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在 ARM 端 StarterWare 例程中 CMD 文件比 DSP 端多了这样一句- i% x. F& j. V6 z) n' ]8 ~; `
/* 重新配置程序入口点 */! P* p6 l" p* y, h
-e Entry- /****************************************************************************/
" T: t9 g! t% f$ ^, P - /* */
; `# w) ]. @) Z, E6 E$ n. ^ k - /* OMAPL138 及 DSP C6748 内存空间分配定义 */8 ]8 I3 L, q) \, C* x
- /* */ Y8 U3 {+ g* x6 Q
- /* 2015年04月20日 */
! x* d5 J! N0 y* @/ W- }0 X/ A - /* */( m: O K! x4 d
- /****************************************************************************/
' x2 c" z" F- m6 o {; B, s3 l - /* 堆栈 */
7 @3 ?- D+ k4 R% |, C$ ]) Z% v( n/ F - -stack 0x8000
1 N" m$ X1 n) T2 o' f - -heap 0x2000
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- /* 重新配置程序入口点 */
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- MEMORY
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- #ifdef DSP_CORE7 o; J! p( c. K' Z1 G/ @: ?
- /****************************************************************************/
5 |$ x# ~9 {& ?6 B! A6 \ - /* */5 S% b) v& J5 k) k W5 A
- /* DSP 专有内存区域 */+ ^2 L. x9 ^. r) a
- /* */) _ s8 u+ }" Z4 @% w
- /****************************************************************************/
3 {) g7 W9 t: v' @! x" f - DSPL2ROM o = 0x00700000 l = 0x00100000 /* 1MB L2 DSP 本地 ROM (DSP ROM Bootloader) */
2 O9 d% h/ o* h/ x7 w - DSPL2RAM o = 0x00800000 l = 0x00040000 /* 256kB L2 DSP 本地 RAM */
: J1 W+ S% o' N* V3 I* y - DSPL1PRAM o = 0x00E00000 l = 0x00008000 /* 32kB L1 DSP 本地程序 RAM */0 |2 B$ b1 y1 v/ O: W4 |4 z6 W
- DSPL1DRAM o = 0x00F00000 l = 0x00008000 /* 32kB L1 DSP 本地数据 RAM */
- t$ Y1 g: j- N8 l; J# K: i - #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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OMAPL138_StarterWare_1_10_04_01\system_config\armv5\cgt\init.asm/ ?8 ~, x7 O+ t+ q& V% O; Y9 _
- ;******************************************************************************
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- ; init.asm - Init code routines' x7 |2 E6 j5 y, S4 o4 u
- ;; s. t5 s7 z! q" l3 M
- ; Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com/9 M7 k/ I) M' V. G
- ; All rights reserved., x9 m' Q+ A9 o) O- @/ K
- ; u0 v1 S m1 {- l2 ]1 C
- ;******************************************************************************
' H2 N% i* V7 I4 [5 ]( n4 Y - ;****************************** Global Symbols*******************************: r/ `+ y3 D$ U2 s U
- .global Entry+ H8 B% q! h$ ~5 |, s
- .global start_boot3 a' h9 r- r; w: g
- .global __TI_auto_init8 t. `7 @" N" V5 ^* R, s/ C1 D
- O% a' Y7 B; U9 p' ~8 Q/ j- .ref __stack; a( V8 K" u3 J) N
- .ref __STACK_END+ _" i" A @* N" V" q1 W
- .ref bss_start- T) F+ [& p" H
- .ref bss_end$ d# a& X3 u: X4 q1 |
- .ref start_boot8 _* }+ b% j7 H ~, N* s9 a
- n5 I) T1 V8 R+ ]$ e8 J7 o
- ;************************ Internal Definitions ******************************4 M4 ^. m' h- [. Y0 p& b. X/ I
- ;, e: s1 ?7 c4 w7 E& X
- ; Define the stack sizes for different modes. The user/system mode will use: j1 x6 Q$ v. `1 C8 A1 i
- ; the rest of the total stack size
: I1 r2 S3 w5 u8 H& ` - ;
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- UND_STACK_SIZE .set 0x8
$ v- m% t- z* I) \ - ABT_STACK_SIZE .set 0x8. Q" r* [! h5 J8 I$ o$ ?4 r% ~
- FIQ_STACK_SIZE .set 0x8
, r5 Z5 r6 O8 b! J: u - IRQ_STACK_SIZE .set 0x5009 q8 z* x( D0 q" I8 e8 N% d
- SVC_STACK_SIZE .set 0x8
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- ; to set the mode bits in CPSR for different modes2 _. Q3 W0 f# v; R$ O4 j. J
- ;
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: g' [- l# j$ [7 h$ o- MODE_USR .set 0x10
+ F% E% C* Z8 @9 y4 o, O9 ]# V - MODE_FIQ .set 0x11
) t2 B+ A9 ^, H S. f, @* F# v# v - MODE_IRQ .set 0x126 E ]6 r$ ?% d) }; l4 w
- MODE_SVC .set 0x13$ s' e2 u- U6 W4 S
- MODE_ABT .set 0x17
; Z, l& f0 d% P) | - MODE_UND .set 0x1B
+ G) D/ @; E5 X4 m( U& e - MODE_SYS .set 0x1F
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- I_F_BIT .set 0xC0. ^" T- m- k8 x% ?
- 6 P" A1 b8 v+ g9 J- K
- ;**************************** Code Seection ***********************************
, T9 M/ ?+ x2 i$ H3 G6 Z/ b% e - .text
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+ x( p' @! I1 q& k% L( W% Y- ;
3 J/ k- G) c, U - ; This code is assembled for ARM instructions
# ^( ~; e/ N& x+ I - ;) w/ W, l& g. m
- .state32
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- ;******************************************************************************9 g7 } q) f. v$ p
- ;5 o1 u0 T2 V! e- Y
- ;******************************************************************************
! s! A0 e8 R9 P: W/ `9 W - ;8 F( p! N, @$ f3 q) d
- ; The reset handler sets up the stack pointers for all the modes. The FIQ and8 k* z, m0 W( V ?7 t5 l
- ; IRQ shall be disabled during this. Then, clearthe BSS sections, switch to the8 J& ^1 [; l2 v) @- P+ F
- ; main() function.9 i5 J2 d7 J8 |' z" c# i& [* U
- ;- [ a& X; {; `' a; E5 \
- Entry:: [2 P; s- n9 {6 Y
- ;
4 K- X1 w6 C1 M" t- \+ y& x+ R - ; Set up the Stack for Undefined mode0 M* c1 z( K2 Z: Q
- ;% F3 S- {$ f I
- LDR r0, _stackptr ; Read and align the stack pointer
* @6 z* o. _& }1 z - SUB r0, r0, #8
9 G% t. y2 t! y+ ]" x; @. | - BIC r0, r0, #7
# N6 P# S2 o5 t, r2 P - MSR cpsr_c, #MODE_UND|I_F_BIT ; switch to undef mode2 p% h1 U/ R: L
- MOV sp,r0 ; write the stack pointer
' K& Z: B9 C# J1 Z* b - SUB r0, r0, #UND_STACK_SIZE ; give stack space1 C+ y9 }3 a$ w
- ;
Q# e; Y7 ?/ e - ; Set up the Stack for abort mode/ u4 ]$ c; \, C k6 v
- ;6 Y5 K" N6 W1 Y4 [& e/ X
- MSR cpsr_c, #MODE_ABT|I_F_BIT ; Change to abort mode3 x* {$ [5 z+ n1 U, a9 c1 m
- MOV sp, r0 ; write the stack pointer2 R0 ^5 R: p) e( b; r
- SUB r0,r0, #ABT_STACK_SIZE ; give stack space" @9 [$ @! p" m E5 f
- ;
0 {* p4 P: I7 d8 J7 v' n7 a- B - ; Set up the Stack for FIQ mode
6 @0 y* n& j: P/ I- N - ;
- F4 u5 q0 K2 y! o& w3 @ - MSR cpsr_c, #MODE_FIQ|I_F_BIT ; change to FIQ mode% Z- @! T. E/ j5 S6 r( g+ f, `) i
- MOV sp,r0 ; write the stack pointer
- u9 z4 |0 M# s. ^+ T) W: @ - SUB r0,r0, #FIQ_STACK_SIZE ; give stack space. u# z3 q9 O- w- ^6 g
- ;
& d% N. \$ \; G7 B) ~7 G5 R' S - ; Set up the Stack for IRQ mode
i8 N; U, O: @0 L' U* N - ;/ i6 {) D6 I2 G" v. t( |
- MSR cpsr_c, #MODE_IRQ|I_F_BIT ; change to IRQ mode8 ^3 {" {6 o0 V* g- [
- MOV sp,r0 ; write the stack pointer" r; T a6 X: t& k4 Z- e; C- v
- SUB r0,r0, #IRQ_STACK_SIZE ; give stack space
* L+ s. w% b0 ]# t8 w/ r' g - ;$ w# C( @; h/ J: g! g
- ; Set up the Stack for SVC mode/ S, l6 I G) u* |6 m7 D8 b2 B$ N
- ;* t3 d6 u& `2 J! r& T0 O& `
- MSR cpsr_c, #MODE_SVC|I_F_BIT ; change to SVC mode' t( y6 s% d# n* b$ K a6 `; Z0 Z
- MOV sp,r0 ; write the stack pointer6 ]5 }1 J" ^, m
- SUB r0,r0, #SVC_STACK_SIZE ; give stack space
: \9 f7 x' n9 K# \# H - ;
' @. k# i( K! q6 Y8 m. c - ; Set up the Stack for USer/System mode1 o" ~% B0 p* N P, r& k ~1 v' {" b
- ;# W A7 c; a* a4 K; E& ` t
- MSR cpsr_c, #MODE_SYS|I_F_BIT ; change to system mode( x) c e9 @# z$ n8 S% F, r
- MOV sp,r0 ; write the stack pointer
3 e) A4 Y; C4 Z
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- ; Clear the BSS section here2 ^$ D& V+ k0 S# [+ U5 Y9 g! m
- ;
6 w" s' o- ^! @8 @. L - Clear_Bss_Section:' Y' e0 m- Q' }, p. W3 A4 W
) g' p7 U. j! a' f- LDR r0, _bss_start ; Start address of BSS3 o$ L( c: Y6 {
- LDR r1, _bss_end ; End address of BSS! o+ n' y0 } g' D X
- SUB r1,r1,#4% q) X( c: Q0 R. N7 z
- MOV r2, #0
# C. [6 @8 e k- `* |0 Y$ L! u4 s, _ - Loop:
+ T0 } Z* Z* |; D) a; F - STR r2, [r0], #4 ; Clear one word in BSS
! p5 N, H. Q4 _9 F - CMP r0, r1+ e }: ~1 t' H8 i" L
- BLE Loop ; Clear till BSS end
# Z5 E; {- q# ~0 R0 A5 j
8 M9 K$ A1 }/ n* f @" @6 l- BL __TI_auto_init ; Call TI auto init) s8 z- i" C" t
# W- D$ n4 l" z: E6 m- ;; ^/ k, S% D/ J% m
- ; Enter the start_boot function. The execution still happens in system mode
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- LDR r10, _start_boot ; Get the address of start_boot
2 U, s8 l, Z# J - MOV lr,pc ; Dummy return
/ a9 } a1 d( k' [8 x7 M1 e2 B - BX r10 ; Branch to start_boot
' F+ J( U5 u9 ?2 ^6 G& n8 G - SUB pc, pc, #0x08 ; looping% \4 O. I4 r W
- $ `& M& y* g6 }& F! R9 B
- ; MSR cpsr_c, #MODE_SVC|I_F_BIT ; change to SVC mode
, Z/ ]& A( z, F+ t* E - ; BX lr v& d. P0 |- W5 F/ R4 d5 Y
- ; x" W" R, E/ o- _+ P, n, [5 ?% i
- ; End of the file+ R3 g0 ]6 F$ Z/ t
- ;
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8 b! O n% O$ G0 Z- _stackptr:: @- \3 D* c/ I- N: C
- .word __STACK_END
; h( h0 i6 J. L% S - _bss_start:/ E1 [% s, a1 N' n4 f
- .word bss_start& M( B. N, |0 H- }$ D* A$ ?
- _bss_end:; D9 H% Q! F; @' n, l9 ?. U
- .word bss_end
k/ n. ^/ k; m9 Z - _start_boot:* c) i6 ?# d) X0 w+ T
- .word start_boot7 L" q" N% q, C' G3 C
- _data_auto_init:4 @/ L7 C8 z: }$ G% [# l- e
- .word __TI_auto_init
" H8 U. p0 v/ k. ~ - .end
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复制代码
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