In a bare-metal/standalone environment, Xilinx provides standalone board support package (BSP), drivers, and libraries for applications to use to reduce development effort. As described in Host Programming on Linux, the top-level application for bare-metal systems must also integrate and manage the AI Engine graph and PL kernels.
The following is an example top-level application (main.cpp) for a bare-metal system:
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <unistd.h>
#include "platform.h"
#include "xparameters.h"
#include "xil_io.h"
#include "xil_cache.h"
#include "input.h"
#include "golden.h"
...
void InitData(int32_t** out, int size)
{
int i;
*out = (int32_t*)malloc(sizeof(int32_t) * size);
if(!out) {
printf("Allocation of memory failed \n");
exit(-1);
}
for(i = 0; i < size; i++) {
(*out)[i] = 0xABCDEF00;
}
}
int RunTest(uint64_t mm2s_base, uint64_t s2mm_base, int32_t* in, int32_t* golden,
int32_t* out, int input_size, int output_size)
{
int i;
int errCount = 0;
uint64_t memAddr = (uint64_t)in;
uint64_t mem_outAddr = (uint64_t)out;
printf("Starting test w/ cu\n");
Xil_Out32(mm2s_base + MEM_OFFSET, (uint32_t) memAddr);
Xil_Out32(mm2s_base + MEM_OFFSET + 4, 0);
Xil_Out32(s2mm_base + MEM_OFFSET, (uint32_t) mem_outAddr);
Xil_Out32(s2mm_base + MEM_OFFSET + 4, 0);
Xil_Out32(mm2s_base + SIZE_OFFSET, input_size);
Xil_Out32(s2mm_base + SIZE_OFFSET, output_size);
Xil_Out32(mm2s_base + CTRL_OFFSET, 1);
Xil_Out32(s2mm_base + CTRL_OFFSET, 1);
printf("GRAPH INIT\n");
clipgraph.init();
printf("GRAPH RUN\n");
clipgraph.run();
while(1) {
uint32_t v = Xil_In32(s2mm_base + CTRL_OFFSET);
if(v & 6) {
break;
}
}
printf("PLIO IP DONE!\n");
for(i = 0; i < output_size; i++) {
if((((int32_t*)out)[i] != ((int32_t*)golden)[i]) ) {
printf("Error found in sample %d != to the golden %d\n", i+1, ((int32_t*)out)[i], ((int32_t*)golden)[i]);
errCount++;
}
else
printf("%d\n ",((int32_t*)out)[i]);
}
printf("Ending test w/ cu\n");
return errCount;
}
int main()
{
int i;
int32_t* out;
int errCount;
Xil_DCacheDisable();
init_platform();
sleep(1);
printf("Beginning test\n");
InitData(&out, OUTPUT_SIZE);
errCount = RunTest(MM2S_BASE, S2MM_BASE, (int32_t*)cint16input, int32golden, out, INPUT_SIZE, OUTPUT_SIZE);
if(errCount == 0)
printf("Test passed. \n");
else
printf("Test failed! Error count: %d \n",errCount);
cleanup_platform();
return errCount;
}
The following are the steps in the code example:
- The
main()
function initializes the platform, data, runs the test, verifies the return code, and return the error code. -
InitData()
allocatessize
of memory space and initializes successfully allocated memory space to known data. -
RunTest()
passes necessary data to the kernel to process and return a result. -
clipgraph.init()
initializes the tiles that kernels will be run on. -
clipgraph.run()
starts kernels running on associated tiles.
The preceding code example references xparameters.h which is automatically generated from the bare-metal BSP. The application needs to ensure the bare-metal BSP is properly generated so that the memory mapped addresses for all drivers are correctly assigned.
xil_io.h contains general driver I/O APIs. This is the preferred method for accessing drivers.