1bf457786SArd Biesheuvel /* 2bf457786SArd Biesheuvel * Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@linaro.org> 3bf457786SArd Biesheuvel * 4bf457786SArd Biesheuvel * This file implements the EFI boot stub for the arm64 kernel. 5bf457786SArd Biesheuvel * Adapted from ARM version by Mark Salter <msalter@redhat.com> 6bf457786SArd Biesheuvel * 7bf457786SArd Biesheuvel * This program is free software; you can redistribute it and/or modify 8bf457786SArd Biesheuvel * it under the terms of the GNU General Public License version 2 as 9bf457786SArd Biesheuvel * published by the Free Software Foundation. 10bf457786SArd Biesheuvel * 11bf457786SArd Biesheuvel */ 12bf457786SArd Biesheuvel #include <linux/efi.h> 13bf457786SArd Biesheuvel #include <asm/efi.h> 14bf457786SArd Biesheuvel #include <asm/sections.h> 15bf457786SArd Biesheuvel 16bf457786SArd Biesheuvel efi_status_t __init handle_kernel_image(efi_system_table_t *sys_table_arg, 17bf457786SArd Biesheuvel unsigned long *image_addr, 18bf457786SArd Biesheuvel unsigned long *image_size, 19bf457786SArd Biesheuvel unsigned long *reserve_addr, 20bf457786SArd Biesheuvel unsigned long *reserve_size, 21bf457786SArd Biesheuvel unsigned long dram_base, 22bf457786SArd Biesheuvel efi_loaded_image_t *image) 23bf457786SArd Biesheuvel { 24bf457786SArd Biesheuvel efi_status_t status; 25bf457786SArd Biesheuvel unsigned long kernel_size, kernel_memsize = 0; 26bf457786SArd Biesheuvel unsigned long nr_pages; 27bf457786SArd Biesheuvel void *old_image_addr = (void *)*image_addr; 282dc10ad8SLinus Torvalds unsigned long preferred_offset; 292dc10ad8SLinus Torvalds 302dc10ad8SLinus Torvalds /* 312dc10ad8SLinus Torvalds * The preferred offset of the kernel Image is TEXT_OFFSET bytes beyond 322dc10ad8SLinus Torvalds * a 2 MB aligned base, which itself may be lower than dram_base, as 332dc10ad8SLinus Torvalds * long as the resulting offset equals or exceeds it. 342dc10ad8SLinus Torvalds */ 352dc10ad8SLinus Torvalds preferred_offset = round_down(dram_base, SZ_2M) + TEXT_OFFSET; 362dc10ad8SLinus Torvalds if (preferred_offset < dram_base) 372dc10ad8SLinus Torvalds preferred_offset += SZ_2M; 38bf457786SArd Biesheuvel 39bf457786SArd Biesheuvel /* Relocate the image, if required. */ 40bf457786SArd Biesheuvel kernel_size = _edata - _text; 412dc10ad8SLinus Torvalds if (*image_addr != preferred_offset) { 42bf457786SArd Biesheuvel kernel_memsize = kernel_size + (_end - _edata); 43bf457786SArd Biesheuvel 44bf457786SArd Biesheuvel /* 45bf457786SArd Biesheuvel * First, try a straight allocation at the preferred offset. 46bf457786SArd Biesheuvel * This will work around the issue where, if dram_base == 0x0, 47bf457786SArd Biesheuvel * efi_low_alloc() refuses to allocate at 0x0 (to prevent the 48bf457786SArd Biesheuvel * address of the allocation to be mistaken for a FAIL return 49bf457786SArd Biesheuvel * value or a NULL pointer). It will also ensure that, on 50bf457786SArd Biesheuvel * platforms where the [dram_base, dram_base + TEXT_OFFSET) 51bf457786SArd Biesheuvel * interval is partially occupied by the firmware (like on APM 52bf457786SArd Biesheuvel * Mustang), we can still place the kernel at the address 53bf457786SArd Biesheuvel * 'dram_base + TEXT_OFFSET'. 54bf457786SArd Biesheuvel */ 552dc10ad8SLinus Torvalds *image_addr = *reserve_addr = preferred_offset; 56bf457786SArd Biesheuvel nr_pages = round_up(kernel_memsize, EFI_ALLOC_ALIGN) / 57bf457786SArd Biesheuvel EFI_PAGE_SIZE; 58bf457786SArd Biesheuvel status = efi_call_early(allocate_pages, EFI_ALLOCATE_ADDRESS, 59bf457786SArd Biesheuvel EFI_LOADER_DATA, nr_pages, 60bf457786SArd Biesheuvel (efi_physical_addr_t *)reserve_addr); 61bf457786SArd Biesheuvel if (status != EFI_SUCCESS) { 62bf457786SArd Biesheuvel kernel_memsize += TEXT_OFFSET; 63bf457786SArd Biesheuvel status = efi_low_alloc(sys_table_arg, kernel_memsize, 64bf457786SArd Biesheuvel SZ_2M, reserve_addr); 65bf457786SArd Biesheuvel 66bf457786SArd Biesheuvel if (status != EFI_SUCCESS) { 67bf457786SArd Biesheuvel pr_efi_err(sys_table_arg, "Failed to relocate kernel\n"); 68bf457786SArd Biesheuvel return status; 69bf457786SArd Biesheuvel } 70bf457786SArd Biesheuvel *image_addr = *reserve_addr + TEXT_OFFSET; 71bf457786SArd Biesheuvel } 72bf457786SArd Biesheuvel memcpy((void *)*image_addr, old_image_addr, kernel_size); 73bf457786SArd Biesheuvel *reserve_size = kernel_memsize; 74bf457786SArd Biesheuvel } 75bf457786SArd Biesheuvel 76bf457786SArd Biesheuvel 77bf457786SArd Biesheuvel return EFI_SUCCESS; 78bf457786SArd Biesheuvel } 79