底层提供只读内存

底的英语翻译：

a copy kept as a record; base; bottom; end; fundus; the truth of a matter
【医】 base; basement; bases; basi-; basio-; basis; batho-; bathy-; fimdi
floor; fundus; pavimentum; solum

层的英语翻译：

layer; region; stage; story; stratum; tier
【计】 layer
【医】 coat; lamella; lamellae; lamina; laminae; layer; strata; stratum

提供的英语翻译：

offer; provide; afford; furnish; lend; supply
【经】 offer; render

只读内存的英语翻译：

RAM
【计】 read-only memory