Xilinx SDK BSP中对CPU_ID的使用

创建Xilinx SDK BSP时，要指定在哪个core上运行，这个选项对源码的影响如下：

xparameters.h里面的宏定义不同：

/* Definition for CPU ID */
#define XPAR_CPU_ID 1

xscugic_hw.c里面

int XScuGic_DeviceInitialize(u32 DeviceId)
{
	XScuGic_Config *Config;
	u8 Cpu_Id = XPAR_CPU_ID + 1;

	Config = &XScuGic_ConfigTable[(u32 )DeviceId];

	DistInit(Config, Cpu_Id);

	CPUInit(Config);

	return XST_SUCCESS;
}

xscugic.c里面

int  XScuGic_CfgInitialize(XScuGic *InstancePtr,
				XScuGic_Config *ConfigPtr,
				u32 EffectiveAddr)
{
	u32 Int_Id;
	u8 Cpu_Id = XPAR_CPU_ID + 1;

	Xil_AssertNonvoid(InstancePtr != NULL);
	Xil_AssertNonvoid(ConfigPtr != NULL);

	/*
 	 * Set some default values
	 */
	InstancePtr->Config->CpuBaseAddress = EffectiveAddr;
	InstancePtr->IsReady = 0;
	InstancePtr->Config = ConfigPtr;


	for (Int_Id = 0; Int_Id<XSCUGIC_MAX_NUM_INTR_INPUTS;Int_Id++) {
		/*
		 * Initalize the handler to point to a stub to handle an
		 * interrupt which has not been connected to a handler. Only
		 * initialize it if the handler is 0 which means it was not
		 * initialized statically by the tools/user. Set the callback
		 * reference to this instance so that unhandled interrupts
		 * can be tracked.
		 */
		if ((InstancePtr->Config->HandlerTable[Int_Id].Handler == 0)) {
			InstancePtr->Config->HandlerTable[Int_Id].Handler =
								StubHandler;
		}
		InstancePtr->Config->HandlerTable[Int_Id].CallBackRef =
								InstancePtr;
	}

	DistInit(InstancePtr, Cpu_Id);
	CPUInit(InstancePtr);

	InstancePtr->IsReady = XIL_COMPONENT_IS_READY;

	return XST_SUCCESS;
}

boot.S里面

/* this initializes the various processor modes */

_prestart:
_boot:

#if XPAR_CPU_ID==0
/* only allow cpu0 through */
	mrc	p15,0,r1,c0,c0,5
	and	r1, r1, #0xf
	cmp	r1, #0
	beq	OKToRun
EndlessLoop0:
	wfe
	b	EndlessLoop0

#elif XPAR_CPU_ID==1
/* only allow cpu1 through */
	mrc	p15,0,r1,c0,c0,5
	and	r1, r1, #0xf
	cmp	r1, #1
	beq	OKToRun
EndlessLoop1:
	wfe
	b	EndlessLoop1
#endif

OKToRun:
	mrc     p15, 0, r0, c0, c0, 0		/* Get the revision */
	and     r5, r0, #0x00f00000 
	and     r6, r0, #0x0000000f
	orr     r6, r6, r5, lsr #20-4

从上面的汇编来看，如果实际加测到的CPU_ID和配置的CPU_ID如果不同，BSP将无法启动。