sw/device/tests/kelvin/kelvin_checksum.c

// Copyright 2023 Google LLC.
// Licensed under the Apache License, Version 2.0, see LICENSE for details.
// SPDX-License-Identifier: Apache-2.0
//
// A kelvin program that computes the checksum from a range of the memory.

#include <stddef.h>
#include <stdint.h>

const uint32_t kInput = 0x300000;
const uint32_t kOutput = 0x380000;
const int kImageWords = 320 * 240 / sizeof(uint32_t);

int main(int argc, char *argv[]) {
  const uint32_t *input = (const uint32_t *)kInput;
  uint32_t *output = (uint32_t *)kOutput;

  uint32_t checksum = 0;

  for (int i = 0; i < kImageWords; ++i) {
    checksum += input[i];
  }

  *output = checksum;

  // Flush the output value to the address 0x380000.
  asm volatile("lw a5, %0" : : "m"(output));
  asm volatile(".word 0x26078077");  // flushat a5
  return 0;
}