simmel-bootloader/segger/thumb_crt0.s
2020-03-24 21:59:53 +07:00

421 lines
8.2 KiB
ArmAsm

// SEGGER Embedded Studio, runtime support.
//
// Copyright (c) 2014-2017 SEGGER Microcontroller GmbH & Co KG
// Copyright (c) 2001-2017 Rowley Associates Limited.
//
// This file may be distributed under the terms of the License Agreement
// provided with this software.
//
// THIS FILE IS PROVIDED AS IS WITH NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
//
// Preprocessor Definitions
// ------------------------
// APP_ENTRY_POINT
//
// Defines the application entry point function, if undefined this setting
// defaults to "main".
//
// INITIALIZE_STACK
//
// If defined, the contents of the stack will be initialized to a the
// value 0xCC.
//
// INITIALIZE_SECONDARY_SECTIONS
//
// If defined, the .data2, .text2, .rodata2 and .bss2 sections will be initialized.
//
// INITIALIZE_TCM_SECTIONS
//
// If defined, the .data_tcm, .text_tcm, .rodata_tcm and .bss_tcm sections
// will be initialized.
//
// INITIALIZE_USER_SECTIONS
//
// If defined, the function InitializeUserMemorySections will be called prior
// to entering main in order to allow the user to initialize any user defined
// memory sections.
//
// FULL_LIBRARY
//
// If defined then
// - argc, argv are setup by the debug_getargs.
// - the exit symbol is defined and executes on return from main.
// - the exit symbol calls destructors, atexit functions and then debug_exit.
//
// If not defined then
// - argc and argv are zero.
// - the exit symbol is defined, executes on return from main and loops
//
#ifndef APP_ENTRY_POINT
#define APP_ENTRY_POINT main
#endif
#ifndef ARGSSPACE
#define ARGSSPACE 128
#endif
.syntax unified
.global _start
.extern APP_ENTRY_POINT
.global exit
.weak exit
#ifdef INITIALIZE_USER_SECTIONS
.extern InitializeUserMemorySections
#endif
.section .init, "ax"
.code 16
.align 2
.thumb_func
_start:
/* Set up main stack if size > 0 */
ldr r1, =__stack_end__
ldr r0, =__stack_start__
subs r2, r1, r0
beq 1f
#ifdef __ARM_EABI__
movs r2, #0x7
bics r1, r2
#endif
mov sp, r1
#ifdef INITIALIZE_STACK
movs r2, #0xCC
ldr r0, =__stack_start__
bl memory_set
#endif
1:
/* Set up process stack if size > 0 */
ldr r1, =__stack_process_end__
ldr r0, =__stack_process_start__
subs r2, r1, r0
beq 1f
#ifdef __ARM_EABI__
movs r2, #0x7
bics r1, r2
#endif
msr psp, r1
movs r2, #2
msr control, r2
#ifdef INITIALIZE_STACK
movs r2, #0xCC
bl memory_set
#endif
1:
/* Copy initialized memory sections into RAM (if necessary). */
ldr r0, =__data_load_start__
ldr r1, =__data_start__
ldr r2, =__data_end__
bl memory_copy
ldr r0, =__text_load_start__
ldr r1, =__text_start__
ldr r2, =__text_end__
bl memory_copy
ldr r0, =__fast_load_start__
ldr r1, =__fast_start__
ldr r2, =__fast_end__
bl memory_copy
ldr r0, =__ctors_load_start__
ldr r1, =__ctors_start__
ldr r2, =__ctors_end__
bl memory_copy
ldr r0, =__dtors_load_start__
ldr r1, =__dtors_start__
ldr r2, =__dtors_end__
bl memory_copy
ldr r0, =__rodata_load_start__
ldr r1, =__rodata_start__
ldr r2, =__rodata_end__
bl memory_copy
ldr r0, =__tdata_load_start__
ldr r1, =__tdata_start__
ldr r2, =__tdata_end__
bl memory_copy
#ifdef INITIALIZE_SECONDARY_SECTIONS
ldr r0, =__data2_load_start__
ldr r1, =__data2_start__
ldr r2, =__data2_end__
bl memory_copy
ldr r0, =__text2_load_start__
ldr r1, =__text2_start__
ldr r2, =__text2_end__
bl memory_copy
ldr r0, =__rodata2_load_start__
ldr r1, =__rodata2_start__
ldr r2, =__rodata2_end__
bl memory_copy
#endif /* #ifdef INITIALIZE_SECONDARY_SECTIONS */
#ifdef INITIALIZE_TCM_SECTIONS
ldr r0, =__data_tcm_load_start__
ldr r1, =__data_tcm_start__
ldr r2, =__data_tcm_end__
bl memory_copy
ldr r0, =__text_tcm_load_start__
ldr r1, =__text_tcm_start__
ldr r2, =__text_tcm_end__
bl memory_copy
ldr r0, =__rodata_tcm_load_start__
ldr r1, =__rodata_tcm_start__
ldr r2, =__rodata_tcm_end__
bl memory_copy
#endif /* #ifdef INITIALIZE_TCM_SECTIONS */
/* Zero the bss. */
ldr r0, =__bss_start__
ldr r1, =__bss_end__
movs r2, #0
bl memory_set
ldr r0, =__tbss_start__
ldr r1, =__tbss_end__
movs r2, #0
bl memory_set
#ifdef INITIALIZE_SECONDARY_SECTIONS
ldr r0, =__bss2_start__
ldr r1, =__bss2_end__
mov r2, #0
bl memory_set
#endif /* #ifdef INITIALIZE_SECONDARY_SECTIONS */
#ifdef INITIALIZE_TCM_SECTIONS
ldr r0, =__bss_tcm_start__
ldr r1, =__bss_tcm_end__
mov r2, #0
bl memory_set
#endif /* #ifdef INITIALIZE_TCM_SECTIONS */
/* Initialize the heap */
ldr r0, = __heap_start__
ldr r1, = __heap_end__
subs r1, r1, r0
cmp r1, #8
blt 1f
movs r2, #0
str r2, [r0]
adds r0, r0, #4
str r1, [r0]
1:
#ifdef INITIALIZE_USER_SECTIONS
ldr r2, =InitializeUserMemorySections
blx r2
#endif
/* Call constructors */
ldr r0, =__ctors_start__
ldr r1, =__ctors_end__
ctor_loop:
cmp r0, r1
beq ctor_end
ldr r2, [r0]
adds r0, #4
push {r0-r1}
blx r2
pop {r0-r1}
b ctor_loop
ctor_end:
/* Setup initial call frame */
movs r0, #0
mov lr, r0
mov r12, sp
.type start, function
start:
/* Jump to application entry point */
#ifdef FULL_LIBRARY
movs r0, #ARGSSPACE
ldr r1, =args
ldr r2, =debug_getargs
blx r2
ldr r1, =args
#else
movs r0, #0
movs r1, #0
#endif
ldr r2, =APP_ENTRY_POINT
blx r2
.thumb_func
exit:
#ifdef FULL_LIBRARY
mov r5, r0 // save the exit parameter/return result
/* Call destructors */
ldr r0, =__dtors_start__
ldr r1, =__dtors_end__
dtor_loop:
cmp r0, r1
beq dtor_end
ldr r2, [r0]
add r0, #4
push {r0-r1}
blx r2
pop {r0-r1}
b dtor_loop
dtor_end:
/* Call atexit functions */
ldr r2, =_execute_at_exit_fns
blx r2
/* Call debug_exit with return result/exit parameter */
mov r0, r5
ldr r2, =debug_exit
blx r2
#endif
/* Returned from application entry point, loop forever. */
exit_loop:
b exit_loop
.thumb_func
memory_copy:
cmp r0, r1
beq 2f
subs r2, r2, r1
beq 2f
1:
ldrb r3, [r0]
adds r0, r0, #1
strb r3, [r1]
adds r1, r1, #1
subs r2, r2, #1
bne 1b
2:
bx lr
.thumb_func
memory_set:
cmp r0, r1
beq 1f
strb r2, [r0]
adds r0, r0, #1
b memory_set
1:
bx lr
// default C/C++ library helpers
.macro HELPER helper_name
.section .text.\helper_name, "ax", %progbits
.global \helper_name
.weak \helper_name
\helper_name:
.thumb_func
.endm
.macro JUMPTO name
#if defined(__thumb__) && !defined(__thumb2__)
mov r12, r0
ldr r0, =\name
push {r0}
mov r0, r12
pop {pc}
#else
b \name
#endif
.endm
HELPER __aeabi_read_tp
ldr r0, =__tbss_start__-8
bx lr
HELPER __heap_lock
bx lr
HELPER __heap_unlock
bx lr
HELPER __printf_lock
bx lr
HELPER __printf_unlock
bx lr
HELPER __scanf_lock
bx lr
HELPER __scanf_unlock
bx lr
HELPER __debug_io_lock
bx lr
HELPER __debug_io_unlock
bx lr
HELPER abort
b .
HELPER __assert
b .
HELPER __aeabi_assert
b .
HELPER __cxa_pure_virtual
b .
HELPER __cxa_guard_acquire
ldr r3, [r0]
#if defined(__thumb__) && !defined(__thumb2__)
movs r0, #1
tst r3, r0
#else
tst r3, #1
#endif
beq 1f
movs r0, #0
bx lr
1:
movs r0, #1
bx lr
HELPER __cxa_guard_release
movs r3, #1
str r3, [r0]
bx lr
HELPER __cxa_guard_abort
bx lr
HELPER __sync_synchronize
bx lr
HELPER __getchar
JUMPTO debug_getchar
HELPER __putchar
JUMPTO debug_putchar
HELPER __open
JUMPTO debug_fopen
HELPER __close
JUMPTO debug_fclose
HELPER __write
mov r3, r0
mov r0, r1
movs r1, #1
JUMPTO debug_fwrite
HELPER __read
mov r3, r0
mov r0, r1
movs r1, #1
JUMPTO debug_fread
HELPER __seek
push {r4, lr}
mov r4, r0
bl debug_fseek
cmp r0, #0
bne 1f
mov r0, r4
bl debug_ftell
pop {r4, pc}
1:
ldr r0, =-1
pop {r4, pc}
// char __user_locale_name_buffer[];
.section .bss.__user_locale_name_buffer, "aw", %nobits
.global __user_locale_name_buffer
.weak __user_locale_name_buffer
__user_locale_name_buffer:
.word 0x0
#ifdef FULL_LIBRARY
.bss
args:
.space ARGSSPACE
#endif
/* Setup attibutes of stack and heap sections so they don't take up room in the elf file */
.section .stack, "wa", %nobits
.section .stack_process, "wa", %nobits
.section .heap, "wa", %nobits