fpga to hps bridge - stratix 10

Hi @JingyangTeh_Altera

Thank you for the help! I have been able to get the h2f_lw bridge working! My real issue is using the f2h bridge.

I have updated my Qsys design based off of this reference I found from Cornell University:

https://people.ece.cornell.edu/land/courses/ece5760/DE1_SOC/HPS_peripherials/FPGA_addr_index.html

Specifically

https://people.ece.cornell.edu/land/courses/ece5760/DE1_SOC/HPS_FPGA/FIFO/FIFO_write_read/Qsys.PNG

I will attach my design as well.

And here are my address maps

After generating the HDL and adding in a simple function into the verilog file

"

always @(posedge clk_100_out_clk_clk or posedge rst_controller_reset_out_reset) begin
if (rst_controller_reset_out_reset) begin
internal_reg <= 0;
end else begin
// Perform arithmetic (multiply by 10)
internal_reg <= qsys_top_fifo_hps_to_fpga_out_csr_writedata * 10;
end
end

assign qsys_top_fifo_fpga_to_hps_in_csr_writedata = internal_reg;

"

I have developed C code for a server and a client socket. Here are some important parts

" Server.c

#define FPGA_BASE_ADDRESS 0xF9000000 // BASE ADDRESS For MASTER
#define FPGA_SPAN 0x00200000 // 2 MB Span

#define INPUT_REG_OFFSET 0x20 // BASE ADDRESS for input reg
#define OUTPUT_REG_OFFSET 0x00 // BASE ADDRESS for output reg

...

// Map the FPGA AXI slave interface to the virtual address space
void *virtual_base = mmap(NULL, FPGA_SPAN, PROT_READ | PROT_WRITE, MAP_SHARED, fd, FPGA_BASE_ADDRESS);
if (read == MAP_FAILED) {
perror("Failed to map memory");
close(fd);
return -1;
}

// Get the virtual address of the input and output registers
volatile uint32_t *input_reg = (volatile uint32_t *)(virtual_base + INPUT_REG_OFFSET);
volatile uint32_t *output_reg = (volatile uint32_t *)(virtual_base + OUTPUT_REG_OFFSET);

...

// Receive data from the client
int valread = recv(new_socket, buffer, sizeof(buffer), 0);
if (valread <= 0) {
perror("recv failed");
break;
}

if (strcmp(buffer, "Exit\n") == 0) {
// Exit the arithmetic
printf("Exiting...\n");
break;
} else {
sscanf(buffer, "%ls", &value);
// valid input

printf("Client Input: %ls\n", &value);

*input_reg = value;

// Wait for the FPGA to perform the arithmetic
usleep(1000);

// Read the result from the FPGA
result = *output_reg;

"

And for the client

" client.c

...

// Receive the server's response
memset(buffer, 0, sizeof(buffer));
rec = read(sock, &rec, sizeof(rec));
printf("Server response: %d\n", rec);
rec = 0;
}

"

Here is the output.

Client Output:

Server Output:

The server can see the correct input from the client, however the result is a constant "2899692286", which is curious because this is the output from the command

root@stratix10:~# cat /sys/bus/platform/devices/f9000000.SYSID_QSYS/sysid/id

found in https://www.rocketboards.org/foswiki/Documentation/HOWTOCreateADevicetreeForStratix10SoC

and the client collects a constant "4" which is also strange because I would expect that it would return "2899692286".

This leads me to believe that the fpga to hps bridge is not configured correctly, or I have put the wrong address for OUTPUT_REG in my c code, which is why I have bolded it. I am confident though that the h2f_lw bridge is working.

The Output should just multiply the input by 10, not this system ID.

Sorry about the overflow of information.

Again, any help to understand the f2h bridge would be very helpful.

Thanks,

James