/* override entry point */ ENTRY(ESP32Reset) /* reserved for ICACHE */ RESERVE_ICACHE = 0x8000; VECTORS_SIZE = 0x400; /* Specify main memory areas 40370000 <- IRAM/Icache -> 40378000 <- D/IRAM (I) -> 403E0000 3FC88000 <- D/IRAM (D) -> 3FCF0000 <- DRAM/DCache -> 3FD00000 Startup code uses the IRAM from 0x403B9000 to 0x403E0000, which is not available for static memory, but can only be used after app starts. D cache use the memory from high address, so when it's configured to 16K/32K, the region 0x3FCF0000 ~ (3FD00000 - DATA_CACHE_SIZE) should be available. This region is not used as static memory, leaving to the heap. */ MEMORY { vectors_seg ( RX ) : ORIGIN = 0x40370000 + RESERVE_ICACHE, len = VECTORS_SIZE iram_seg ( RX ) : ORIGIN = 0x40370000 + RESERVE_ICACHE + VECTORS_SIZE, len = 328k - VECTORS_SIZE - RESERVE_ICACHE dram_seg ( RW ) : ORIGIN = 0x3FC88000 , len = 345856 /* external flash The 0x20 offset is a convenience for the app binary image generation. Flash cache has 64KB pages. The .bin file which is flashed to the chip has a 0x18 byte file header, and each segment has a 0x08 byte segment header. Setting this offset makes it simple to meet the flash cache MMU's constraint that (paddr % 64KB == vaddr % 64KB).) */ irom_seg ( RX ) : ORIGIN = 0x42000020, len = 4M - 0x20 drom_seg ( R ) : ORIGIN = 0x3C000020, len = 4M - 0x20 /* RTC fast memory (executable). Persists over deep sleep. Only for core 0 (PRO_CPU) */ rtc_fast_seg(RWX) : ORIGIN = 0x600fe000, len = 8k /* RTC slow memory (data accessible). Persists over deep sleep. */ rtc_slow_seg(RW) : ORIGIN = 0x50000000, len = 8k }