
*
* @return N/A
*/
static void adjust_vector_table_base(void)
{
#ifdef CONFIG_ARC_HAS_SECURE
#undef _ARC_V2_IRQ_VECT_BASE
#define _ARC_V2_IRQ_VECT_BASE _ARC_V2_IRQ_VECT_BASE_S
#endif
extern struct vector_table _VectorTable;
unsigned int vbr;
/* if the compiled-in vector table is different
* from the base address known by the ARC CPU,
* set the vector base to the compiled-in address.
*/
vbr = _arc_v2_aux_reg_read(_ARC_V2_IRQ_VECT_BASE);
vbr &= 0xfffffc00;
if (vbr != (unsigned int)&_VectorTable) {
_arc_v2_aux_reg_write(_ARC_V2_IRQ_VECT_BASE,
(unsigned int)&_VectorTable);
}
}
extern FUNC_NORETURN void _Cstart(void);
/**
*
* @brief Prepare to and run C code
*
* This routine prepares for the execution of and runs C code.
*
* @return N/A
*/
void _PrepC(void)
{
_icache_setup();
adjust_vector_table_base();
_bss_zero();
_data_copy();
_Cstart();
CODE_UNREACHABLE;
}