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kernel/linux-rt-4.4.41/drivers/firmware/efi/libstub/arm64-stub.c 2.61 KB
5113f6f70   김현기   kernel add
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  /*
   * Copyright (C) 2013, 2014 Linaro Ltd;  <roy.franz@linaro.org>
   *
   * This file implements the EFI boot stub for the arm64 kernel.
   * Adapted from ARM version by Mark Salter <msalter@redhat.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   */
  #include <linux/efi.h>
  #include <asm/efi.h>
  #include <asm/sections.h>
  
  efi_status_t __init handle_kernel_image(efi_system_table_t *sys_table_arg,
  					unsigned long *image_addr,
  					unsigned long *image_size,
  					unsigned long *reserve_addr,
  					unsigned long *reserve_size,
  					unsigned long dram_base,
  					efi_loaded_image_t *image)
  {
  	efi_status_t status;
  	unsigned long kernel_size, kernel_memsize = 0;
  	unsigned long nr_pages;
  	void *old_image_addr = (void *)*image_addr;
  	unsigned long preferred_offset;
  
  	/*
  	 * The preferred offset of the kernel Image is TEXT_OFFSET bytes beyond
  	 * a 2 MB aligned base, which itself may be lower than dram_base, as
  	 * long as the resulting offset equals or exceeds it.
  	 */
  	preferred_offset = round_down(dram_base, SZ_2M) + TEXT_OFFSET;
  	if (preferred_offset < dram_base)
  		preferred_offset += SZ_2M;
  
  	/* Relocate the image, if required. */
  	kernel_size = _edata - _text;
  	if (*image_addr != preferred_offset) {
  		kernel_memsize = kernel_size + (_end - _edata);
  
  		/*
  		 * First, try a straight allocation at the preferred offset.
  		 * This will work around the issue where, if dram_base == 0x0,
  		 * efi_low_alloc() refuses to allocate at 0x0 (to prevent the
  		 * address of the allocation to be mistaken for a FAIL return
  		 * value or a NULL pointer). It will also ensure that, on
  		 * platforms where the [dram_base, dram_base + TEXT_OFFSET)
  		 * interval is partially occupied by the firmware (like on APM
  		 * Mustang), we can still place the kernel at the address
  		 * 'dram_base + TEXT_OFFSET'.
  		 */
  		*image_addr = *reserve_addr = preferred_offset;
  		nr_pages = round_up(kernel_memsize, EFI_ALLOC_ALIGN) /
  			   EFI_PAGE_SIZE;
  		status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS,
  					EFI_LOADER_DATA, nr_pages,
  					(efi_physical_addr_t *)reserve_addr);
  		if (status != EFI_SUCCESS) {
  			kernel_memsize += TEXT_OFFSET;
  			status = efi_low_alloc(sys_table_arg, kernel_memsize,
  					       SZ_2M, reserve_addr);
  
  			if (status != EFI_SUCCESS) {
  				pr_efi_err(sys_table_arg, "Failed to relocate kernel
  ");
  				return status;
  			}
  			*image_addr = *reserve_addr + TEXT_OFFSET;
  		}
  		memcpy((void *)*image_addr, old_image_addr, kernel_size);
  		*reserve_size = kernel_memsize;
  	}
  
  
  	return EFI_SUCCESS;
  }