usbloadergx/source/patches/dolpatcher.c

#include <string.h>
#include <gctypes.h>

bool PatchDOL( u8 * Address, int Size, const u8 * SearchPattern, int SearchSize, const u8 * PatchData, int PatchSize )
{
    u8 * Addr = Address;
    u8 * Addr_end = Address + Size;

    while ( Addr <= Addr_end - SearchSize )
    {
        if ( memcmp( Addr, SearchPattern, SearchSize ) == 0 )
        {
            memcpy( Addr, PatchData, PatchSize );
            return true;
        }
        Addr += 4;
    }
    return false;
}