AI-on-the-edge-device/code/components/jomjol_helper/himem_memory_check.cpp

// need [env:esp32cam-dev-himem]
//CONFIG_SPIRAM_BANKSWITCH_ENABLE=y
//CONFIG_SPIRAM_BANKSWITCH_RESERVE=4



#include "../../include/defines.h"

#ifdef DEBUG_HIMEM_MEMORY_CHECK

#include "himem_memory_check.h"

//source adapted from : https://github.com/espressif/esp-idf/blob/master/examples/system/himem/main/himem_example_main.c


//Fill memory with pseudo-random data generated from the given seed.
//Fills the memory in 32-bit words for speed.
static void fill_mem_seed(int seed, void *mem, int len)
{
    uint32_t *p = (uint32_t *)mem;
    unsigned int rseed = seed ^ 0xa5a5a5a5;
    for (int i = 0; i < len / 4; i++) {
        *p++ = rand_r(&rseed);
    }
}

//Check the memory filled by fill_mem_seed. Returns true if the data matches the data
//that fill_mem_seed wrote (when given the same seed).
//Returns true if there's a match, false when the region differs from what should be there.
static bool check_mem_seed(int seed, void *mem, int len, int phys_addr)
{
    uint32_t *p = (uint32_t *)mem;
    unsigned int rseed = seed ^ 0xa5a5a5a5;
    for (int i = 0; i < len / 4; i++) {
        uint32_t ex = rand_r(&rseed);
        if (ex != *p) {
            //printf("check_mem_seed: %x has 0x%08"PRIx32" expected 0x%08"PRIx32"\n", phys_addr+((char*)p-(char*)mem), *p, ex);
            return false;
        }
        p++;
    }
    return true;
}

//Allocate a himem region, fill it with data, check it and release it.
static bool test_region(int check_size, int seed)
{
    esp_himem_handle_t mh; //Handle for the address space we're using
    esp_himem_rangehandle_t rh; //Handle for the actual RAM.
    bool ret = true;

    //Allocate the memory we're going to check.
    ESP_ERROR_CHECK(esp_himem_alloc(check_size, &mh));
    //Allocate a block of address range
    ESP_ERROR_CHECK(esp_himem_alloc_map_range(ESP_HIMEM_BLKSZ, &rh));
    for (int i = 0; i < check_size; i += ESP_HIMEM_BLKSZ) {
        uint32_t *ptr = NULL;
        //Map in block, write pseudo-random data, unmap block.
        ESP_ERROR_CHECK(esp_himem_map(mh, rh, i, 0, ESP_HIMEM_BLKSZ, 0, (void**)&ptr));
        fill_mem_seed(i ^ seed, ptr, ESP_HIMEM_BLKSZ); //
        ESP_ERROR_CHECK(esp_himem_unmap(rh, ptr, ESP_HIMEM_BLKSZ));
    }
    vTaskDelay(5); //give the OS some time to do things so the task watchdog doesn't bark
    for (int i = 0; i < check_size; i += ESP_HIMEM_BLKSZ) {
        uint32_t *ptr;
        //Map in block, check against earlier written pseudo-random data, unmap block.
        ESP_ERROR_CHECK(esp_himem_map(mh, rh, i, 0, ESP_HIMEM_BLKSZ, 0, (void**)&ptr));
        if (!check_mem_seed(i ^ seed, ptr, ESP_HIMEM_BLKSZ, i)) {
            //printf("Error in block %d\n", i / ESP_HIMEM_BLKSZ);
            ret = false;
        }
        ESP_ERROR_CHECK(esp_himem_unmap(rh, ptr, ESP_HIMEM_BLKSZ));
        if (!ret) break; //don't check rest of blocks if error occurred
    }
    //Okay, all done!
    ESP_ERROR_CHECK(esp_himem_free(mh));
    ESP_ERROR_CHECK(esp_himem_free_map_range(rh));
    return ret;
}


std::string himem_memory_check()
{
    size_t memcnt=esp_himem_get_phys_size();
    size_t memfree=esp_himem_get_free_size();

	std::string espInfoResultStr = "";
    char aMsgBuf[40];

	espInfoResultStr += "Running HIMEM memory check";

	sprintf(aMsgBuf,"Himem has %dKiB of memory", (int)memcnt/1024);
	espInfoResultStr += std::string(aMsgBuf);

	sprintf(aMsgBuf,"%dKiB of which is free", (int)memfree/1024);
	espInfoResultStr += std::string(aMsgBuf);

	espInfoResultStr += "\n please wait ....\n";

	//running memory checks
	//assert(test_region(memfree, 0xaaaa));

	if(test_region(memfree, 0xaaaa)) {
		espInfoResultStr += "Himem check Failed!\n";
	} else {
		espInfoResultStr += "Himem check Done!\n";
	}

	return espInfoResultStr; 

}


#endif // DEBUG_HIMEM_MEMORY_CHECK