#include <memory.h>
#include <string.h>
#include <uart.h>

#define MAX_PROBE_SIZE (256 * 1024 * 1024) // Probe up to 256 MiB max
#define PROBE_STEP     0x1000              // Probe every 4 KiB page

size_t probe_memory(void) {
    volatile u32 *addr;
    u32           test_pattern = 0xA5A5A5A5;
    size_t        detected = 0;

    for (size_t offset = 4096 * 16; offset < MAX_PROBE_SIZE;
         offset += PROBE_STEP) {
        addr = (volatile u32 *)(KERNBASE + offset);

        u32 old = *addr;
        *addr = test_pattern;

        if (*addr != test_pattern) {
            break; // Memory not readable/writable here, stop probing
        }

        *addr = old; // restore original data
        detected = offset + PROBE_STEP;
    }

    return detected;
}