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在 ARM 端 StarterWare 例程中 CMD 文件比 DSP 端多了这样一句+ H. ~6 k+ g- J5 j
/* 重新配置程序入口点 */" W- r r" N* }$ O
-e Entry- /****************************************************************************/# ]) x. S) p( @
- /* */0 D/ n' P9 |* G+ w. {; y% B
- /* OMAPL138 及 DSP C6748 内存空间分配定义 */
( c2 k" X) ~$ r! R8 j- G6 c+ u - /* *// w" k' T: J. o( b! b3 i
- /* 2015年04月20日 */" H8 U8 a' \. o0 f4 k7 e( _3 y) W
- /* */' [, I# x4 D& a7 G2 Q' Z0 s
- /****************************************************************************/0 {7 L: ]+ t' G9 @8 ~, Z
- /* 堆栈 */
* V- s4 ~* d5 K% A9 H2 Z0 H4 b4 P0 W9 Z - -stack 0x8000( m2 t4 [/ n! ]4 V, X$ U
- -heap 0x2000& ]( W. a4 j/ a" k6 Y( g
6 U: h @( s- ?4 [0 T( T. R- /* 重新配置程序入口点 */
/ K, ~) h/ X2 b5 d) }- \) l - -e Entry% D a8 d) [+ `. N
: M5 b6 d' v2 s+ }- MEMORY
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) a; A% l/ ~6 ^% A5 r - #ifdef DSP_CORE5 k3 [( e3 y! ?% l6 {
- /****************************************************************************/2 W8 u2 z4 k% @' q; P
- /* */. f5 S/ c; U4 I' P' h% o2 ^9 Z
- /* DSP 专有内存区域 */1 H# O) w% P- g4 T' L3 v) T
- /* */
+ G+ Y. J5 j/ |1 P2 v! }" _ - /****************************************************************************/
7 x: W5 }) C. u - DSPL2ROM o = 0x00700000 l = 0x00100000 /* 1MB L2 DSP 本地 ROM (DSP ROM Bootloader) */
5 t! {4 U0 B5 B- U - DSPL2RAM o = 0x00800000 l = 0x00040000 /* 256kB L2 DSP 本地 RAM */# i) ^( Y6 h; l9 M- X
- DSPL1PRAM o = 0x00E00000 l = 0x00008000 /* 32kB L1 DSP 本地程序 RAM */
3 X5 H$ T6 J3 V6 U - DSPL1DRAM o = 0x00F00000 l = 0x00008000 /* 32kB L1 DSP 本地数据 RAM */
! h" M0 r+ M* `8 G0 u) R - #endif
复制代码 这是一段汇编代码用于切换到特权模式* y1 \/ q; c% v, S: e S* |8 C6 d
( i' {% A) H- F1 a6 v3 X4 aOMAPL138_StarterWare_1_10_04_01\system_config\armv5\cgt\init.asm9 O4 \' u$ p( |' D. t1 Y
- ;******************************************************************************
/ Q( e3 P: l! J& F' p - ;
( j$ W$ ~) }, Q& K6 s - ; init.asm - Init code routines+ ]( g& U( T( Y2 U6 s
- ;
! s5 u$ Q! O; @1 F9 a( Q - ; Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com/
6 f5 G2 G# x! x/ z4 v" Y4 w - ; All rights reserved.# L- _" c- G* S( B6 G6 u
- ;4 h5 j! [" [' D( J
- ;******************************************************************************
, _0 X* ^# l. I4 B" C2 \ - ;****************************** Global Symbols*******************************
) i6 U& e- v7 Z5 u - .global Entry2 X4 Z' o( p" W! Q6 Z/ t3 A& s5 z
- .global start_boot
8 G( P% ~* T+ m: j - .global __TI_auto_init! I }4 I, P& t+ ?. l. k! M
0 J$ `! J8 y4 M6 |- .ref __stack4 H+ q8 H) ]% w6 ?0 A" k, f6 D, O/ a. o
- .ref __STACK_END) [$ N7 V7 a9 n! d" h' F& i
- .ref bss_start
- n9 K% `9 q" \5 `$ H1 J. w1 ^0 j - .ref bss_end! t4 N- m5 R& a
- .ref start_boot
) y6 M& d, M) g9 \& [1 ]
9 }( h+ `8 B) M0 B! u% P- ;************************ Internal Definitions ******************************2 ]3 V* k$ U5 w* h, [% S
- ;. T# o; d8 P. _; G6 P' q' C
- ; Define the stack sizes for different modes. The user/system mode will use4 a8 {+ C Y9 q/ {1 k
- ; the rest of the total stack size* {8 K; m3 e' J) u' x, Y) b
- ;
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- UND_STACK_SIZE .set 0x8$ |. i2 y" _9 R9 K# P
- ABT_STACK_SIZE .set 0x8$ Y0 H* E, V7 P- S, y" P Z
- FIQ_STACK_SIZE .set 0x8
$ P( W; t$ `. g. Q- Y D+ H Y4 d - IRQ_STACK_SIZE .set 0x500% D N' ^8 a2 F5 l, b
- SVC_STACK_SIZE .set 0x8
# K2 C3 |5 j* z - 8 G4 D) K" }, y1 v9 a
- ;5 ^. d4 T U+ l& P: }+ ~! j$ V
- ; to set the mode bits in CPSR for different modes
& ^2 G# J! D$ i2 P - ;
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- MODE_USR .set 0x103 K9 d6 U; w% B4 d/ c u1 N: v
- MODE_FIQ .set 0x11: n1 n- W0 q" Y& r$ z$ N
- MODE_IRQ .set 0x124 e) g) Z1 S6 r' {. o
- MODE_SVC .set 0x13; U" E8 W6 F: M. j- U. x, c
- MODE_ABT .set 0x17) u, M, Z* s/ w
- MODE_UND .set 0x1B3 L1 G& u1 j: u
- MODE_SYS .set 0x1F
# j6 T F7 U: B" M% Z
1 M, `5 o2 K X4 e7 n- I_F_BIT .set 0xC0
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- ;**************************** Code Seection ***********************************+ g9 x8 z7 O9 z* Z Z- |+ [; {; i* s& d
- .text
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- ;
; ]: L% I5 ^1 i# U, J# I" @ - ; This code is assembled for ARM instructions
& m3 p, A: e; ?0 Z6 w; N$ t. h - ;
2 o9 B, S' p& J - .state323 z( J! k. s2 B
- 2 z; s' B# L( G0 \$ }; A
- ;******************************************************************************1 c' d- j$ p8 q* k& v. l
- ;
% s# D5 ^9 L3 R! z5 M - ;******************************************************************************
# O5 U: d/ F) g - ;
2 r; ^9 B! O7 E3 Y - ; The reset handler sets up the stack pointers for all the modes. The FIQ and
; O) N8 {9 k4 ~ - ; IRQ shall be disabled during this. Then, clearthe BSS sections, switch to the+ J0 x. [6 t1 }% x
- ; main() function.
1 E- o% R! P5 r - ;
6 _$ `$ t" \3 G- L - Entry:
a, n; a" t) N$ W. z% J7 H* J2 t - ;6 k% ]" W" Y" ~2 S/ X/ x
- ; Set up the Stack for Undefined mode! y# U: v7 `" ?% S5 j
- ;- e' f7 r6 v. Y4 T/ G- Y3 G& \
- LDR r0, _stackptr ; Read and align the stack pointer1 b/ e8 H$ {$ {% `( {
- SUB r0, r0, #8
& J% i5 S0 D5 y, E - BIC r0, r0, #7
7 a6 z1 c/ ^3 {9 u6 k - MSR cpsr_c, #MODE_UND|I_F_BIT ; switch to undef mode0 @% c( i3 N. R& E& p
- MOV sp,r0 ; write the stack pointer& d: h3 u7 T# H+ E, q& P( U
- SUB r0, r0, #UND_STACK_SIZE ; give stack space" J3 Y: }% h% G9 z7 a0 |0 X
- ;
" X! K# B" u- P6 L1 M& | - ; Set up the Stack for abort mode
9 S* a0 S1 g9 k% W - ;
* s3 u; c* T2 }; i) X4 V c - MSR cpsr_c, #MODE_ABT|I_F_BIT ; Change to abort mode
9 l1 a9 Q9 y8 \. I: n F - MOV sp, r0 ; write the stack pointer( I3 q: L/ v, B% o% D3 f
- SUB r0,r0, #ABT_STACK_SIZE ; give stack space
. P# P/ D: O- z+ c8 B# y - ;
# P I- ^4 Q* ?* P - ; Set up the Stack for FIQ mode
3 D, D; t8 l/ Y* b - ;# @0 x$ ~. z! ^+ b' x6 i
- MSR cpsr_c, #MODE_FIQ|I_F_BIT ; change to FIQ mode
3 k& a, b6 W* X6 N2 z* E - MOV sp,r0 ; write the stack pointer
X: Z0 L$ T! T/ F0 Y - SUB r0,r0, #FIQ_STACK_SIZE ; give stack space+ w6 e0 L" }; N% P4 x
- ;
- W6 g( E5 Z" F2 f9 o* a - ; Set up the Stack for IRQ mode' y9 M* w9 A0 P9 p1 y% Q5 S
- ;& w0 M1 ^& B; `1 v8 Q1 q. S" a6 r- n7 w
- MSR cpsr_c, #MODE_IRQ|I_F_BIT ; change to IRQ mode I( K% d$ M/ U6 I
- MOV sp,r0 ; write the stack pointer
9 ]' h( H1 F [; ?. U R, J& q k - SUB r0,r0, #IRQ_STACK_SIZE ; give stack space
0 G' `* Y- m p# { - ;
% p; {! s4 q# n8 { - ; Set up the Stack for SVC mode
. N5 A1 J" B& [; z" c - ;. x* v: Z3 b" c7 X. `$ Y$ b6 o& l
- MSR cpsr_c, #MODE_SVC|I_F_BIT ; change to SVC mode
' K2 A6 e7 f* S% O5 J7 F6 N - MOV sp,r0 ; write the stack pointer8 [$ S5 Q6 U; ^( [$ X# o
- SUB r0,r0, #SVC_STACK_SIZE ; give stack space
, K7 t Q6 T' X: Q# u' M7 F! w - ;
, |5 R- P5 D/ v+ R: E; e# q& Z, c - ; Set up the Stack for USer/System mode
. J2 ?; V, V* q ^* P- ~! S7 q - ;
: g5 D( M" [5 {( a" a- t - MSR cpsr_c, #MODE_SYS|I_F_BIT ; change to system mode, U2 f) q& L+ _4 C8 y7 N$ w
- MOV sp,r0 ; write the stack pointer8 _5 X& ?( N: B) y y
- 7 P0 f* \/ U& [3 i! J
- ;
1 z6 T( D" }8 h: a+ v5 L, Z- E - ; Clear the BSS section here
* D: k; E* v, Q - ;
8 d% s6 m' c6 V) N S - Clear_Bss_Section:
5 }7 T4 L) e F4 D9 C9 v+ \$ W - ) }3 I, \7 h) C5 j0 A) H0 R4 K
- LDR r0, _bss_start ; Start address of BSS
% \& P0 b+ c! F7 F* `4 I: q) L - LDR r1, _bss_end ; End address of BSS
8 u5 M7 {+ ?, }; }, p" B* f - SUB r1,r1,#4
% W- m: @- W# R( n - MOV r2, #0
9 L9 B2 d8 G9 t) l$ W6 ] - Loop:: y7 u9 y7 d/ M( r! @& c! S* E
- STR r2, [r0], #4 ; Clear one word in BSS* ?, L' e7 g" p
- CMP r0, r1- W- f. z6 ?( z. P" K
- BLE Loop ; Clear till BSS end" L& b& L9 @- R
5 y3 A$ G/ @2 L( V# M- BL __TI_auto_init ; Call TI auto init
2 k2 t* r( _5 ?9 i - o# W. F1 z( @& `/ a: ^$ a
- ;
. \+ e0 ^$ n8 k# B; {+ w# Z& s% ]; O - ; Enter the start_boot function. The execution still happens in system mode1 d& E3 F9 B0 o4 c
- ;1 I5 u @. Y! N' W' v% n& X
- LDR r10, _start_boot ; Get the address of start_boot" I& k/ D+ I/ }' k
- MOV lr,pc ; Dummy return * Y3 c9 z- G' `$ F; |' P6 S( O
- BX r10 ; Branch to start_boot
g# @/ D; s8 S( L- n - SUB pc, pc, #0x08 ; looping
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. t& X8 m% s1 w, l6 `. J; O- ; MSR cpsr_c, #MODE_SVC|I_F_BIT ; change to SVC mode; \5 z% q2 t0 l, g/ Y
- ; BX lr. n2 d8 y' I$ b, B1 N G
- ;+ n/ K9 |. r! U3 `3 h1 ~
- ; End of the file
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# i, a8 t1 @$ @6 z! a- _stackptr:! M* ?. T( q" M# F6 x- [
- .word __STACK_END, R( K0 F! r3 {
- _bss_start:
) W% [6 F" v- U/ Z - .word bss_start# ]) ]9 a2 C& \4 f
- _bss_end:
, N5 E# Q- X; a# B6 [ - .word bss_end
$ t6 ]9 @9 } R% d( B! Y) ~2 k - _start_boot: ]* g1 `$ G# k" O
- .word start_boot) B1 v# B% s7 f( ?7 ]
- _data_auto_init:
1 C! R: R4 X8 X/ M7 R - .word __TI_auto_init
4 E7 \5 j& E2 L+ j, W - .end
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- / ^$ m' c' E; @1 P& u
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复制代码 8 O, F4 f ^/ X) y% B
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