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' |$ y+ Y. T* `8 M' L在 ARM 端 StarterWare 例程中 CMD 文件比 DSP 端多了这样一句
7 g, d$ Z3 i& U% L6 C% p* O6 h/* 重新配置程序入口点 */
9 U9 F/ _2 S& {3 J5 [1 U8 |& k-e Entry- /****************************************************************************/+ C# y% _5 |# D' ~
- /* */
/ z( G( i3 Z7 b+ Q: u K - /* OMAPL138 及 DSP C6748 内存空间分配定义 */ G9 L! r1 I/ [4 n- q/ _; q
- /* */; _ I% a" E! F+ N+ i
- /* 2015年04月20日 */, E# o9 i+ Z2 t2 G4 ]4 |
- /* */" N+ X7 S/ H0 ]) w7 G7 I H
- /****************************************************************************/
' O6 @8 o2 Z$ V; H& m" e0 V) P) I- c - /* 堆栈 *// ]5 {' @( ^, h9 r* J. j4 I
- -stack 0x8000
# d- G0 ^: E6 G: ` v" n8 M$ p - -heap 0x2000
! l/ _ J+ ~' x( F - . R( M9 i4 _7 X2 Q1 r' o# O( H
- /* 重新配置程序入口点 */# e/ ]4 J( `/ [: }: n2 |& Y! E' q
- -e Entry
- y# y% Q/ Q$ u
: h1 D2 M/ D( R- MEMORY
* C- H; G0 e( N' v( j5 E) t - {4 ~4 D1 [$ _$ R1 ]
- #ifdef DSP_CORE7 n: l3 {' b3 u% l
- /****************************************************************************/: g9 ~; S: o w' ^2 d& i; @- v4 V
- /* */
% c q! @& ` w% M# B; S0 n4 Q - /* DSP 专有内存区域 */1 @3 \/ ]5 L! |; i* r% f
- /* */" H. P) Z% L2 [/ F: O; \
- /****************************************************************************/
$ g, _% R$ Z8 ]( S4 j! @0 U, N9 x( L - DSPL2ROM o = 0x00700000 l = 0x00100000 /* 1MB L2 DSP 本地 ROM (DSP ROM Bootloader) */
5 X0 |2 a+ L+ b. w# ] - DSPL2RAM o = 0x00800000 l = 0x00040000 /* 256kB L2 DSP 本地 RAM */* s9 _) h9 z: d) F0 r N* C
- DSPL1PRAM o = 0x00E00000 l = 0x00008000 /* 32kB L1 DSP 本地程序 RAM */
K: Q/ N4 }& G5 a: f h - DSPL1DRAM o = 0x00F00000 l = 0x00008000 /* 32kB L1 DSP 本地数据 RAM */
) L. H0 L- g, u" ]# z - #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.asm7 r5 t; t" G2 ?% c* A9 I- p
- ;******************************************************************************$ E% g# y6 @& {4 C
- ;8 r7 Z5 P$ |" t- w3 G1 ~
- ; init.asm - Init code routines- y7 u: `6 C! ~) q
- ;
" d/ l8 q( l2 }' M - ; Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com/% ?. o8 a8 c& E: c7 O& c1 t& O
- ; All rights reserved.0 U. B% u. u$ b5 `+ O
- ;6 W5 @( @& H$ O" X
- ;******************************************************************************3 D2 F5 \2 {0 y, t! a# p3 A
- ;****************************** Global Symbols*******************************1 |) W; [2 d9 e9 ]( K9 Y" h/ @$ _
- .global Entry
% T" v! @3 Q7 c1 E$ u; W; J - .global start_boot
$ N+ `3 k6 H8 S. Z0 g0 J) E: H. A - .global __TI_auto_init
$ V( m1 ?9 J' Y1 x - 9 l8 M7 k9 T' i$ |
- .ref __stack
6 t { h f$ J8 C0 o' c/ Z2 ] - .ref __STACK_END
# G* u* U7 t9 k+ Z - .ref bss_start h) @- d2 ~7 {# _* C# h
- .ref bss_end
" h/ v, Q; v, i - .ref start_boot3 o! `1 I" i) w/ z7 G7 E
- 1 \1 e. V" w- x* N
- ;************************ Internal Definitions ******************************- |5 X6 B- b7 D5 g0 J2 Q
- ;
J4 {0 j6 z7 K- T9 e. g5 ] - ; Define the stack sizes for different modes. The user/system mode will use/ q- R8 e# Y0 I. x* M3 K- ~% ]( o
- ; the rest of the total stack size9 k8 N. L( q/ L. y# L# R! h9 q
- ;6 `, P3 D: [: s2 |2 `
* Z) v8 W z/ P; C, e- UND_STACK_SIZE .set 0x8
8 A# \! g# ^; x" b. G) f* a - ABT_STACK_SIZE .set 0x8) A2 D- ~5 A# @% W: M9 ? x
- FIQ_STACK_SIZE .set 0x8+ a2 c+ s8 m& d
- IRQ_STACK_SIZE .set 0x5002 l) i m" N" I3 T
- SVC_STACK_SIZE .set 0x8- M7 F- Q$ g" U4 }6 X
- 5 m7 y9 l+ x6 N2 o Z& f0 t8 L
- ;: j9 P1 N, K: {) I% _' z# A, _
- ; to set the mode bits in CPSR for different modes
0 T* o* @7 |3 c3 Z) L$ j - ;
+ D2 z# o" l# @) h" s9 @& j - ' z6 l# O5 d1 z" c" r
- MODE_USR .set 0x10
3 W7 R1 @) _0 l2 v4 a% C( a - MODE_FIQ .set 0x11' _. l$ l+ Z. h) L, G f
- MODE_IRQ .set 0x12/ `! Y$ b% c, l6 V- i: O$ e
- MODE_SVC .set 0x13
! w! @8 b- ^+ o0 a* B - MODE_ABT .set 0x17
! {* n" s- h' K0 V& I - MODE_UND .set 0x1B
8 M6 K# R r( ~ - MODE_SYS .set 0x1F
- y8 _. ?" B. t2 h c$ ~
5 x7 o3 ~& Q, N% a: f+ `- I_F_BIT .set 0xC08 m, @1 O# @4 B
- 2 L/ H9 b4 k, g" C
- ;**************************** Code Seection ***********************************
# C' Z* G3 t: l, I% }$ s# G - .text& j+ r# a/ v- m8 Z* g! F$ o0 p
- : W7 J' B+ Y5 b' o. t* V
- ;
3 S$ m* b; l& D7 |3 [: }+ ~) t$ p - ; This code is assembled for ARM instructions6 z* C5 t# q, K+ h/ R
- ;" B r- j C" t; R4 o
- .state32+ n. E& D* a; |9 g" Y% A$ x8 B2 f
7 J4 U' Q; t( e$ T8 U+ q, j- ;******************************************************************************: M; E6 B- e( N4 w2 H
- ;
( j2 M8 _ O$ Y3 M2 T \ - ;******************************************************************************
0 C3 O/ ]& v+ \) ? E, F - ;* A2 r0 D+ G2 s4 `2 \* q
- ; The reset handler sets up the stack pointers for all the modes. The FIQ and/ i. D, C/ u! l$ f% f8 ^. r
- ; IRQ shall be disabled during this. Then, clearthe BSS sections, switch to the
+ q0 w; i8 u5 S& e# @ - ; main() function.% X8 Z' ~5 o* ` p8 U! ]) R
- ;$ V; ]+ V! U; X r. |- u
- Entry:
- p$ A9 `" [, f6 R( u - ;! p! F* `& o- B! A6 ?, d( H, z! I
- ; Set up the Stack for Undefined mode
5 R7 ~7 j- {; q& m1 b - ;
1 J8 ~0 d8 t% ^% }, F8 Q4 r! c% p - LDR r0, _stackptr ; Read and align the stack pointer* ]1 _6 l& r. A3 z3 L* Z* y5 a
- SUB r0, r0, #8
9 |7 ?3 S! F- e2 D/ R$ j) o9 O - BIC r0, r0, #7
3 O8 K3 k1 | U7 V$ I - MSR cpsr_c, #MODE_UND|I_F_BIT ; switch to undef mode
' g* r1 Q2 v6 s0 x - MOV sp,r0 ; write the stack pointer0 _+ S9 Q% `4 S: ?6 k
- SUB r0, r0, #UND_STACK_SIZE ; give stack space5 [& | M" t# a1 L0 e0 s
- ;
b% s* R) p+ @2 R - ; Set up the Stack for abort mode2 F' R) n. t; i4 z% ?
- ;
/ F7 u8 }$ }7 n4 @3 a% ~ - MSR cpsr_c, #MODE_ABT|I_F_BIT ; Change to abort mode- M$ F3 e+ n+ o8 ?: w
- MOV sp, r0 ; write the stack pointer$ U j( X/ W8 `7 t& Q4 T% S) {
- SUB r0,r0, #ABT_STACK_SIZE ; give stack space
s( C, ? g' n - ;6 r- X- E2 X9 c: Q' T1 t& V' o
- ; Set up the Stack for FIQ mode
+ o: W5 E6 d6 R' N, L6 U* V - ;
( Q9 U* V+ _% I' c% N* ~7 o5 G - MSR cpsr_c, #MODE_FIQ|I_F_BIT ; change to FIQ mode7 h8 ]* y& K& v; \: b r1 v
- MOV sp,r0 ; write the stack pointer
/ `' [; W o% ^* c - SUB r0,r0, #FIQ_STACK_SIZE ; give stack space4 q* N! G0 b) ^: i1 Z
- ;7 |; n' t6 M- E/ C0 r9 ?. j
- ; Set up the Stack for IRQ mode( _7 |% z; O7 Y
- ;9 n2 \/ w/ b/ n& F, L% _
- MSR cpsr_c, #MODE_IRQ|I_F_BIT ; change to IRQ mode2 J3 F2 a0 M. l% B, q" a( B
- MOV sp,r0 ; write the stack pointer
7 ~% E) g: \8 J8 g H6 s - SUB r0,r0, #IRQ_STACK_SIZE ; give stack space
1 X% ~) I: t. k2 G( h1 q& f - ;1 d+ a4 K1 I9 m- z2 F1 b' ?
- ; Set up the Stack for SVC mode
$ i0 s5 B- t& g' j) F# I; W* k - ;
. Y( v) W7 p P8 F - MSR cpsr_c, #MODE_SVC|I_F_BIT ; change to SVC mode1 G6 l1 p! K* I' O3 w
- MOV sp,r0 ; write the stack pointer
% Q% F/ M. \0 w* r9 A - SUB r0,r0, #SVC_STACK_SIZE ; give stack space! ?8 M6 n: @ i$ g
- ;, h. W& X1 n: Z$ W4 Q1 |
- ; Set up the Stack for USer/System mode8 p9 L0 r/ ]) L. a" K- {1 ~: l
- ;( K5 B! y0 \3 P+ u- U
- MSR cpsr_c, #MODE_SYS|I_F_BIT ; change to system mode' C& J8 ?1 D2 [7 O/ {! m4 }
- MOV sp,r0 ; write the stack pointer8 m# \- I. C; P7 ?) J
- @% R( f4 D R2 d& e
- ;
9 f+ x5 G) u6 B3 b$ k& l& }' M! x - ; Clear the BSS section here
* z5 K) W8 T6 s2 [4 N1 A+ l" j - ;
5 \! Z" S- J8 B: U1 J2 E - Clear_Bss_Section:* ~ x& l" t8 r k0 I
/ A$ a3 t; w& T- LDR r0, _bss_start ; Start address of BSS
& t: \) q0 l# W4 F% `4 y% t - LDR r1, _bss_end ; End address of BSS. U8 S9 O+ c, W2 |/ o q# t3 Y0 n
- SUB r1,r1,#4* i7 o# C7 G" A7 Z; A
- MOV r2, #0
5 o4 Z4 J9 q' G# M) a* Y - Loop:- o2 L& m" h3 G7 s
- STR r2, [r0], #4 ; Clear one word in BSS/ K8 y" {* J- ~5 d8 K
- CMP r0, r1/ k; T" o9 U! U5 g3 i) Z
- BLE Loop ; Clear till BSS end; N a5 |4 X; v; _( E
. O# F5 y4 J, g/ z( D3 i- BL __TI_auto_init ; Call TI auto init$ ]+ S2 Y# Z2 r* X$ ^% N1 U4 ~
- 7 ^# {4 M8 `; f) y7 E- T
- ;
6 d( k: o& @) I3 {* U f - ; Enter the start_boot function. The execution still happens in system mode1 ~: r/ I1 e+ x
- ;
^$ @, M* B5 S2 n9 y - LDR r10, _start_boot ; Get the address of start_boot
. o: w% T2 H6 m - MOV lr,pc ; Dummy return
|+ O8 C- K8 v) O9 j - BX r10 ; Branch to start_boot
' k* c& f: | w2 P - SUB pc, pc, #0x08 ; looping( Y2 ? U) w5 j2 o9 K' e1 G- h
4 o( S) P+ w2 B$ {6 e- ; MSR cpsr_c, #MODE_SVC|I_F_BIT ; change to SVC mode
1 u7 E6 `! j2 J7 A/ d - ; BX lr
, O3 B' P& {) Y - ;
+ i/ C$ S- B2 f( e N B) h/ O8 k( G$ u - ; End of the file! _2 x- G2 J3 X* Q& I0 L0 Q6 Q8 `7 i
- ;
4 n- W7 x8 U& r% l# W4 U7 N0 D - / B1 ] t0 e' X+ q3 D
- _stackptr:# l: N R. ~ x" v; f* \6 ~" q
- .word __STACK_END
& [) E( n# Z. Z U3 X - _bss_start:
/ i2 z9 W" i+ v. a - .word bss_start
4 y2 |* q4 ~: | | - _bss_end:
8 J* I3 m* ^9 { F# _. a - .word bss_end
4 t- _" q4 V0 z - _start_boot:/ K; M+ u: H0 C) l) U
- .word start_boot2 x7 C5 Z$ i( u, L' B7 z" Q. ?
- _data_auto_init:
" V/ F, y! p1 r. H: R# w - .word __TI_auto_init
7 ~) L* E: A. y4 z+ b& Q - .end& N' h, t, o9 B1 I( f
- ! p2 k, h8 D$ T4 r% x" f6 M4 }
. L, @6 b3 g( e* y. j8 }
4 X) s4 `: k6 P/ Y/ n
复制代码 5 W' n& g; I7 }1 _& |
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