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! U$ K9 W$ v$ Z* ~8 t6 z在 ARM 端 StarterWare 例程中 CMD 文件比 DSP 端多了这样一句
% \9 d* s q, i0 Z, l2 Q/* 重新配置程序入口点 */
; i- S' l, T$ Z$ S; k J4 {-e Entry- /****************************************************************************/0 r2 l' z* r9 k( x! s
- /* */
1 F( `4 y2 _( Y" x2 n9 P - /* OMAPL138 及 DSP C6748 内存空间分配定义 */
' @3 }( t/ G/ F6 `' m$ f - /* */
/ F2 m& K4 ?7 l) F7 E. V" ~ - /* 2015年04月20日 */
* t' d- V, w, Z& ]2 S9 |+ [$ w - /* */5 w' R! X5 \9 p9 ]+ t
- /****************************************************************************/# w) U7 z3 W6 E \+ x
- /* 堆栈 */- q1 o6 ~( _& k8 j. }) \
- -stack 0x80008 t* ^8 |, T. E
- -heap 0x2000; t5 N. t; n0 y& H& f
3 n2 J3 b- \2 [$ h" g* ?- /* 重新配置程序入口点 */
* ^* c3 C8 F& }0 G9 x - -e Entry
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- MEMORY; g4 v5 O. |3 \; d8 ?# c$ |% c0 X
- {
! E8 X3 P7 M: G X$ i7 A( E - #ifdef DSP_CORE1 b; j0 H$ I- _3 r" O8 t4 M! [
- /****************************************************************************/
5 d* j& Z/ [4 {6 }0 m2 B - /* */
% g' M8 Y K' W3 ^! a& T0 G - /* DSP 专有内存区域 */
( Y6 K: E' E8 ~: R+ T - /* */
; c2 j, d6 u' N& w v/ z - /****************************************************************************/
6 U8 h2 f% @9 f. h; d - DSPL2ROM o = 0x00700000 l = 0x00100000 /* 1MB L2 DSP 本地 ROM (DSP ROM Bootloader) */
& X- K2 \0 ]: @! r3 I0 `; L- I - DSPL2RAM o = 0x00800000 l = 0x00040000 /* 256kB L2 DSP 本地 RAM */
/ ^! P+ i9 {( J1 z8 R - DSPL1PRAM o = 0x00E00000 l = 0x00008000 /* 32kB L1 DSP 本地程序 RAM */3 x* n3 D' j; z7 @
- DSPL1DRAM o = 0x00F00000 l = 0x00008000 /* 32kB L1 DSP 本地数据 RAM */
& r4 k8 f, s% d: { - #endif
复制代码 这是一段汇编代码用于切换到特权模式
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L! x3 s9 f c- `' |8 c# YOMAPL138_StarterWare_1_10_04_01\system_config\armv5\cgt\init.asm( o" ^. j$ p6 U& {
- ;******************************************************************************
1 T [9 F7 B2 v3 k0 O6 C4 k* z0 D - ;
8 |$ c2 R* M% C: m, F - ; init.asm - Init code routines+ W7 }# K- u+ T! Q2 h
- ;
w5 _( |! L$ K" [5 T - ; Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com/2 U- \ X0 m( S' N a
- ; All rights reserved.# s. ~- C% }) O, h& g) r
- ;
5 F7 S' B* b. I. |% b- {, r - ;******************************************************************************
- t/ Q8 ^7 S0 q% n0 c; [ - ;****************************** Global Symbols*******************************
" n5 ?4 y0 {/ S8 V0 T* z - .global Entry l, h: r* A* [" s
- .global start_boot# x& F' u% e ?$ C, k0 F: C
- .global __TI_auto_init
" J% l7 d `. |
) H8 E/ j$ H X$ k0 J3 }/ b, q4 Z8 q- .ref __stack* H+ c8 r9 o2 a
- .ref __STACK_END
- n1 p y9 t+ d - .ref bss_start
9 b. c; t R& s6 p1 Y - .ref bss_end" W# ?- ]" O/ K0 ]; T$ @
- .ref start_boot
; ~3 s- S$ q" m5 b5 |
+ T& A# V9 _) p/ Q5 n: q5 J- ;************************ Internal Definitions ******************************9 V: `( F+ i& r
- ;
2 T3 s# A o$ x' x% l9 \ - ; Define the stack sizes for different modes. The user/system mode will use+ w* y. e. Y3 F5 v8 v. r) e
- ; the rest of the total stack size
" y/ M' b: X. t6 @( A/ L - ;
8 j) L3 ^$ w! q T R: E6 f8 C - 0 ^# [% _, @- J
- UND_STACK_SIZE .set 0x80 I6 m; c' s# D# G! i
- ABT_STACK_SIZE .set 0x8
% V4 l- F6 r# b. g& |7 b/ q6 s - FIQ_STACK_SIZE .set 0x81 J9 g3 `' F! \
- IRQ_STACK_SIZE .set 0x500
" W) ?& R1 R0 Z1 e) N2 m3 M, V - SVC_STACK_SIZE .set 0x89 Y9 I& v! z5 p5 R6 }+ O
- b8 w! T; M% u) s+ u8 m4 ~( P' m- ;3 X! I+ |3 o' G( O: m2 `( s( b
- ; to set the mode bits in CPSR for different modes- A8 Q( \. a. l$ j' y
- ;$ _- ^6 {8 a2 v& b' T! t/ |
0 C2 W, p1 ^. n4 P/ C+ m' t& r- MODE_USR .set 0x10! L a( g) F2 [4 Z5 ?* r* P! g: F
- MODE_FIQ .set 0x11
& ^, a* V) Y9 I% g - MODE_IRQ .set 0x12" D8 L0 d, ^( T* g$ S- d4 M: g+ n
- MODE_SVC .set 0x134 }3 I) v. A. R' Q/ E4 X
- MODE_ABT .set 0x17* m! T; T2 L- m& e% `" u
- MODE_UND .set 0x1B
7 `) U0 I3 b$ D - MODE_SYS .set 0x1F
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- I_F_BIT .set 0xC0" x2 q& S& P8 i* c. w
- " S& Q0 L K# ?( Z/ M# Y
- ;**************************** Code Seection ************************************ Q4 ~0 Q6 h$ _% v1 C, b% d8 e1 R
- .text" ]8 o- t( n, y/ d' A# }
- 5 d; C# s# X0 o$ ]8 Y! V2 d/ r
- ;" c9 b: n9 H t9 x' f$ p
- ; This code is assembled for ARM instructions
7 z( i! C- D9 ^8 w( e9 m) M - ;. b% P2 w. g2 n; M; A' t( V2 s
- .state328 v; E3 ~7 @; P8 d7 t7 R
$ B. B8 m$ g; t6 m1 K3 D- ;******************************************************************************/ L3 j/ `$ n. ^! k/ ^
- ;" D4 b2 b# _3 {9 j, h1 S" G. K7 W
- ;******************************************************************************
; }, C; F7 d' t7 x \ - ;
( `8 |* F4 f) n: e3 z - ; The reset handler sets up the stack pointers for all the modes. The FIQ and
3 h) d' {. g) l/ v; D - ; IRQ shall be disabled during this. Then, clearthe BSS sections, switch to the8 H: ]; y& `3 F
- ; main() function. h3 s: ]6 r6 {% h* L B
- ;
- C5 L0 x/ N" }5 T3 b - Entry:
: f, C4 p) C3 p% d, N9 y6 U0 H - ;3 Y! n. a X2 N& g! U9 d
- ; Set up the Stack for Undefined mode
8 s4 I4 y W$ e& `" \* ~ - ;- ]9 |: o( Y4 x# f2 g' m$ d
- LDR r0, _stackptr ; Read and align the stack pointer V' e! k8 }7 p( o: [) Q
- SUB r0, r0, #8
+ p- i4 Y# a+ q/ n) t6 Y% L% \8 r - BIC r0, r0, #7
# @. v! s* a: A/ J+ g9 D - MSR cpsr_c, #MODE_UND|I_F_BIT ; switch to undef mode. E! k0 {( J2 |! O8 o2 Y1 S
- MOV sp,r0 ; write the stack pointer
8 `$ B2 E6 s6 S* h% h5 ?/ f - SUB r0, r0, #UND_STACK_SIZE ; give stack space7 D) {! q# b+ }2 T$ a& _! S' C
- ;
( P0 D% ?3 ?7 w1 t2 h/ s - ; Set up the Stack for abort mode* l/ m* y* r4 F
- ;
, J7 T" E. c& q( W5 B - MSR cpsr_c, #MODE_ABT|I_F_BIT ; Change to abort mode
) ?% M# U" G1 @ - MOV sp, r0 ; write the stack pointer
( W/ S6 a( L% T1 t: w! k4 s - SUB r0,r0, #ABT_STACK_SIZE ; give stack space' Q/ j$ I8 |- J0 d: ]- I( p3 Z4 d
- ;2 }2 M5 }2 x) N+ p' b) h
- ; Set up the Stack for FIQ mode7 l& j9 A( Z! C# u {
- ;3 O5 F, k, K; Q
- MSR cpsr_c, #MODE_FIQ|I_F_BIT ; change to FIQ mode/ B. x# f5 i5 |: a, J# x" m
- MOV sp,r0 ; write the stack pointer
1 g: b8 W+ P; d& @) s& M( o - SUB r0,r0, #FIQ_STACK_SIZE ; give stack space$ ?& U5 b9 f& d
- ;
7 I# | U8 e2 B$ Y! ^ - ; Set up the Stack for IRQ mode
# X% j9 U+ W9 ?) l& L* u' b - ;
7 y" {/ V: R) R# |8 \9 ^. E. b - MSR cpsr_c, #MODE_IRQ|I_F_BIT ; change to IRQ mode
4 {% P/ L' g& L& }/ h( F/ \ U - MOV sp,r0 ; write the stack pointer" c5 }" |6 s; _$ s
- SUB r0,r0, #IRQ_STACK_SIZE ; give stack space
( w( ~5 _: o0 Z5 N, L7 K - ;
Y: F) s) Z2 C i4 \5 C% ` - ; Set up the Stack for SVC mode$ D) W E0 u9 n8 {. Z
- ;1 _% I0 Y0 [0 r, i
- MSR cpsr_c, #MODE_SVC|I_F_BIT ; change to SVC mode
+ w" _+ z) Z& z0 Y% ]3 v; c - MOV sp,r0 ; write the stack pointer
/ g2 Y/ d# x2 A( u- N& m8 k) D" T- X - SUB r0,r0, #SVC_STACK_SIZE ; give stack space
" x, g7 m; N7 f) {) |7 X - ;
7 Z) Z, u8 G2 N- _* W - ; Set up the Stack for USer/System mode4 V, H) X: ?( @* o! E2 H8 z- L0 Z
- ;0 p4 n) e* U3 D: z' w4 P
- MSR cpsr_c, #MODE_SYS|I_F_BIT ; change to system mode
+ K) B8 j) I" w# w - MOV sp,r0 ; write the stack pointer3 f6 z5 C* Q( H& V
# v- p2 S, h% u1 c! e- ;
$ R: q1 ^0 s0 S0 T5 |. W: b: w - ; Clear the BSS section here$ X' j: ]! O! a. o) l
- ;
" t1 \6 W' Q5 o/ T' N - Clear_Bss_Section:
, w) j* w2 k( |6 j. I9 x
' e0 B6 Y& f2 z; M! S- LDR r0, _bss_start ; Start address of BSS' [( H0 f8 ]2 e7 {; e- X
- LDR r1, _bss_end ; End address of BSS3 K- ]% [8 n4 M5 P1 s
- SUB r1,r1,#4) `8 N8 J8 L5 X# Z. V9 g3 M
- MOV r2, #0- c8 T8 \: v8 Z% l# _
- Loop:' {) r4 c" G' r
- STR r2, [r0], #4 ; Clear one word in BSS- B; F/ g. F" V {7 {" k
- CMP r0, r1
! x" l+ J: u5 g - BLE Loop ; Clear till BSS end9 m" h/ i" T$ a$ M- [' o: o
- - @9 s" U* G0 K L' T! x% |
- BL __TI_auto_init ; Call TI auto init# t3 Z( V& ]; w! W
- 9 b, _6 L* A! V' @# Z9 i n( F) _
- ;" } q9 {: I' Z+ b- L$ a; k
- ; Enter the start_boot function. The execution still happens in system mode
: d! I3 d H8 j- `5 | \ - ;
0 O, p- n: S$ |4 T+ ]& B6 J - LDR r10, _start_boot ; Get the address of start_boot3 S2 p# m& i: V9 y
- MOV lr,pc ; Dummy return
9 h0 j# j9 Q) ?, e - BX r10 ; Branch to start_boot& t! g9 S2 f- q; `( f; h$ D' p
- SUB pc, pc, #0x08 ; looping
& q9 Y, a% U1 w& p0 x# Q R - + j6 R3 o. H/ q/ T0 L
- ; MSR cpsr_c, #MODE_SVC|I_F_BIT ; change to SVC mode& \. Q( `- ^3 Z- y& A/ e
- ; BX lr
* ~2 @( i3 m# D2 X! B5 g, Y4 P( M - ;
6 ^5 g4 O5 J6 R3 a) P' Q - ; End of the file
9 \) m* m1 @6 B* }' O3 f. E - ;
! e/ [- ~7 u. }; L, n
0 k4 ]3 a( ^2 N- _stackptr:9 X4 h, e' ~% c1 ^7 F
- .word __STACK_END
( s% V% I9 Z2 Z: P W: @6 c - _bss_start:9 d: e# Y/ ?+ L2 t* `, t9 t8 L- I. F, T
- .word bss_start
0 {# }5 }6 _+ j3 P! l6 A% T - _bss_end:
) Y5 R, z1 p. c( P9 K1 O/ e) Y - .word bss_end
/ |8 S; C& F+ T4 y - _start_boot:# }0 G( J; m# g% E& c; r
- .word start_boot
+ W# a4 }4 d& f8 d" C7 `2 ? - _data_auto_init:
! f4 u$ y9 c- V8 x - .word __TI_auto_init1 _0 @$ ^' u; \" c0 @/ i [# v
- .end& E/ Z3 t h0 N) x
- ' x9 a: {* q& R1 d G& H
- 0 v( ?9 f9 C* Z/ g
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