Untitled

MEMORY {
    HEADER:     start = $3000,  size = $10,     file = %O,  fill = yes;
    ZP:         start = $0000,  size = $100,    type = rw,  define = yes;
    RAM:        start = $200,   size = $600,    type = rw,  define = yes;
    SRAM:       start = $6000,  size = $2000,   type = rw,  define = yes;
    ROM:        start = $8000,  size = $8000,   type = ro,  define = yes,   file = %O;
}

SEGMENTS {
    HEADER:     load = HEADER,  type = wprot;
    CODE:       load = ROM,     type = wprot,   define = yes;
    RODATA:     load = ROM,     type = wprot,   define = yes, align = 256;
    DATA:       load = ROM, run = RAM, type = rw, define = yes;
    BSS:        load = RAM,     type = bss,     define = yes;
    SBSS:       load = SRAM,    type = bss,     define = yes;
    ZEROPAGE:   load = ZP,      type = zp;
}

in the asm file:

    .segment "HEADER"
    .byt "NES",$1A
    .byt NUMPRG, NUMCHR
    .byt MIRROR_FLAGS_MAPPER
    .byt MAPPER_PC10_VS
    .byt 0, 0, 0, 0, 0, 0, 0, 0