99 lines
2.2 KiB
ArmAsm
99 lines
2.2 KiB
ArmAsm
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/*
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* Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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.syntax unified
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.cpu cortex-m0plus
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.thumb
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#include "pico/asm_helper.S"
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__pre_init __aeabi_mem_init, 00001
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.macro mem_section name
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#if PICO_MEM_IN_RAM
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.section RAM_SECTION_NAME(\name), "ax"
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#else
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.section SECTION_NAME(\name), "ax"
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#endif
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.endm
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.equ MEMSET, 0
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.equ MEMCPY, 4
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.equ MEMSET4, 8
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.equ MEMCPY4, 12
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.equ MEM_FUNC_COUNT, 4
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# NOTE: All code sections are placed in RAM (at the expense of some veneer cost for calls from flash) because
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# otherwise code using basic c division operators will require XIP flash access.
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.section .data.aeabi_mem_funcs
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.global aeabi_mem_funcs, aeabi_mem_funcs_end
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.align 2
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aeabi_mem_funcs:
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.word rom_table_code('M','S')
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.word rom_table_code('M','C')
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.word rom_table_code('S','4')
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.word rom_table_code('C','4')
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aeabi_mem_funcs_end:
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.section .text
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regular_func __aeabi_mem_init
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ldr r0, =aeabi_mem_funcs
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movs r1, #MEM_FUNC_COUNT
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ldr r3, =rom_funcs_lookup
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bx r3
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# lump them both together because likely both to be used, in which case doing so saves 1 word
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# and it only costs 1 word if not
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// Note from Run-time ABI for the ARM architecture 4.3.4:
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// If there is an attached device with efficient memory copying or clearing operations
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// (such as a DMA engine), its device supplement specifies whether it may be used in
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// implementations of these functions and what effect such use has on the device’s state.
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mem_section aeabi_memset_memcpy
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wrapper_func __aeabi_memset
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// args are backwards
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eors r0, r1
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eors r1, r0
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eors r0, r1
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ldr r3, =aeabi_mem_funcs
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ldr r3, [r3, #MEMSET]
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bx r3
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wrapper_func __aeabi_memset4
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wrapper_func __aeabi_memset8
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// args are backwards
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eors r0, r1
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eors r1, r0
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eors r0, r1
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ldr r3, =aeabi_mem_funcs
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ldr r3, [r3, #MEMSET4]
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bx r3
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wrapper_func __aeabi_memcpy4
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wrapper_func __aeabi_memcpy8
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ldr r3, =aeabi_mem_funcs
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ldr r3, [r3, #MEMCPY4]
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bx r3
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mem_section memset
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wrapper_func memset
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ldr r3, =aeabi_mem_funcs
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ldr r3, [r3, #MEMSET]
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bx r3
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mem_section memcpy
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wrapper_func __aeabi_memcpy
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wrapper_func memcpy
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ldr r3, =aeabi_mem_funcs
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ldr r3, [r3, #MEMCPY]
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bx r3
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