1 /* 2 * Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@linaro.org> 3 * 4 * This file implements the EFI boot stub for the arm64 kernel. 5 * Adapted from ARM version by Mark Salter <msalter@redhat.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 */ 12 #include <linux/efi.h> 13 #include <asm/efi.h> 14 #include <asm/sections.h> 15 16 efi_status_t __init handle_kernel_image(efi_system_table_t *sys_table_arg, 17 unsigned long *image_addr, 18 unsigned long *image_size, 19 unsigned long *reserve_addr, 20 unsigned long *reserve_size, 21 unsigned long dram_base, 22 efi_loaded_image_t *image) 23 { 24 efi_status_t status; 25 unsigned long kernel_size, kernel_memsize = 0; 26 unsigned long nr_pages; 27 void *old_image_addr = (void *)*image_addr; 28 unsigned long preferred_offset; 29 30 /* 31 * The preferred offset of the kernel Image is TEXT_OFFSET bytes beyond 32 * a 2 MB aligned base, which itself may be lower than dram_base, as 33 * long as the resulting offset equals or exceeds it. 34 */ 35 preferred_offset = round_down(dram_base, SZ_2M) + TEXT_OFFSET; 36 if (preferred_offset < dram_base) 37 preferred_offset += SZ_2M; 38 39 /* Relocate the image, if required. */ 40 kernel_size = _edata - _text; 41 if (*image_addr != preferred_offset) { 42 kernel_memsize = kernel_size + (_end - _edata); 43 44 /* 45 * First, try a straight allocation at the preferred offset. 46 * This will work around the issue where, if dram_base == 0x0, 47 * efi_low_alloc() refuses to allocate at 0x0 (to prevent the 48 * address of the allocation to be mistaken for a FAIL return 49 * value or a NULL pointer). It will also ensure that, on 50 * platforms where the [dram_base, dram_base + TEXT_OFFSET) 51 * interval is partially occupied by the firmware (like on APM 52 * Mustang), we can still place the kernel at the address 53 * 'dram_base + TEXT_OFFSET'. 54 */ 55 *image_addr = *reserve_addr = preferred_offset; 56 nr_pages = round_up(kernel_memsize, EFI_ALLOC_ALIGN) / 57 EFI_PAGE_SIZE; 58 status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS, 59 EFI_LOADER_DATA, nr_pages, 60 (efi_physical_addr_t *)reserve_addr); 61 if (status != EFI_SUCCESS) { 62 kernel_memsize += TEXT_OFFSET; 63 status = efi_low_alloc(sys_table_arg, kernel_memsize, 64 SZ_2M, reserve_addr); 65 66 if (status != EFI_SUCCESS) { 67 pr_efi_err(sys_table_arg, "Failed to relocate kernel\n"); 68 return status; 69 } 70 *image_addr = *reserve_addr + TEXT_OFFSET; 71 } 72 memcpy((void *)*image_addr, old_image_addr, kernel_size); 73 *reserve_size = kernel_memsize; 74 } 75 76 77 return EFI_SUCCESS; 78 } 79