DSP中的CMD文件是链接命令文件(Linker Command File),以.cmd为后缀。
在分析cmd文件之前,必需先了解
(1)DSP具体芯片的内存映射(Memory Map)
(2)知道点链接的知识,知道C程序中段的概念
(3)知道RAM,Flash等存储模块的区别
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1. coff目标文件
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coff是一种流行的二进制可执行文件格式,在CCS v5中扩展名为.out,可以直接
下载到芯片中。可执行文件包括段头、可执行代码、初始化数据、可重定位信息
和符号表字符串表等信息。
编译器处理段的过程为:
(1)把每个源文件都编译成独立目标文件(.obj),每个目标文件都有自己的段
(2)链接器将目标文件中相同段名的部分连接在一起,生成最终的coff可执行文件
CCS v5中的Compile Files完成功能(1),Build完成功能(2)。
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2. TMS320C6713内存映射
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3. 自定义代码段和数据段
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// 将symbol分配到section name指示的数据段
#pragma DATA_SECTION(symbol, "section name");
// 将symbol分配到section name指示的代码段
#pragma CODE_SECTION(symbol, "section name");
常常结合结构体定义symbol,如下,
volatile struct Symbol symbol; // Symbol预先定义好的描述特定外设的结构
比如,对于C6713中的Timer0外设,做如下定义,
- struct Timer0 {
- ...
- }
- #pragma DATA_SECTION(C6713_Timer0, "C6713_Timer0_cmd");
- volatile struct Timer0 C6713_Timer0;
struct Timer0 { ...}#pragma DATA_SECTION(C6713_Timer0, "C6713_Timer0_cmd");volatile struct Timer0 C6713_Timer0;
"C6713_Timer0_cmd"将在cmd文件中分配空间。
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4. cmd文件
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cmd文件主要用于完成链接的功能,因此可以在cmd文件中使用链接命令,比如:
-stack 0x200 设置栈大小为0x200字节
-heap 0x200 设置堆大小为0x200字节
-l rst67xx.lib 链接rst67xx.lib库
除了链接命令外,cmd 文件还包括MEMORY和SECTOINS两部分,分别用于存储区的划分和段的分配。
MEMORY划分的格式为:
- L2SRAM : o = 00000000h l = 00030000h /* L2 SRAM 192K */
L2SRAM : o = 00000000h l = 00030000h /* L2 SRAM 192K */o表示起始地址,l表示存储区长度(以字节为单位)
一个简单的例子(TMS320C6713为例,不同芯片不同),外设只添加了Timer0:
- MEMORY
- {
- L2SRAM : o = 00000000h l = 00030000h /* L2 SRAM 192K */
- L2CACHE : o = 00030000h l = 00010000h /* L2 Cache 64 K */
-
-
- /* Peripheral */
- CPU_TIMER0 : o = 01940000h l = 00040000 /* Timer0 */
-
-
- EXTERNAL : o = 80000000h l = 80010000h
- }
-
-
- SECTIONS
- {
- /* Allocate program areas */
- .text > L2SRAM /* code segment */
- .cinit > L2SRAM /* init segment */
-
-
- /* Allocate data areas */
- .stack > L2SRAM
- .far > L2SRAM
- .switch > L2SRAM /* C switch table */
- .tables > L2SRAM
- .data > L2SRAM /* data segment */
- .bss > L2SRAM /* data that haven't init */
- .sysmem > L2SRAM
- .const > L2SRAM /* string, const ... */
- .cio > L2SRAM
-
-
- .buffers > EXTERNAL
-
-
- C6713_Timer0_cmd > CPU_TIMER0 /* Timer 0 */
- }
MEMORY{ L2SRAM : o = 00000000h l = 00030000h /* L2 SRAM 192K */ L2CACHE : o = 00030000h l = 00010000h /* L2 Cache 64 K */ /* Peripheral */ CPU_TIMER0 : o = 01940000h l = 00040000 /* Timer0 */ EXTERNAL : o = 80000000h l = 80010000h}SECTIONS{ /* Allocate program areas */ .text > L2SRAM /* code segment */ .cinit > L2SRAM /* init segment */ /* Allocate data areas */ .stack > L2SRAM .far > L2SRAM .switch > L2SRAM /* C switch table */ .tables > L2SRAM .data > L2SRAM /* data segment */ .bss > L2SRAM /* data that haven't init */ .sysmem > L2SRAM .const > L2SRAM /* string, const ... */ .cio > L2SRAM .buffers > EXTERNAL C6713_Timer0_cmd > CPU_TIMER0 /* Timer 0 */}
cmd文件包括2部分 —— MEMORY与SECTIONS
MEMORY完成地址空间的划分;
SECTIONS完成地址空间的分配到具体用途(除了程序中通用段之外还可以有自定义段)。
NOTES: 平时开发时都是将程序下载到RAM空间,当要发布时需要下载到Flash空间,
此处为SRAM的cmd文件,Flash的cmd文件有所不同。
下面是TI公司DSK的cmd,可以直接参考,
- /****************************************************************************/
- /* C6713.cmd */
- /* Copyright (c) 2010 Texas Instruments Incorporated */
- /* */
- /* Description: This file is a sample linker command file that can be */
- /* used for linking programs built with the C compiler and */
- /* running the resulting .out file on an TMS320C6713 */
- /* device. Use it as a guideline. You will want to */
- /* change the memory layout to match your specific C6xxx */
- /* target system. You may want to change the allocation */
- /* scheme according to the size of your program. */
- /* */
- /****************************************************************************/
-
- -stack 0x2000
- -heap 0x8000
-
- MEMORY
- {
- IRAM o = 0x00000000 l = 0x00030000 /* 192kB - Internal RAM */
- L2RAM o = 0x00030000 l = 0x00010000 /* 64kB - Internal RAM/CACHE */
- EMIFCE0 o = 0x80000000 l = 0x10000000 /* SDRAM in 6713 DSK */
- EMIFCE1 o = 0x90000000 l = 0x10000000 /* Flash/CPLD in 6713 DSK */
- EMIFCE2 o = 0xA0000000 l = 0x10000000 /* Daughterboard in 6713 DSK */
- EMIFCE3 o = 0xB0000000 l = 0x10000000 /* Daughterboard in 6713 DSK */
- }
-
- SECTIONS
- {
- .text > IRAM
- .stack > IRAM
- .bss > IRAM
- .cio > IRAM
- .const > IRAM
- .data > IRAM
- .switch > IRAM
- .sysmem > IRAM
- .far > IRAM
- .args > IRAM
- .ppinfo > IRAM
- .ppdata > IRAM
-
- /* COFF sections */
- .pinit > IRAM
- .cinit > IRAM
-
- /* EABI sections */
- .binit > IRAM
- .init_array > IRAM
- .neardata > IRAM
- .fardata > IRAM
- .rodata > IRAM
- .c6xabi.exidx > IRAM
- .c6xabi.extab > IRAM
- }
/****************************************************************************//* C6713.cmd *//* Copyright (c) 2010 Texas Instruments Incorporated *//* *//* Description: This file is a sample linker command file that can be *//* used for linking programs built with the C compiler and *//* running the resulting .out file on an TMS320C6713 *//* device. Use it as a guideline. You will want to *//* change the memory layout to match your specific C6xxx *//* target system. You may want to change the allocation *//* scheme according to the size of your program. *//* *//****************************************************************************/-stack 0x2000-heap 0x8000MEMORY{ IRAM o = 0x00000000 l = 0x00030000 /* 192kB - Internal RAM */ L2RAM o = 0x00030000 l = 0x00010000 /* 64kB - Internal RAM/CACHE */ EMIFCE0 o = 0x80000000 l = 0x10000000 /* SDRAM in 6713 DSK */ EMIFCE1 o = 0x90000000 l = 0x10000000 /* Flash/CPLD in 6713 DSK */ EMIFCE2 o = 0xA0000000 l = 0x10000000 /* Daughterboard in 6713 DSK */ EMIFCE3 o = 0xB0000000 l = 0x10000000 /* Daughterboard in 6713 DSK */}SECTIONS{ .text > IRAM .stack > IRAM .bss > IRAM .cio > IRAM .const > IRAM .data > IRAM .switch > IRAM .sysmem > IRAM .far > IRAM .args > IRAM .ppinfo > IRAM .ppdata > IRAM /* COFF sections */ .pinit > IRAM .cinit > IRAM /* EABI sections */ .binit > IRAM .init_array > IRAM .neardata > IRAM .fardata > IRAM .rodata > IRAM .c6xabi.exidx > IRAM .c6xabi.extab > IRAM}
下面再给出一个TMS320F2818的完整cmd文件例子,与6713有所不同,比如16进制格式
表示,MEMORY和SECTIONS书写等。
- MEMORY
- {
- PAGE 0 :
- PRAMH0 : origin = 0x3f8000, length = 0x001000
-
- PAGE 1 :
- /* SARAM */
- RAMM0 : origin = 0x000000, length = 0x000400
- RAMM1 : origin = 0x000400, length = 0x000400
-
-
- /* Peripheral Frame 0: */
- DEV_EMU : origin = 0x000880, length = 0x000180
- FLASH_REGS : origin = 0x000A80, length = 0x000060
- CSM : origin = 0x000AE0, length = 0x000010
- XINTF : origin = 0x000B20, length = 0x000020
- CPU_TIMER0 : origin = 0x000C00, length = 0x000008
- CPU_TIMER1 : origin = 0x000C08, length = 0x000008
- CPU_TIMER2 : origin = 0x000C10, length = 0x000008
- PIE_CTRL : origin = 0x000CE0, length = 0x000020
- PIE_VECT : origin = 0x000D00, length = 0x000100
-
-
- /* Peripheral Frame 1: */
- ECAN_A : origin = 0x006000, length = 0x000100
- ECAN_AMBOX : origin = 0x006100, length = 0x000100
-
-
- /* Peripheral Frame 2: */
- SYSTEM : origin = 0x007010, length = 0x000020
- SPI_A : origin = 0x007040, length = 0x000010
- SCI_A : origin = 0x007050, length = 0x000010
- XINTRUPT : origin = 0x007070, length = 0x000010
- GPIOMUX : origin = 0x0070C0, length = 0x000020
- GPIODAT : origin = 0x0070E0, length = 0x000020
- ADC : origin = 0x007100, length = 0x000020
- EV_A : origin = 0x007400, length = 0x000040
- EV_B : origin = 0x007500, length = 0x000040
- SPI_B : origin = 0x007740, length = 0x000010
- SCI_B : origin = 0x007750, length = 0x000010
- MCBSP_A : origin = 0x007800, length = 0x000040
-
-
- /* CSM Password Locations */
- CSM_PWL : origin = 0x3F7FF8, length = 0x000008
-
-
- /* SARAM */
- DRAMH0 : origin = 0x3f9000, length = 0x001000
- }
-
- SECTIONS
- {
- /* Allocate program areas: */
- .reset : > PRAMH0, PAGE = 0
- .text : > PRAMH0, PAGE = 0
- .cinit : > PRAMH0, PAGE = 0
-
-
- /* Allocate data areas: */
- .stack : > RAMM1, PAGE = 1
- .bss : > DRAMH0, PAGE = 1
- .ebss : > DRAMH0, PAGE = 1
- .const : > DRAMH0, PAGE = 1
- .econst : > DRAMH0, PAGE = 1
- .sysmem : > DRAMH0, PAGE = 1
-
- /* Allocate Peripheral Frame 0 Register Structures: */
- DevEmuRegsFile : > DEV_EMU, PAGE = 1
- FlashRegsFile : > FLASH_REGS, PAGE = 1
- CsmRegsFile : > CSM, PAGE = 1
- XintfRegsFile : > XINTF, PAGE = 1
- CpuTimer0RegsFile : > CPU_TIMER0, PAGE = 1
- CpuTimer1RegsFile : > CPU_TIMER1, PAGE = 1
- CpuTimer2RegsFile : > CPU_TIMER2, PAGE = 1
- PieCtrlRegsFile : > PIE_CTRL, PAGE = 1
- PieVectTable : > PIE_VECT, PAGE = 1
-
-
- /* Allocate Peripheral Frame 2 Register Structures: */
- ECanaRegsFile : > ECAN_A, PAGE = 1
- ECanaMboxesFile : > ECAN_AMBOX PAGE = 1
-
-
- /* Allocate Peripheral Frame 1 Register Structures: */
- SysCtrlRegsFile : > SYSTEM, PAGE = 1
- SpiaRegsFile : > SPI_A, PAGE = 1
- SciaRegsFile : > SCI_A, PAGE = 1
- XIntruptRegsFile : > XINTRUPT, PAGE = 1
- GpioMuxRegsFile : > GPIOMUX, PAGE = 1
- GpioDataRegsFile : > GPIODAT PAGE = 1
- AdcRegsFile : > ADC, PAGE = 1
- EvaRegsFile : > EV_A, PAGE = 1
- EvbRegsFile : > EV_B, PAGE = 1
- ScibRegsFile : > SCI_B, PAGE = 1
- McbspaRegsFile : > MCBSP_A, PAGE = 1
-
-
- /* CSM Password Locations */
- CsmPwlFile : > CSM_PWL, PAGE = 1
- }
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