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freertos_risc_v_chip_specific_extensions.h
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freertos_risc_v_chip_specific_extensions.h
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/*
* FreeRTOS Kernel V10.4.3
* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and t
o permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
* 1 tab == 4 spaces!
*/
/*
* The FreeRTOS kernel's RISC-V port is split between the the code that is
* common across all currently supported RISC-V chips (implementations of the
* RISC-V ISA), and code that tailors the port to a specific RISC-V chip:
*
* + FreeRTOS\Source\portable\GCC\RISC-V-RV32\portASM.S contains the code that
* is common to all currently supported RISC-V chips. There is only one
* portASM.S file because the same file is built for all RISC-V target chips.
*
* + Header files called freertos_risc_v_chip_specific_extensions.h contain the
* code that tailors the FreeRTOS kernel's RISC-V port to a specific RISC-V
* chip. There are multiple freertos_risc_v_chip_specific_extensions.h files
* as there are multiple RISC-V chip implementations.
*
* !!!NOTE!!!
* TAKE CARE TO INCLUDE THE CORRECT freertos_risc_v_chip_specific_extensions.h
* HEADER FILE FOR THE CHIP IN USE. This is done using the assembler's (not the
* compiler's!) include path. For example, if the chip in use includes a core
* local interrupter (CLINT) and does not include any chip specific register
* extensions then add the path below to the assembler's include path:
* FreeRTOS\Source\portable\GCC\RISC-V-RV32\chip_specific_extensions\RV32I_CLINT_no_extensions
*
*/
/*
* This freertos_risc_v_chip_specific_extensions.h is for use with Pulpino Ri5cy
* devices, developed and tested using the Vega board RV32M1RM.
*/
#ifndef __FREERTOS_RISC_V_EXTENSIONS_H__
#define __FREERTOS_RISC_V_EXTENSIONS_H__
#define portasmHAS_MTIME 0
/* Constants to define the additional registers found on the Pulpino RI5KY. */
#define lpstart0 0x7b0
#define lpend0 0x7b1
#define lpcount0 0x7b2
#define lpstart1 0x7b4
#define lpend1 0x7b5
#define lpcount1 0x7b6
/* Six additional registers to save and restore, as per the #defines above. */
#define portasmADDITIONAL_CONTEXT_SIZE 6 /* Must be even number on 32-bit cores. */
/* Save additional registers found on the Pulpino. */
.macro portasmSAVE_ADDITIONAL_REGISTERS
addi sp, sp, -(portasmADDITIONAL_CONTEXT_SIZE * portWORD_SIZE) /* Make room for the additional registers. */
csrr t0, lpstart0 /* Load additional registers into accessible temporary registers. */
csrr t1, lpend0
csrr t2, lpcount0
csrr t3, lpstart1
csrr t4, lpend1
csrr t5, lpcount1
sw t0, 1 * portWORD_SIZE( sp )
sw t1, 2 * portWORD_SIZE( sp )
sw t2, 3 * portWORD_SIZE( sp )
sw t3, 4 * portWORD_SIZE( sp )
sw t4, 5 * portWORD_SIZE( sp )
sw t5, 6 * portWORD_SIZE( sp )
.endm
/* Restore the additional registers found on the Pulpino. */
.macro portasmRESTORE_ADDITIONAL_REGISTERS
lw t0, 1 * portWORD_SIZE( sp ) /* Load additional registers into accessible temporary registers. */
lw t1, 2 * portWORD_SIZE( sp )
lw t2, 3 * portWORD_SIZE( sp )
lw t3, 4 * portWORD_SIZE( sp )
lw t4, 5 * portWORD_SIZE( sp )
lw t5, 6 * portWORD_SIZE( sp )
csrw lpstart0, t0
csrw lpend0, t1
csrw lpcount0, t2
csrw lpstart1, t3
csrw lpend1, t4
csrw lpcount1, t5
addi sp, sp, (portasmADDITIONAL_CONTEXT_SIZE * portWORD_SIZE )/* Remove space added for additional registers. */
.endm
#endif /* __FREERTOS_RISC_V_EXTENSIONS_H__ */