qemu/hw/esp.h

/* esp.c */
#define ESP_MAX_DEVS 7
typedef void (*espdma_memory_read_write)(void *opaque, uint8_t *buf, int len);
void esp_init(target_phys_addr_t espaddr, int it_shift,
              espdma_memory_read_write dma_memory_read,
              espdma_memory_read_write dma_memory_write,
              void *dma_opaque, qemu_irq irq, qemu_irq *reset);