STM32链接文件和启动文件分析& J$ m6 D2 f, \$ g, p/ [% S
SOC: STM32F401CCU6 256K flash 64k ram6 P+ @$ k, P/ L9 [
Mem map:2 I* ^* [. G" r3 x3 m% M
7 e B) e/ l" v& I K, c
# K; p2 p5 S1 M# ?
' e2 [6 b9 n! }5 O1 A) C; }4 `* \链接文件部分:0 C5 h" @. E# h* Z& m) }
. = ALIGN(4);是指4字节对齐& S2 `0 E ^$ }& m+ ?) b
.,小数点表示当前的地址位置,例如__MALLOC_SYMBOLS = .;的意思是`__MALLOC_SYMBOLS 的地址就是.malloc段的地址
9 ^7 \: Y( `! r5 _9 J3 f- c' E一般的程序中包含常见的几个段:8 V P h1 Z2 u" f) P' j' y
text(存放程序), s1 O' K8 C/ |. I& w: d
rodata(存放被初始化的数据)8 w$ h0 x0 i+ u; A' X0 ]2 q
data(表示初始化不为0的变量)& p1 z* P! U6 q" D
bss(表示初始化值为默认的全局变量)4 M- {5 [ s+ [
text,rodata放在flash中,而data中的初始化值作为rodata放在flash中,变量在ram中占有空间,bss占ram空间! c3 O0 Q- S' i8 s9 g+ P( c
如果没有AT> FLASH,那么编译bin文件时地址是连续的* W- C1 b% q6 z. a/ h
- /*3 p- X1 U7 t- e6 l
- *****************************************************************************6 Z5 O- j9 ]5 h* n+ [7 J) U
- ** ]+ k; |: ?3 n0 ^, l3 O. c# A" ?
- 6 K4 V0 z0 p `' Y! T
- ** File : stm32_flash.ld
e7 J" ~" P" k: T9 g1 m7 K5 F( a - **2 C- y* u8 J. c0 u( F, ^- G J
- ** Abstract : Linker script for STM32F401VC Device with
( b- P+ v% J$ K2 M4 X/ Q - ** 256KByte FLASH, 64KByte RAM
6 P, m% [7 | N# @: g T; J# A - **, O9 p- |% I; m. Y
- ** Set heap size, stack size and stack location according
( c* p0 B/ n. a/ M9 {5 J! u) k - ** to application requirements., N" d; U+ h4 y$ s3 ^1 F _
- **
1 @0 a4 E. X4 B6 g8 o - ** Set memory bank area and size if external memory is used.
1 i! Q0 S Z$ l* t2 m: L h Q) @ - **
( y, r; ^# m8 o. c - ** Target : STMicroelectronics STM32
/ q+ g) S, J1 w& s7 B - **( ?) A% x) o1 P! g# T& [
- ** Environment : Atollic TrueSTUDIO(R)
; n& a1 d# v) t- G8 h - **
' x' \- k& S' ~. a" b+ u3 \: u$ @ w - ** Distribution: The file is distributed as is, without any warranty m) P- u, |# W0 b
- ** of any kind.
' x! a6 K* x! j - **
( n, B$ V/ K/ D1 Z - ** (c)Copyright Atollic AB.% y2 }6 i- K( ^
- ** You may use this file as-is or modify it according to the needs of your" f* T* ^9 D, @" A- D
- ** project. This file may only be built (assembled or compiled and linked)! a8 p2 r7 A5 W% P
- ** using the Atollic TrueSTUDIO(R) product. The use of this file together9 Q9 i6 N' t/ O6 C6 A, D5 i) [
- ** with other tools than Atollic TrueSTUDIO(R) is not permitted., a( L) N$ f( l# i: U: K
- **
! F# z: E K+ W- _ - *****************************************************************************
0 ?4 @. {7 R; ~+ D8 P - */8 E) ^; f) u: p3 I, s
- /* Entry Point */' S2 Y7 x' Q4 n# f, U0 j8 \# }: w d
- //指定入口地址为Reset_Handler
5 W" L$ L& h8 x - //ENTRY(SYMBOL) :将符号SYMBOL的值设置成入口地址。
5 I% f0 z$ R3 f% `6 W7 D0 W5 a - //入口地址(entry point)是指进程执行的第一条用户空间的指令在进程地址空间的地址
& Q, V+ |; Y! D, k/ ]' z - //ld有多种方法设置进程入口地址, 按一下顺序: (编号越前, 优先级越高)
& c" i* G$ N% K2 ` - //1, ld命令行的-e选项% Q: |* z7 s& u' Z8 ?
- //2, 连接脚本的ENTRY(SYMBOL)命令
9 l+ `, B# Y L: j+ }! v1 g - //3, 如果定义了start符号, 使用start符号值4 \6 C6 J( i2 o! h. x- v
- //4, 如果存在.text section, 使用.text section的第一字节的位置值
; j$ N: @+ k1 `; b) X& F) ?$ l - //5, 使用值0
0 A2 G4 ~, q$ R( s - ENTRY(Reset_Handler)
[# |6 Z* x( K$ L; ~2 J6 T) {( K - " {: {" k( r1 b5 h; n
- /* Highest address of the user mode stack */2 u% B; F H- t6 I3 J8 ]
- //ram的结束地址
/ _3 t( g) M. F3 F# E, w! x% ~ - _estack = 0x20010000; /* end of RAM */
" \* A4 H* p, S; H9 ~, y# O - /* Generate a link error if heap and stack don't fit into RAM */
4 m# e v' q$ [; `1 I8 s; J/ {) V: G - //指定的最小的堆栈大小
, X, B0 g/ k+ V I+ ]8 n& E5 o; T - _Min_Heap_Size = 0x200; /* required amount of heap */
' ?' s o5 ~5 `& h; C; M - _Min_Stack_Size = 0x400; /* required amount of stack */
5 p* [7 W" i8 H% e! y( x
+ a7 K' _% f0 j j" g9 H2 w0 Z+ E) b- /* Specify the memory areas */
( @) p9 N5 D: r$ c - //指定flash和sram大小$ D# @# L% S1 q3 G( Q
- MEMORY: W, P" Q" h) B
- {+ w) I% E& W0 T& p- }/ [' u
- FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 256K/ M7 a0 u8 F- P
- RAM (xrw) : ORIGIN = 0x20000000, LENGTH = 64K, J& n) Z* e: s5 Y: T
- }7 r+ m8 k" P. G# H% @' \
" F0 L' k) J# Z6 {- /* Define output sections */
: H0 ]( _8 a' y# i" `7 y6 K* k - // 输出文件组合布局9 r4 x3 G5 Y" _. w, P: c: w+ x
- SECTIONS6 j" H/ D s }/ [; l& J
- {
9 m, w2 X- b& {) `0 ]9 Z9 C+ U+ U - /* The startup code goes first into FLASH */
! m- H/ U. u$ [ - //将向量表放在最前面,上电即可执行2 ~, O0 f3 M7 |7 a8 \6 q1 I0 K
- .isr_vector :
: M, V# o) G! m7 b0 x% d$ j - {
e. r; j; k/ d7 t2 U' T - . = ALIGN(4);. C, E7 `: B8 `3 @
- KEEP(*(.isr_vector)) /* Startup code */) H E( D1 c" _8 U/ z8 R
- . = ALIGN(4);3 t% }3 Y; {' v/ { Y6 Q( o2 ?5 E/ P& y% Q
- } >FLASH
* ~4 y3 Q7 {. S; A0 `' q1 [9 ^ m* U - . r! E) W R: Y' w1 i! ~# ]
- /* The program code and other data goes into FLASH */
- J& s v4 l& {. f0 ] - //指定text段,主要存放代码+ y- C K) f% N) J. v
- .text :
: V* S7 ~' m! F' o1 f8 r - {
/ N5 z$ |2 u! {" B9 a9 ~. E - . = ALIGN(4);( d2 w5 K* S6 i- F' {
- *(.text) /* .text sections (code) */2 J" i& k# J2 g8 ~( I0 l
- *(.text*) /* .text* sections (code) */% k$ b' o; b0 v) [" C
- *(.glue_7) /* glue arm to thumb code */
j0 C' x) k% c# t/ X/ l3 x - *(.glue_7t) /* glue thumb to arm code */
4 w* Z- ?* s# `4 f& z8 G$ s' g% K - *(.eh_frame)2 e M( U: P) i2 r: {
) f/ p9 U4 \+ b+ V& [7 `; Z- KEEP (*(.init))
( @/ x. `4 ]8 U [! A - KEEP (*(.fini))0 i" c z/ \' A; }& H
1 w/ w1 H; S/ w4 V( e- C1 f/ L0 D/ v- . = ALIGN(4);
$ U+ v" K4 l5 n4 u6 g Q" p2 U - _etext = .; /* define a global symbols at end of code */1 n3 d7 e% b9 M9 ]+ o+ G& \, |; L
- } >FLASH
' O8 R ]7 j1 z1 `5 @
h9 k! ^/ O2 `: m7 ?! d, i; L- /* Constant data goes into FLASH */7 \# D3 {+ ~* ]+ z
- //指定只读段
; |/ _8 J, }2 W: A - .rodata :. ?9 _- O8 o2 l- M) o5 [# H x
- {
* y1 F/ U$ F0 X6 s( z - . = ALIGN(4);: s9 I D9 V, k2 i' e4 z
- *(.rodata) /* .rodata sections (constants, strings, etc.) */& T y" {* V$ _' U
- *(.rodata*) /* .rodata* sections (constants, strings, etc.) */+ Z i9 S/ E5 n$ C4 _" M3 o! _
- . = ALIGN(4);9 ?" s% C) ~- J3 J; x8 }% b
- } >FLASH, s) y7 @/ _ f
- ( L, X( }& w) r3 F" p! S
- .ARM.extab : { *(.ARM.extab* .gnu.linkonce.armextab.*) } >FLASH
7 n4 g0 P, |1 o7 v - .ARM : {
, s4 b+ M# I" m - __exidx_start = .;. L5 g9 k; f! T3 ]' X0 v! m/ S
- *(.ARM.exidx*)9 } ^7 w/ X' A3 q; N8 V* b
- __exidx_end = .;$ j$ J9 p' Q3 Z; D/ l
- } >FLASH& H. O- v2 e8 M( ^* w7 ], ^
- & U8 w# s# ]; [6 {5 U5 K9 f1 W. J
- .preinit_array :
, {) ^ f+ P4 G0 u; C: c) h! h0 o' c6 u - {
- f- {+ }" x2 h' j - PROVIDE_HIDDEN (__preinit_array_start = .);9 _. d3 o$ v U; u5 C; @
- KEEP (*(.preinit_array*))3 G! F8 e- b- }+ k. S/ ?$ f6 h/ B
- PROVIDE_HIDDEN (__preinit_array_end = .); A' z+ ]5 k. b0 R3 u: Z
- } >FLASH
6 {% D* I1 Z3 X R0 c* z - .init_array :
6 U* S" s2 z- e5 S - {
* f* r3 X6 b9 h - PROVIDE_HIDDEN (__init_array_start = .);
# f8 d- o8 U, [* \ - KEEP (*(SORT(.init_array.*)))2 x, V# r; C: p) i: Y. B# U6 O
- KEEP (*(.init_array*))
/ J) F4 @& @! Z0 o - PROVIDE_HIDDEN (__init_array_end = .);5 m5 c4 k; y& |% s, d
- } >FLASH
2 m9 N9 }2 r( J, _& e7 I - .fini_array :
; U$ ?) c# S. ~0 e* G# ^ - {* j& ~7 E6 [+ f8 n
- PROVIDE_HIDDEN (__fini_array_start = .);9 U% R2 x2 _, b3 ?+ Z
- KEEP (*(SORT(.fini_array.*)))
$ ?0 C) M! U" M9 z; B& f - KEEP (*(.fini_array*))
# g. @- P0 D% r/ _1 ?4 w5 I. e - PROVIDE_HIDDEN (__fini_array_end = .);
) V6 Z% e+ a1 q$ y - } >FLASH+ W" r2 {* C l! y
- / T) g# D6 S% N* b
- /* used by the startup to initialize data */
/ T* M+ q# d' f! n - //_sidata 保存.data的地址相当于_sidata = & .data
$ P* e3 n. n4 k5 F, E9 H F, Z4 r7 L - _sidata = LOADADDR(.data);
" ?- m) F1 j5 m+ d3 g: b
, ~$ d. `/ L8 ]0 Y9 K1 s1 X- /* Initialized data sections goes into RAM, load LMA copy after code */( S& ?; a2 b" H! o7 _
- //指定数据段在ram中,但是数据保存在flash中,在启动的时候需要将数据拷贝到ram中去。
. K1 c7 F9 c2 ^" G, { - .data : " f, |* ~- F( l5 P' X- G4 n2 ]8 O
- {
% l: m' U# o( q( r/ ^5 r# i& ] - . = ALIGN(4);: o4 x9 N x/ L' S# u+ o# J
- _sdata = .; /* create a global symbol at data start */: z( u: w" i0 R: ^
- *(.data) /* .data sections */
+ c6 ~& J0 b% W9 a - *(.data*) /* .data* sections */
: b2 `* z8 s+ `, i) ~- f5 I
' S$ v2 s/ Y& l# r% f- . = ALIGN(4);" D. a3 y0 x( x/ U
- _edata = .; /* define a global symbol at data end */9 e* F; k8 [, M1 p5 v
- } >RAM AT> FLASH
" O: ?9 n7 a# Z5 R4 ^! v2 M; B - 1 d* I* S& N. m# l. g7 c+ p: J7 k' r
- - _! z, t _' M) e( o n2 @
- /* Uninitialized data section */
3 A7 Y: M( T3 d- q. c9 G1 f/ T - //指定bss段
6 |& Z5 ^/ h1 C% Q' E - . = ALIGN(4);
' C# |, v) r& ]+ x6 }; f5 P! N - .bss :
/ R# q: d9 T4 Q; \ - {
9 r/ Y0 f. _8 H% X - /* This is used by the startup in order to initialize the .bss secion */( ^2 e: A, \. W) X5 g
- _sbss = .; /* define a global symbol at bss start */* K# f, X* B. p3 N, M
- __bss_start__ = _sbss;
3 G6 V ^0 \, O - *(.bss)
: q8 l* m2 a/ Q4 t0 }+ g - *(.bss*)4 ?/ z5 o8 G; ^9 u0 h
- *(COMMON)4 o* M& n$ }! d% l/ T% U
( T. r u; W7 H, c8 r- . = ALIGN(4);' A( W8 ^1 _( F* }( K9 }/ l
- _ebss = .; /* define a global symbol at bss end */3 y" X* |, _5 e7 {! k. d, h/ [; \
- __bss_end__ = _ebss;$ C+ q/ t0 l7 b
- } >RAM
( A+ q! U/ E, ^$ m - : |3 w7 y- D! G [+ X! W3 k$ D
- /* User_heap_stack section, used to check that there is enough RAM left */
5 G& i8 }7 n- _3 c" Z - //指定堆栈段4 z1 c* ?4 |4 l1 v
- ._user_heap_stack :
' f9 w8 o' q) S4 D - {
1 l7 w1 @$ [8 [ - . = ALIGN(4);
, b; c( I" r f# f0 O6 D+ D - PROVIDE ( end = . );
/ y" k; _% L) n/ X - PROVIDE ( _end = . );
; ]4 O2 M6 D! V8 \2 N3 R# Q: { - . = . + _Min_Heap_Size;
# S3 y5 m; q9 W6 Y# L - . = . + _Min_Stack_Size; q# P' |- ^5 _5 E3 f& f1 R! H% {
- . = ALIGN(4);" k: C9 S4 i9 o" e' c# m
- } >RAM1 T, ? ?. |# A* p2 w
- 3 j' [/ q3 Y* d
- /* Remove information from the standard libraries */
+ H9 C' N0 c A0 p# E; H _ - /DISCARD/ :
- y' F) U- f. P2 A, L - {* {$ o/ ?8 s5 n+ D( j
- libc.a ( * )) {' z. s* u4 L8 V/ g4 W
- libm.a ( * )
5 l1 D8 D/ z; ~. m - libgcc.a ( * )& g& F5 W$ Y8 I) L( }
- }# G# S9 k z2 b) V' s
- .ARM.attributes 0 : { *(.ARM.attributes) }. x" x6 ?- I, [7 C0 H; `3 Z( _
- }- R* \& l+ P9 f" j) \
复制代码
! s! t$ W9 d, V ?# G启动文件
, Y$ s4 I7 O* U/ Z" K% W; g- X- /**
6 V, F0 p* ~9 m9 t7 l+ x8 J - ******************************************************************************( G, T; d5 A+ \, X5 K9 j
- * @file startup_stm32f401xx.s
- l: }! Y: m5 q { - * @author MCD Application Team
3 ~+ V) }3 @! ]9 f - * @version V1.8.03 [7 I7 [5 s- |4 E0 b, p) Z
- * @date 09-November-2016: Z( X3 V3 Q* y, A7 r
- * @brief STM32F401xx Devices vector table for Atollic TrueSTUDIO toolchain.
- x3 \/ V# z5 P3 `0 l - * This module performs:/ l( A( z" C! G+ {
- * - Set the initial SP$ M0 d" C, Y: o+ {( h
- * - Set the initial PC == Reset_Handler,# Z" Q: r" a# U, Z) B% L: g% n
- * - Set the vector table entries with the exceptions ISR address
6 `/ X' o" \- X; i6 V - * - Configure the clock system
7 Y! o! N/ E0 p: g - * - Branches to main in the C library (which eventually
# x8 w3 z: }2 ?# e4 X - * calls main()).; G+ H& D: b9 ^0 |& v5 S# {, I6 K
- * After Reset the Cortex-M4 processor is in Thread mode,
! B" h$ w* H+ ~ - * priority is Privileged, and the Stack is set to Main.* `- U. v* R+ P
- ******************************************************************************+ l6 p6 d# t1 _: t! p2 ~& |
- * @attention9 H+ r. [. n- A$ D& ?, o( z: q
- *
9 |$ R8 q2 Z% Y% ?. q! k - * <h2><center>© COPYRIGHT 2016 STMicroelectronics</center></h2>
8 W R8 `& |$ l) l b% Z. M - *
, F" s( u* l6 E$ e - * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");- W+ t7 l+ _4 e0 [
- * You may not use this file except in compliance with the License.) R! g6 @" P& j8 c
- * You may obtain a copy of the License at:& A. {2 A9 t( t2 s
- *$ R7 g9 L+ \8 x7 f/ _
- * http://www.st.com/software_license_agreement_liberty_v2
. L* ]2 [5 v5 `4 t7 V+ [ - *
2 i: i. J- k, J - * Unless required by applicable law or agreed to in writing, software
5 B, a' S9 j1 e - * distributed under the License is distributed on an "AS IS" BASIS, - n1 _; E& E8 U. H; W
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
, J' L! a/ [- b6 {* T - * See the License for the specific language governing permissions and
; s) b9 `; V, ~2 X1 ^ - * limitations under the License.
: U3 Z5 G7 N# v - *! r* t" d) y$ T% q& X3 n) s/ X
- ******************************************************************************
9 q! Q, n# Y4 S% a9 c2 F; r7 R& y! w - */
8 G4 a+ ~ h' \& f7 J, _5 c -
2 F! y4 V( [- V" t) X4 Y0 H! B - .syntax unified //统一汇编语法-UAL
6 x X3 ?3 r H - .cpu cortex-m4 //CPU类型
2 D/ B' ]' ?$ i& T2 R - .fpu softvfp //fpu 类型& P. c$ ]3 d& v- v5 R7 ~1 t) @
- .thumb //thumb指令
/ K5 p% u% s; a8 [4 J, _ - ) D% u! q* d* J2 l9 g
- .global g_pfnVectors //全局变量,外部可见
$ y( Q. J q% {/ y, L. V6 Q - .global Default_Handler //全局变量# v" R# z5 l! D# O2 ?0 k; T
, _" A2 \0 q" v- /* start address for the initialization values of the .data section. 4 {0 M2 g7 l7 X
- defined in linker script */
9 D" N ?/ z: Y3 h4 Z* H - .word _sidata //保存.data地址的变量6 n% M. h7 R7 o$ y. i; F6 j
- /* start address for the .data section. defined in linker script */ , h+ |0 x$ `) p) k/ n) k. k( I
- .word _sdata //data 段的起始地址,_sidata 4字节对齐后的地址,在链接脚本中定义" i. J, w3 E: M" t
- /* end address for the .data section. defined in linker script */9 M9 W/ T) k8 S
- .word _edata //data段的结束地址
- y2 \7 j: J( K- p/ @ - /* start address for the .bss section. defined in linker script */
4 V8 ]) O' ~+ p! y - .word _sbss //bss的起始地址
, H. [$ o/ N# D0 t, | - /* end address for the .bss section. defined in linker script */; J7 r W# {7 k- L; E# X
- .word _ebss //bss的结束地址
4 h# K$ o! Z" r/ i1 G! G3 f+ U - /* stack used for SystemInit_ExtMemCtl; always internal RAM used */- k J- A+ ^$ J8 T& Q( ~
- ' U3 d+ v, Z% J. _0 m+ w
- /**4 j+ X/ z% ] r$ m5 I4 U/ v1 }
- * @brief This is the code that gets called when the processor first
* G0 @- ]$ @& J9 m- }0 d8 J2 t( X - * starts execution following a reset event. Only the absolutely
% ~( B! h' d) b8 Q$ x- E4 m - * necessary set is performed, after which the application
- N1 O d R" |1 z- |, R - * supplied main() routine is called. 5 `4 G6 g; j7 U( u( o
- * @param None
+ h0 o: k1 ?, M( {. V/ b - * @retval : None
5 a* ~' w8 V" M3 R - */: W- V6 H$ q1 Y2 _- _5 b, `: W
8 }) s, J/ o$ ]+ A7 M5 r! w* A6 Z& s- .section .text.Reset_Handler //设置新的代码段3 e) k* W. Q3 a- ~* U8 L
- .weak Reset_Handler //.weak 声明其他的同名标号优先于该标号被引用。9 J; S; j- s: E$ q# ~5 O
- .type Reset_Handler, %function //.type将Reset_Handler 指定为函数
( L. D4 l5 K( E& a* e - Reset_Handler: ! O: G, x! L( _- Y/ P$ {
8 R( w1 U0 c7 H4 M- /* Copy the data segment initializers from flash to SRAM */ 4 L$ B* R# g1 a
- movs r1, #0 //将立即数0存放到r16 p) I0 I& ?" D. V' U
- b LoopCopyDataInit //跳转到LoopCopyDataInit 执行
$ x, M* q( [' p$ X - //下面是将初始化的data数据拷贝到sram中去( o+ n1 o$ M/ r( A
- CopyDataInit:
+ A0 k% C$ j2 \$ o# b/ { _ - ldr r3, =_sidata //r3 = _sidata (flash中存放data的地址)$ q7 ^$ n/ \9 Y! k0 R2 v/ _) }
- ldr r3, [r3, r1] //r3 = *(r3+r1) 取出该位置的数据/ @( d/ ?; ~% z3 H
- str r3, [r0, r1] //*(r0 + r1) = r3 将数据写入sram中r0 + r1的地方$ T9 c4 [1 l" G
- adds r1, r1, #4 //r1 += 4+ k2 s& e; O- Q7 Z. R3 o
-
/ {; |2 r; @* }. D6 T5 w - LoopCopyDataInit:1 d; ?' t( r- w: ]) |1 x6 E
- ldr r0, =_sdata //r0 = _sdata ld文件中定义
; O* J" T0 G: a. j) D9 ? - ldr r3, =_edata //r3 = _edata ld文件中定义2 U* a6 H+ b1 |! ~9 f
- adds r2, r0, r1 //r2 = r0+r1
: o" c: m, w \$ @" F- ^ - cmp r2, r3 //比较r2和r3更新标志位
. W3 b* L* k8 ?2 f( d3 D - bcc CopyDataInit //C is clear 就跳转(无符号数小r2 < r3)因为汇编是顺序执行,所以这里会被循环执行,直到r2 == r3- z2 g: [# b' O/ W& l. D0 m
- ldr r2, =_sbss //r2 = _sbss ld文件中定义) Z! I/ |" ^- ]( r2 N1 s
- b LoopFillZerobss
9 J3 `9 A C, h8 R M9 c - /* Zero fill the bss segment. */
* C/ f& \8 ^0 h& c# X - FillZerobss:$ V& D8 ?1 g& p! b4 E! t) D6 E, O
- movs r3, #0 //r3 = 0/ r" j. I% t. p: c8 k) w: Z/ g
- str r3, [r2], #4 //*r2 = 0; r2 += 4;$ M# y. ^" s. @, V
- 6 b1 V# F% b& y
- LoopFillZerobss: //将bss数据初始化为0! m9 W- \; G5 D" K& a
- ldr r3, = _ebss //r3 = _ebss ld文件中定义* g9 m# P1 M$ m$ s! x3 D7 X- N7 g1 E
- cmp r2, r3 //比较r2 r3& Y+ s; u! ~, k9 y3 X7 z
- bcc FillZerobss //r2 < r3跳转
C! ]0 r% v" ~( C1 T( m; n
2 U& ?9 K) k/ j/ P& N- /* Call the clock system intitialization function.*/
5 h5 A6 q' Z( P- L& B- N: w - bl SystemInit //跳转到SystemInit
3 B" N- z' I4 f" @* E4 V& A0 F8 w0 S - /* Call static constructors */
% @, j0 v+ w2 U; P0 o - //__libc_init_array 这个函数中执行的关键过程如下:
4 L w$ e; v X* G E - //调用 .preinit_array 段中的预初始化函数# s+ O) q; D5 B, F
- //调用 .init 段中的 _init 函数0 X+ \$ q3 P' H7 d% s* ?$ ~ k8 ?
- //调用 .init_array 中的所有函数7 O5 d" e' Y( z3 U! _0 G
- bl __libc_init_array
- M; Q0 L+ f! G0 M0 ~ - /* Call the application's entry point.*/
7 Z7 U' u& G) Q7 |2 n" U8 G - bl main
+ p6 [7 R. x9 s5 n2 u6 q" `0 I - bx lr 4 f. `( z7 p0 v
- // .size name,expression:将符号name所占空间设为expression(就是Reset_Handler函数大小) ' z; G2 A9 J) L x$ Y
- .size Reset_Handler, .-Reset_Handler8 h% @" g- P/ ]
0 I4 R8 a7 c; r) f7 s" P3 J- /**& p2 f5 ~7 e+ y! C" t& u
- * @brief This is the code that gets called when the processor receives an
$ F/ `1 F+ ]) `3 Y1 X& W9 ] - * unexpected interrupt. This simply enters an infinite loop, preserving
7 A$ w3 d( H' K* v& x, k5 M - * the system state for examination by a debugger.6 n# ?) @2 Q1 i
- * @param None
+ t4 V- G7 t# V* Q' a3 L/ p - * @retval None " N2 }- e! {) O; s( o* g
- */
. j+ h/ s7 s0 s! l* f - //Default_Handler是个死循环* m% D* a; U8 t* M' P
- .section .text.Default_Handler,"ax",%progbits
2 a! C9 p s% g; S; a# Q8 I - Default_Handler:& u, h" o H/ ]+ a8 l
- Infinite_Loop:& v% {9 `% F+ H: I% t
- b Infinite_Loop
/ w* z( f% a! L& u/ j' D. O) a# m - .size Default_Handler, .-Default_Handler
0 Y% R0 }% T! R9 Y7 H) j' P* K - /******************************************************************************
9 U9 {8 m+ O2 N# y3 d - *
7 Q( P* Y9 L. v: _ - * The minimal vector table for a Cortex M3. Note that the proper constructs& X3 t- z9 d% H; c0 M: ?1 W- S
- * must be placed on this to ensure that it ends up at physical address
8 r& K* f5 C: ]% ]0 ?2 V \ - * 0x0000.0000.' y- R7 p4 I I# \) d
- *
; m5 e& u( P& r% r, }9 M. S - *******************************************************************************/, M2 [. l/ g# G/ J
- .section .isr_vector,"a",%progbits, u" N1 z1 R/ X2 I$ h/ l5 C; Y% I( s
- .type g_pfnVectors, %object% s7 j ]9 X; ]+ Q) y; W
- .size g_pfnVectors, .-g_pfnVectors* t, n! n, s _0 R" u
- $ j- a7 l: b0 u+ U" q' O' c2 P
- // _estack是栈顶的值,这个值保存在flash的0地址处,flash的地址为0x08000000,4 a/ j! P; e. Z4 V( G/ z& B: t, X9 l
- // 所以0x08000000保存_estack的值
9 H% K& Q" S1 r0 P4 O) X' H - g_pfnVectors:! z4 Q) }& ^6 q2 c1 j. O0 b% B$ V4 ^
- .word _estack/ h- z4 f8 P$ G9 R! R4 m
- .word Reset_Handler
4 _" n/ t# o8 e* {0 s - .word NMI_Handler
5 V5 E, q" K8 r* J, ^5 _ - .word HardFault_Handler' S# |! f B. c; c3 ^
- .word MemManage_Handler9 a" C/ q. u4 L# h
- .word BusFault_Handler; c) {2 Q3 ?2 K* l2 T; N
- .word UsageFault_Handler" N# ~7 ~8 Z$ x" w' t0 X
- .word 0
5 ^/ H, w+ O. j - .word 0! v' u& y( j. o- ]4 m
- .word 0
/ T7 E d6 P" N0 Y' ~1 Q - .word 0
9 {% v; _! \. M0 ?9 R/ @/ h - .word SVC_Handler" K8 D/ q$ h4 C) x: [) h+ e8 P
- .word DebugMon_Handler% ]9 K7 L: g( l# ~* @
- .word 06 r M4 ?6 v& B4 F1 p9 p
- .word PendSV_Handler
$ J, r$ g* k) A4 o& {1 a: E& F" L - .word SysTick_Handler; o3 E7 q' z2 ~7 o/ c7 f
- 5 c5 g- a8 \3 P
- /* External Interrupts */8 I" v5 z3 U* ~0 P7 z' |; p
- .word WWDG_IRQHandler /* Window WatchDog */ 4 D$ s n8 p8 L5 X; Y, B j
- .word PVD_IRQHandler /* PVD through EXTI Line detection */ 2 L+ S8 p5 i1 z/ g2 H- s! k
- .word TAMP_STAMP_IRQHandler /* Tamper and TimeStamps through the EXTI line */ 6 a; R7 g6 C$ b
- .word RTC_WKUP_IRQHandler /* RTC Wakeup through the EXTI line */
8 W/ L! `& i9 `% S - .word FLASH_IRQHandler /* FLASH */
' G9 w1 u$ V, z% L - .word RCC_IRQHandler /* RCC */
6 o" m, C0 S( I' A - .word EXTI0_IRQHandler /* EXTI Line0 */
/ m# G6 `, h/ T" ~ - .word EXTI1_IRQHandler /* EXTI Line1 */
. {6 E# A- `1 J1 R5 ]3 w - .word EXTI2_IRQHandler /* EXTI Line2 */ % R1 l* t' f8 @2 j8 v6 C
- .word EXTI3_IRQHandler /* EXTI Line3 */
4 }, o- n, }/ A9 z7 t - .word EXTI4_IRQHandler /* EXTI Line4 */ $ i5 R+ o: f' L6 d! _
- //略...$ L- R, F; ]. ^; Y
- * u/ m/ W; v# g
- /*******************************************************************************
0 ^4 s7 U) Q5 X: t4 L9 D- ]$ n - *; h2 D" _7 ?& \" @/ F- x2 w# D/ }
- * Provide weak aliases for each Exception handler to the Default_Handler.
: `: C) M7 Y" x' @ - * As they are weak aliases, any function with the same name will override 9 n) ` d/ G1 F! s
- * this definition.- k% @5 N, ^' K6 C: p
- * 6 F! F6 t! D! L9 ~' K0 a
- *******************************************************************************/
. v& |( f4 Y8 N - .weak NMI_Handler
, h7 J5 h$ [8 Q" P( p8 C - .thumb_set NMI_Handler,Default_Handler" R- r& t2 [8 P4 ]8 a) J
- 2 }& Z# w {$ I+ s- [, z
- .weak HardFault_Handler
! o2 o9 K8 C( s$ d# ?$ \: T - .thumb_set HardFault_Handler,Default_Handler- j5 ~# U$ {( p; V& O, L; K
- ) N; Q% N" c4 u9 D& \
- .weak MemManage_Handler& [) P9 k" U: M. {$ i
- .thumb_set MemManage_Handler,Default_Handler& b+ c2 X& N; Q" H/ D& \) g% L
-
' ^8 F2 Y9 g1 B1 ` - .weak BusFault_Handler2 l5 B" t' o" a' m% Z1 V
- .thumb_set BusFault_Handler,Default_Handler: L1 P+ v7 T- `- n9 g
/ a; y, p& N! p' ] s- }# D1 D+ \- .weak UsageFault_Handler2 G+ n* r' r8 l: a
- .thumb_set UsageFault_Handler,Default_Handler
9 I% y6 t4 L3 B6 b. t' w2 W$ P3 y1 {
+ ^% ?0 F: O+ r" X- .weak SVC_Handler
* [. S4 d: S7 E, D4 q3 w - .thumb_set SVC_Handler,Default_Handler. d$ E3 z+ J4 ]8 b
% K- k+ y) N% d" }- .weak DebugMon_Handler
, P5 ]4 g3 k* O9 K6 p" A. U n( n - .thumb_set DebugMon_Handler,Default_Handler
. V3 b" t, n9 N0 F: E! l( q) ]+ n
4 p8 Y" r$ M/ L2 g$ j- .weak PendSV_Handler: n. y3 Q; }) _: s O R
- .thumb_set PendSV_Handler,Default_Handler
4 [! n$ T9 o! {# v' B w, o: N/ i& u | - . V6 S' S4 V* Z5 z- n$ R. o# y
- .weak SysTick_Handler3 i& L0 M/ ~4 B& E g" c
- .thumb_set SysTick_Handler,Default_Handler
( r# @/ c2 Q1 { - ) X4 ^' \/ ]: X/ `8 x$ v) J9 t$ Q
- .weak WWDG_IRQHandler 8 \' _' ?8 o6 r9 s
- .thumb_set WWDG_IRQHandler,Default_Handler % h8 s0 F: o1 o1 j
- ( V+ z; P9 A5 D2 T* ~( e! l
- .weak PVD_IRQHandler 2 y& B/ G% E% E% R" F9 P& S
- .thumb_set PVD_IRQHandler,Default_Handler
) f# h( O3 o7 p0 e% G9 X -
1 I# b/ K0 P8 O3 ]6 C" ` - .weak TAMP_STAMP_IRQHandler
- k3 s- g" z# [/ f# ?" | - .thumb_set TAMP_STAMP_IRQHandler,Default_Handler
0 ?5 r& k! V6 d) f. b- o1 H$ n -
/ b6 l3 C3 o1 i8 G0 r3 \ - //略...% N3 E& n9 S; l. U, N7 ?4 v
-
( N0 M& u/ p0 M- F2 W - /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
l+ G: G% g: j; U5 ~; O - / N' f" Z* q) M+ D. \& Y' v
复制代码
7 Y9 D# p$ V) Z, e( W总结:stm32链接文件链接后布局如下,可以看到跟链接文件的配置是一致的,Flash的起始地址放的是.isr_vector,isr_vector的第一个地址放的是_estack,也就是msp(栈顶指针的值)
& }( P) M$ v4 ~7 O8 X' }4 D# g F
6 p2 b- b& ]0 A" Y( R/ |- tony@DESKTOP-VP4O54O:~/workdir/tony_linux_stm32_cmake/build$ readelf -S USER.elf ! i7 C& r2 [/ }! s
- There are 23 section headers, starting at offset 0x95690:
/ K3 ^. `, ~6 L" @* K9 p% h& k
! Z6 V- g# O( O, ]" a5 N; o- Section Headers:. |# _- u0 l3 Q/ Y
- [Nr] Name Type Addr Off Size ES Flg Lk Inf Al
8 k; v$ R% x$ l+ U9 V - [ 0] NULL 00000000 000000 000000 00 0 0 0: D1 L2 b- u6 K8 f+ P% U5 G
- [ 1] .isr_vector PROGBITS 08000000 010000 000194 00 A 0 0 1
6 H) q2 ^" ^1 k - [ 2] .text PROGBITS 08000194 010194 000afc 00 AX 0 0 4
+ Y e5 o G; F - [ 3] .rodata PROGBITS 08000c90 020010 000000 00 WA 0 0 1+ A" s. n4 \ a: D% [) C4 E3 S
- [ 4] .init_array INIT_ARRAY 08000c90 010c90 000004 04 WA 0 0 4
6 b* \* L" _: [+ S& @0 m2 i" C. A - [ 5] .fini_array FINI_ARRAY 08000c94 010c94 000004 04 WA 0 0 44 d y+ X6 P* G! V3 p+ w! }
- [ 6] .data PROGBITS 20000000 020000 000010 00 WA 0 0 4' b% R! ]4 N7 V/ \
- [ 7] .bss NOBITS 20000010 020010 0000e8 00 WA 0 0 4
3 N1 `% |7 T3 C- c5 A* Y - [ 8] ._user_heap_stack NOBITS 200000f8 0200f8 000600 00 WA 0 0 1% o) G- ^, ]* f, R1 V3 w
- [ 9] .ARM.attributes ARM_ATTRIBUTES 00000000 020010 000030 00 0 0 1
) @3 a9 v& L/ H - [10] .debug_line PROGBITS 00000000 020040 003936 00 0 0 1/ w2 m# Q% b& o8 K9 S% ]
- [11] .debug_info PROGBITS 00000000 023976 003df2 00 0 0 1
6 |5 O5 ], N* j" }; n) A - [12] .debug_abbrev PROGBITS 00000000 027768 000ace 00 0 0 1' J8 D7 K& `& T8 \
- [13] .debug_aranges PROGBITS 00000000 028238 000470 00 0 0 8
- F2 R( q, n3 d3 w" S - [14] .debug_str PROGBITS 00000000 0286a8 064708 01 MS 0 0 1
3 S' I* b. ~4 V8 K! a+ ^ - [15] .debug_ranges PROGBITS 00000000 08cdb0 0003f8 00 0 0 8, n3 B C" J' k/ W/ f1 N0 k' H
- [16] .debug_loc PROGBITS 00000000 08d1a8 0027c4 00 0 0 1$ o0 r+ m) K" G* _2 \; l# \
- [17] .debug_macro PROGBITS 00000000 08f96c 00345e 00 0 0 1
8 y% ?' N4 R8 E- s+ ^; D8 W - [18] .comment PROGBITS 00000000 092dca 000049 01 MS 0 0 1( m2 F7 p; B4 b9 F# h% X! G* A3 k
- [19] .debug_frame PROGBITS 00000000 092e14 00121c 00 0 0 4
* v$ j* o" F3 _5 ]# s9 V6 [ - [20] .symtab SYMTAB 00000000 094030 000d00 10 21 105 4: g- l. g: Q) W" O: w1 L7 m6 @
- [21] .strtab STRTAB 00000000 094d30 000869 00 0 0 1+ U/ p5 O) w' J
- [22] .shstrtab STRTAB 00000000 095599 0000f6 00 0 0 1
( O/ w7 j5 \% S+ [ - Key to Flags:
" j- o& u: B" y$ H - W (write), A (alloc), X (execute), M (merge), S (strings), I (info),! ^) N. Y. v6 z+ J
- L (link order), O (extra OS processing required), G (group), T (TLS),
. i o `; M& p4 B( R - C (compressed), x (unknown), o (OS specific), E (exclude),
" ^' d3 v5 a! Q, G7 o - y (purecode), p (processor specific)2 N5 l: j2 p, F" t& H: a
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* P. V2 k6 V9 H; @1 w/ ]3 j所以上电后会从08000000 执行,对应的异常处理函数是Reset_Handler,Reset_Handler函数做的工作首先将flash中存放的初始化的data数据拷贝到sram中(0x20000000),然后将Bss段中的数据全部初始化为0,调用SystemInit 函数初始化时钟,最后跳转到Main函数执行。& r4 S H Z" D" V/ C. J' o
startup.s中开头注释也有总结:
) R/ Z0 y, f9 P3 c- Set the initial SP
2 Y/ V3 G, V+ g1 [- Set the initial PC == Reset_Handler,
, @# a* Q0 g6 N3 D- Set the vector table entries with the exceptions ISR address% ^6 K& j: H9 m2 w8 O0 b
- Configure the clock system- C8 G- S ~. j
- Branches to main in the C library (which eventually calls main()).3 Q) ^9 G ~5 ~3 p
1.初始化堆栈寄存器,这里msp寄存器时机器上电后就由硬件将flash 08000000 中存的栈顶的值load到msp) b. F# {3 S9 `8 v. X
寄存器中。& G9 p' x0 S2 a; l9 b6 {' E
2.调用08000004 Reset_Handler异常处理函数
6 ~! }! g* P2 \# R3.设置异常向量表
* x1 ~6 c' n" W, m7 n4.配置系统时钟,SystemInit8 f3 {# o# u2 Q4 M4 B9 H
5.调用Main7 j5 Z* E' x' Q+ {, E
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9 d/ {6 m& M N/ z0 m版权声明:tony++ J; C( w$ _ I4 H" v
" n0 T, S( `8 v- l! h8 s. C
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