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在 ARM 端 StarterWare 例程中 CMD 文件比 DSP 端多了这样一句
: a$ B3 a$ b- F+ p$ J/* 重新配置程序入口点 */
& _& c: R2 W; r, V2 `* }4 h-e Entry- /****************************************************************************/0 G# F% o! ^" H" M. l
- /* */
+ m! r4 G9 p- y) f5 C e' e8 _# P - /* OMAPL138 及 DSP C6748 内存空间分配定义 */0 |2 M, M" T( P% e5 G4 G% i( G
- /* */: W1 f: p3 i4 S- U/ _. K2 O
- /* 2015年04月20日 */! O5 b' ~3 w) X! c2 U
- /* */- c1 z* B0 W$ H+ `
- /****************************************************************************/
0 X0 V4 J9 p4 m, m) A - /* 堆栈 */
- G- @1 a! {* P% c - -stack 0x8000
. T8 E/ Z3 |8 e. _7 l4 Z - -heap 0x2000
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- /* 重新配置程序入口点 */; s! W& |3 D) h+ ]9 t
- -e Entry5 t. o% x- O- {) k; [ z
- 9 f* j, R ^) j: H
- MEMORY
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! s5 s# S! h( f" ~( t: R - #ifdef DSP_CORE, e, i! h7 ~" V2 U; o$ m2 Q( S
- /****************************************************************************/
" Y7 C7 [3 |0 C# m - /* */
$ `" |4 f, Q( j- C; l( e - /* DSP 专有内存区域 */
% J, Y" r# b2 C' B/ c% Z - /* */& e% }1 s, L" w6 [8 H! U8 D2 q2 k
- /****************************************************************************/
! V |" n y* a6 h, f# f - DSPL2ROM o = 0x00700000 l = 0x00100000 /* 1MB L2 DSP 本地 ROM (DSP ROM Bootloader) */
, K, _. i2 J3 b. `3 W2 G1 k - DSPL2RAM o = 0x00800000 l = 0x00040000 /* 256kB L2 DSP 本地 RAM */
: \3 f Y; A. B ~7 Q* m1 O2 a) Z - DSPL1PRAM o = 0x00E00000 l = 0x00008000 /* 32kB L1 DSP 本地程序 RAM */ s1 f7 }1 C. c: D) t
- DSPL1DRAM o = 0x00F00000 l = 0x00008000 /* 32kB L1 DSP 本地数据 RAM */
: x/ A+ R: |9 `" L/ V0 S. f - #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
/ r% l5 V5 e- v2 {" {( _' `6 k2 Q- ;******************************************************************************
, [2 N, J( \) J2 }+ x - ;
8 t3 m$ c* }5 S+ |7 F - ; init.asm - Init code routines
: o, x3 n5 L& c - ;
$ j$ O% x7 K/ H* `2 t$ Q6 ~. T - ; Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com/) `& W! I9 }& u
- ; All rights reserved.; ^- U P" Z' \1 a, g, z/ P$ v
- ;% E0 b( x8 i% W( ^
- ;******************************************************************************
! D' I# C( \! @$ Z7 S/ X - ;****************************** Global Symbols*******************************% N8 J0 v7 }7 q4 m1 I5 B
- .global Entry# p1 W' Q! n2 _- R
- .global start_boot
6 k1 C# k+ H2 A- r B* r" d. @; J - .global __TI_auto_init
# ]. c% `( J5 B7 E3 u! [) R4 f/ G+ W - 0 L1 z, U- _4 A! x; N
- .ref __stack
O* ?3 P8 P* h8 t3 J5 Z/ h" o - .ref __STACK_END+ X) T' O" B" I4 S7 w& I$ F
- .ref bss_start
& ^# t6 b4 M1 n! `% \. { - .ref bss_end
( u/ X% @1 b7 N% q; K - .ref start_boot
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- ;************************ Internal Definitions ******************************
# }4 @' f# L9 x9 u5 B! Q - ;/ X2 d1 X. j6 n1 p+ S7 c" K
- ; Define the stack sizes for different modes. The user/system mode will use8 n5 v) y! w+ t. n8 c
- ; the rest of the total stack size
0 w" _4 L/ }" n9 x - ;
* S( L3 z& E5 O! @
2 ^% R/ l' M$ N" X& L- UND_STACK_SIZE .set 0x89 N+ {% e" c& O& _( A
- ABT_STACK_SIZE .set 0x8
3 e( S- s, a; _9 l) |+ v - FIQ_STACK_SIZE .set 0x8
# y- L- u' `% |- J - IRQ_STACK_SIZE .set 0x500
1 e9 q% J# ^8 z - SVC_STACK_SIZE .set 0x81 L$ g: [, R4 y$ x& p
2 F8 o# k- u6 k9 g' R# e- ;
7 V8 i7 j' x5 d W$ A6 H - ; to set the mode bits in CPSR for different modes
) u+ \7 p4 R3 e3 `- t4 q0 p/ F& p - ;. t6 n: H, a: h4 h; |
- * t( c% A5 n# O4 ?7 i _+ D
- MODE_USR .set 0x10
% K5 ?& q8 G F, S, g9 } - MODE_FIQ .set 0x119 z+ T3 B+ {6 l5 q6 {$ Y( ]
- MODE_IRQ .set 0x129 o, F# V5 R2 `4 T" S8 s% s6 z
- MODE_SVC .set 0x131 }2 S2 w5 R3 e9 C d
- MODE_ABT .set 0x17
: F: W. Y' I0 V* r* k- { - MODE_UND .set 0x1B* X o# ?" d( D9 j. r J
- MODE_SYS .set 0x1F
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1 W# \* F5 y* N o& V8 W- I_F_BIT .set 0xC06 R3 C* ]: Q w1 ]9 Q/ Z. k
7 p. d' p- b- |( T( o8 D- ;**************************** Code Seection ***********************************
% n( Y8 Y' P! N2 G) ?% g+ K - .text
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- ;
7 Q5 X# b: C7 @4 B& ~; H4 k - ; This code is assembled for ARM instructions+ c" c8 m0 u1 P6 a8 T' ]
- ;3 p0 D) R* }9 e5 k, D5 a
- .state32; R7 |) h9 D9 \2 W6 Q+ ]1 ]
- f: Z" g8 {0 m2 i- ;******************************************************************************/ d9 ?& l( {" k2 q; t
- ;9 Z' X8 N" L" {* P5 U( r
- ;******************************************************************************. _! r4 c- j+ P- {
- ;
9 M- @/ |/ h0 \* w6 Z - ; The reset handler sets up the stack pointers for all the modes. The FIQ and
9 z( F/ g. r' u2 E - ; IRQ shall be disabled during this. Then, clearthe BSS sections, switch to the }7 z7 t7 w) B0 E! [
- ; main() function., R# j% H; h9 r: @5 } n
- ;
3 x3 ?- {- m) B" g4 P8 g1 B4 c - Entry:
0 H$ o4 t+ _& H8 | - ;
% U4 W, b1 }4 n, g. z2 W - ; Set up the Stack for Undefined mode4 j& E: w- ^' W
- ;
3 i! E7 g9 j$ I" G# V. a - LDR r0, _stackptr ; Read and align the stack pointer6 H5 P. M9 U: l" d7 u e
- SUB r0, r0, #8
. Q) H6 z' f. t, ?4 u - BIC r0, r0, #7
4 {0 z8 I7 i% G# } - MSR cpsr_c, #MODE_UND|I_F_BIT ; switch to undef mode
/ @ A. o: `. o% h) t - MOV sp,r0 ; write the stack pointer$ y4 S S4 o; p5 M! }0 O0 b
- SUB r0, r0, #UND_STACK_SIZE ; give stack space& m- ?1 c. }7 M$ R% S% G
- ;+ j& l# D5 o( f& R& z
- ; Set up the Stack for abort mode
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- MSR cpsr_c, #MODE_ABT|I_F_BIT ; Change to abort mode3 M8 J6 N! N% [! H
- MOV sp, r0 ; write the stack pointer
9 Z, T/ W3 U" b - SUB r0,r0, #ABT_STACK_SIZE ; give stack space
5 ], G8 y0 A. ]0 d" B0 A" R; z$ a - ;
* x, z/ Q+ h5 O7 r0 s* Q - ; Set up the Stack for FIQ mode6 o* m _+ u1 x* _' U! j
- ;
@* I! X, y. C - MSR cpsr_c, #MODE_FIQ|I_F_BIT ; change to FIQ mode7 X9 d" l1 Y6 o) ]2 _
- MOV sp,r0 ; write the stack pointer
+ D5 F+ p& Q, x' Z - SUB r0,r0, #FIQ_STACK_SIZE ; give stack space0 z. j9 Q- n% _/ M0 l1 E
- ;
8 `3 W, H# A7 i3 ~9 L- P - ; Set up the Stack for IRQ mode3 v6 ^/ k; W' ^; f
- ;8 g4 x) Z( H+ m# w
- MSR cpsr_c, #MODE_IRQ|I_F_BIT ; change to IRQ mode
) }& H$ o# C% A, g - MOV sp,r0 ; write the stack pointer
& g& Y0 l2 J( O - SUB r0,r0, #IRQ_STACK_SIZE ; give stack space
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- ; Set up the Stack for SVC mode# X2 ^: p& s4 j9 o! _% \& z
- ;; i* {: C* U2 ~% s/ W
- MSR cpsr_c, #MODE_SVC|I_F_BIT ; change to SVC mode1 D5 t6 `4 _( }4 V) W7 P
- MOV sp,r0 ; write the stack pointer3 }9 ?1 `+ c2 A/ }$ W, Q
- SUB r0,r0, #SVC_STACK_SIZE ; give stack space
) u! a/ ?) a+ j4 v" Q3 ` - ;
( Q6 q }7 {! U3 t5 F6 F - ; Set up the Stack for USer/System mode
: U- U4 s3 K1 g% Z6 E p - ;
% h/ g- U, s0 h& f) a6 l$ ] - MSR cpsr_c, #MODE_SYS|I_F_BIT ; change to system mode4 [& k. B: }. L) a% ?. ?
- MOV sp,r0 ; write the stack pointer
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' }( ?+ i- B& L& n0 E( B- ;
) j& ?! a' N! _0 } - ; Clear the BSS section here7 Y8 g1 l3 k- N+ L
- ;
- b' l' [% T3 |# p3 z5 J9 L - Clear_Bss_Section:
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- LDR r0, _bss_start ; Start address of BSS
3 s- K9 p4 h8 ?8 m - LDR r1, _bss_end ; End address of BSS r+ }4 c e% } q8 r
- SUB r1,r1,#4: h( I. J0 E! ~! B
- MOV r2, #0& f: r7 p, J! }( n& ^7 s
- Loop:, x6 A- z' r: l+ E7 v+ l7 ?& q
- STR r2, [r0], #4 ; Clear one word in BSS9 s9 g3 C$ [& A( C2 V
- CMP r0, r18 z- F. Q. E8 q C5 a A" ^' ~
- BLE Loop ; Clear till BSS end
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- BL __TI_auto_init ; Call TI auto init
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- ; Enter the start_boot function. The execution still happens in system mode7 f9 u, ?- P5 }! ~. a
- ;
& u- ]+ Q, w' Y, h. E - LDR r10, _start_boot ; Get the address of start_boot! G, q+ r, G/ P; x
- MOV lr,pc ; Dummy return 5 d8 C5 C) y7 z' o/ F/ R3 Q8 c
- BX r10 ; Branch to start_boot& b$ n0 q% i4 P. I% G! T) `
- SUB pc, pc, #0x08 ; looping
: |. @8 F# m: k. h, ^" d - ! K; c- K/ j4 L" `
- ; MSR cpsr_c, #MODE_SVC|I_F_BIT ; change to SVC mode
: u6 c( p) O" y$ z; w( M - ; BX lr
" h( {# C' y; @3 K2 `9 s6 k8 X - ;
6 n$ m l" H ^ O - ; End of the file3 X5 {- @& C0 b4 Z5 D3 H9 d
- ;9 U# M, M% h) K5 N R3 o1 A
- 2 W: f( [' M& p& K
- _stackptr:# h7 H1 ?! E" N3 R/ d
- .word __STACK_END
$ V% y7 M9 z( i/ k: S% \3 v - _bss_start:0 k0 e! u* y( x5 X3 b) x8 r
- .word bss_start9 Y% i, ^1 z2 u0 T6 v V6 o
- _bss_end:
3 J/ q6 Y# l) ^+ m! q0 M* B - .word bss_end
0 A# f0 y9 V- Q# I - _start_boot:
* Z; z$ g- g k X( n - .word start_boot+ Y, P) y' O4 y$ N! Z2 j& A
- _data_auto_init:! E) S \0 |8 z* e# v* y9 Y
- .word __TI_auto_init
1 x2 i; D! w q8 p3 K$ z - .end
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复制代码 $ o" a" F! m; X, I' y& }
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