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