ZYNQ 双CPU裸机运行例程

vivado 2014.4

特殊情况：总DDR内存大于512MB，且CPU0已经占用了超过512MB，这时按以下步骤CPU1无法启动。

原因：启动入口地址限制。更改方法如下：

打开cpu1_bsp\ps7_cortexa9_1\libsrc\standalone_v4_2\src\boot.S，注释为以下效果即可

#if USE_AMP==1
//	ldr	r3, =0x1ff			/* 512 entries to cover 512MB DDR */
//	ldr	r0, =TblBase			/* MMU Table address in memory */
//	add	r0, r0, #0x800			/* Address of entry in MMU table, for 0x20000000 */
//	ldr	r2, =0x0c02			/* S=b0 TEX=b000 AP=b11, Domain=b0, C=b0, B=b0 */
//mmu_loop:
//	str	r2, [r0]			/* write the entry to MMU table */
//	add	r0, r0, #0x4			/* next entry in the table */
//	add	r2, r2, #0x100000		/* next section */
//	subs	r3, r3, #1
//	bge	mmu_loop			/* loop till 512MB is covered */
#endif

部分所需代码：

#define sev() __asm__("sev")
#define CPU1STARTADR 0xFFFFFFF0 //这个地址是固定的
#define CPU1STARTMEM 0x3D000000 //这个CPU1启动地址是在lscript.ld中设置的

void StartCpu1(void)
{
    #if 1
    fsbl_printf(DEBUG_GENERAL,"FSBL: Write the address of the application for CPU 1 to 0xFFFFFFF0\n\r");
    Xil_Out32(CPU1STARTADR, CPU1STARTMEM);
    dmb(); //waits until write has finished
    fsbl_printf(DEBUG_GENERAL,"FSBL: Execute the SEV instruction to cause CPU 1 to wake up and jump to the application\n\r");
    sev();
    #endif
}

-DUSE_AMP=1

#define sev() __asm__("sev")
#define CPU1STARTADR 0xFFFFFFF0
#define CPU1STARTMEM 0x02000000//此处必须与第5步改的cpu1的ddr地址一致
void StartCpu1(void)
{
    #if 1
    fsbl_printf(DEBUG_GENERAL,"FSBL: Write the address of the application for CPU 1 to 0xFFFFFFF0\n\r");
    Xil_Out32(CPU1STARTADR, CPU1STARTMEM);
    dmb(); //waits until write has finished
    fsbl_printf(DEBUG_GENERAL,"FSBL: Execute the SEV instruction to cause CPU 1 to wake up and jump to the application\n\r");
    sev();
    #endif
}

//app_cpu0.c为以下代码
#include <stdio.h>
#include "platform.h"
#include "xil_printf.h"
#include "sleep.h"
int main()
{
    init_platform();
    while(1)
    {
	print("CPU 0 : Hello World\r\n");
	sleep(2);
    }
    cleanup_platform();
    return 0;
}

//app_cpu1.c为以下代码
#include <stdio.h>
#include "platform.h"
#include "xil_printf.h"
#include "sleep.h"
int main()
{
    init_platform();
    while(1)
    {
	print("CPU 1 : New World\r\n");
	sleep(3);
    }
    cleanup_platform();
    return 0;
}