crt0.S

/* Move section to .init that is allocatable and executable. */
.section .init, "ax"
.align 2
.global _start

_start:
        .cfi_startproc
        .cfi_undefined ra

        # _setup_mtrap if interrupt is not enabled
        #csrr t0, mstatus
        #beqz t0, _setup_mtrap

        .option push
        .option norelax

        la gp, __global_pointer$
        .option pop

        la sp, __stack_top
        add s0, sp, zero

        # a0 contains the hartid
        # a1 contains a pointer to the machine description (FDT)
        jal initialize_hart
        jal _setup_mtrap

        jal zero, main
        .cfi_endproc
        .end

fdt.c

struct fdt_node *
scan_node(uint32_t *dt_struct)
{
	struct device _dv;
	int i;
	int len = sizeof(device_tbl) / sizeof(device_tbl[0]);

	for (i = 0; i < len; i++) {
		if (strcmp(device_tbl[i].name, (const char *)dt_struct + 1)) {
			struct fdt_node *node;
			node->name = dt_struct + 1;
      ....
    }
  }
}