将程序从Flash搬运到RAM中运行总结解析

1、F2812程序从Flash搬到RAM中运行【非本人原创】第一步：/ Fun cti ons that will be run from RAM n eed to be assig ned to/ a differe nt sect ion. This secti on will the n be mapped using/ the lin ker cmd file.#pragma CODE_SECTION(EPwm1_timer_isr, ramfu ncs;#pragma CODE_SECTION(EPwm2_timer_isr, ramfu ncs;MAIN(/ These are def

2、ined by the linker (see F2808.cm在 CMD 里面定义的变量 externUi nt16 Ramfu ncsLoadStart;exter n Uin t16 Ramfun csLoadE nd;exter n Ui nt16 Ramfu ncsRu nStart;User specific code, en able in terrupts:/ Copy time critical code and Flash setup code to RAM/ This in cludes the followi ng ISR fun cti ons: EPwm1_time

3、r_isr(, EPwm2_timer_isr(/ EPwm3_timer_isr and and In itFlash(;/ The Ramfun csLoadStart, Ramfun csLoadE nd, and Ramfun csR un Start / symbols are created by the lin ker. Refer to the F2808.cmd file. MemCopy(&Ramfu ncsLoadStart, &Ramf un csLoadE nd, & Ramfu ncsR un Start;/ Call Flash Initialization to

4、 setup flash waitstates/ This function must reside in RAMInitFlash(;/FLASH初始化的函数不能在FLASH里面运行，必须拷到别的 内存 空间里运行才能对FLASH进行初始化。第二步:将要从FLASH里面加载到RAM的函数定义到ramfuncs/ Fun cti ons that will be run from RAM n eed to be assig ned to/ a differe nt sect ion. This secti on will the n be mapped to a load and / run

5、address using the lin ker cmd file.#pragma CODE_SECTION(I ni tFlash, ramfu ncs;第三步：CMD文件：MEMORYPAGE 0:PRAML0 : origin = 0x008000, le ngth = 0x000800 FLASHA : origin = 0x3F6000, len gth = 0x001F80 SECTIONSramfu ncs : LOAD = FLASHA,RUN = PRAML0,LOAD_START(_Ramfu ncsLoadStart,LOAD_END(_Ramfu ncsLoadE n

6、d,RUN_START(_Ramfu ncsRu nStart,PAGE = 0总结:在MAP文件里:从FLASH加载到RAM运行的程序会有二个实际的存储 空间，一个在FLASH里面，另一个在 RAM里。ramfuncs : LOAD = FLASHA,/指定 了要加载程序存储在FLASH里面的地址段。RUN = PRAML0,/指令了在RAM里运行程序的RAM空间段。 LOAD_START(_Ramfu ncsLoadStart,/_Ramfu ncsLoadSt art 指向了 FLASH 里的程序 起始地址，LOAD_END(_RamfuncsLoadEnd,/_RamfuncsLoad

7、End指向了 FLASH 里的程 序结束地址ramfuncs功能指令了存在于FLASHA里面的一个连续代码段空间，并且为这段 代码空间分配了一个在RAM里运行的指针(RamfuncsRunStart，应用时我们道先要 将加载到RAM里运行的程序通过#pragma CODE_SECTION指令分配到这一个连 续的代码空间，然后通过MEMCPY指令存在于FLASH里的代码复制到能足够容 纳的RAM空间里MAP文件里的表现：SECTION ALLOCATION MAPramfu ncs 0 003f65d6 0000004d RUN ADDR = 00008000003f65d6 0000001b

8、DSP2802x_SysCtrl.obj (ramfu ncs003f65f1 00000004 DSP2802x_usDelay.obj (ramfu ncs003f65f5 0000002e Example_2802xFlash.obj (ramfu ncs.ci nit 0 003f6623 00000019003f6623 0000000e rts2800_ml.lib : exit.obj (.ci nit003f6631 0000000a :o ck.obj (.ci nit003f663b 00000001 -HOLE- fill = 0GLOBAL SYMBOLS: SORTED ALPHABETICALLY BY Name003f6623 _Ramfu ncsLoadE nd003f65d6 _Ramfu ncsLoadStart00008000 _Ramfu ncsRu nStartGLOBAL SYMBOLS: SORTED BY Symbol Address00008000 _Ramfu ncsRu nStart0000801b _DSP28x_usDelay三个从FLASH里加载RAM里运行的程序0000801f _EPwm1_timer_isr00008035 _EPwm2_timer_isr003f65d6 RamfuncsL