[V6,6/8] Add EFI stub for ARM

Message ID	1389371417-379-7-git-send-email-roy.franz@linaro.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org> From: Roy Franz <roy.franz@linaro.org> To: linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, matt.fleming@intel.com, linux@arm.linux.org.uk Subject: [PATCH V6 6/8] Add EFI stub for ARM Date: Fri, 10 Jan 2014 08:30:15 -0800 Message-Id: <1389371417-379-7-git-send-email-roy.franz@linaro.org> In-Reply-To: <1389371417-379-1-git-send-email-roy.franz@linaro.org> References: <1389371417-379-1-git-send-email-roy.franz@linaro.org> Cc: patches@linaro.org, leif.lindholm@linaro.org, Roy Franz <roy.franz@linaro.org>, msalter@redhat.com, grant.likely@linaro.org, dave.martin@arm.com Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org

diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index e7190bb..c0c7fee 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -99,11 +99,22 @@ libfdt_objs := $(addsuffix .o, $(basename $(libfdt))) $(addprefix $(obj)/,$(libfdt) $(libfdt_hdrs)): $(obj)/%: $(srctree)/scripts/dtc/libfdt/% $(call cmd,shipped) -$(addprefix $(obj)/,$(libfdt_objs) atags_to_fdt.o): \ +$(addprefix $(obj)/,$(libfdt_objs) atags_to_fdt.o efi-stub.o): \ $(addprefix $(obj)/,$(libfdt_hdrs)) ifeq ($(CONFIG_ARM_ATAG_DTB_COMPAT),y) -OBJS += $(libfdt_objs) atags_to_fdt.o +OBJS += atags_to_fdt.o +USE_LIBFDT = y +endif + +ifeq ($(CONFIG_EFI_STUB),y) +CFLAGS_efi-stub.o += -DTEXT_OFFSET=$(TEXT_OFFSET) +OBJS += efi-stub.o +USE_LIBFDT = y +endif + +ifeq ($(USE_LIBFDT),y) +OBJS += $(libfdt_objs) endif targets := vmlinux vmlinux.lds \ diff --git a/arch/arm/boot/compressed/efi-header.S b/arch/arm/boot/compressed/efi-header.S new file mode 100644 index 0000000..dbb7101 --- /dev/null +++ b/arch/arm/boot/compressed/efi-header.S @@ -0,0 +1,117 @@ +@ Copyright (C) 2013 Linaro Ltd; <roy.franz@linaro.org> +@ +@ This file contains the PE/COFF header that is part of the +@ EFI stub. +@ + + .org 0x3c + @ + @ The PE header can be anywhere in the file, but for + @ simplicity we keep it together with the MSDOS header + @ The offset to the PE/COFF header needs to be at offset + @ 0x3C in the MSDOS header. + @ The only 2 fields of the MSDOS header that are used are this + @ PE/COFF offset, and the "MZ" bytes at offset 0x0. + @ + .long pe_header @ Offset to the PE header. + + .align 3 +pe_header: + .ascii "PE" + .short 0 + +coff_header: + .short 0x01c2 @ ARM or Thumb + .short 2 @ nr_sections + .long 0 @ TimeDateStamp + .long 0 @ PointerToSymbolTable + .long 1 @ NumberOfSymbols + .short section_table - optional_header @ SizeOfOptionalHeader + .short 0x306 @ Characteristics. + @ IMAGE_FILE_32BIT_MACHINE | + @ IMAGE_FILE_DEBUG_STRIPPED | + @ IMAGE_FILE_EXECUTABLE_IMAGE | + @ IMAGE_FILE_LINE_NUMS_STRIPPED + +optional_header: + .short 0x10b @ PE32 format + .byte 0x02 @ MajorLinkerVersion + .byte 0x14 @ MinorLinkerVersion + + .long _edata - efi_stub_entry @ SizeOfCode + + .long 0 @ SizeOfInitializedData + .long 0 @ SizeOfUninitializedData + + .long efi_stub_entry @ AddressOfEntryPoint + .long efi_stub_entry @ BaseOfCode + .long 0 @ data + +extra_header_fields: + .long 0 @ ImageBase + .long 0x20 @ SectionAlignment + .long 0x8 @ FileAlignment + .short 0 @ MajorOperatingSystemVersion + .short 0 @ MinorOperatingSystemVersion + .short 0 @ MajorImageVersion + .short 0 @ MinorImageVersion + .short 0 @ MajorSubsystemVersion + .short 0 @ MinorSubsystemVersion + .long 0 @ Win32VersionValue + + .long _edata @ SizeOfImage + + @ Everything before the entry point is considered part of the header + .long efi_stub_entry @ SizeOfHeaders + .long 0 @ CheckSum + .short 0xa @ Subsystem (EFI application) + .short 0 @ DllCharacteristics + .long 0 @ SizeOfStackReserve + .long 0 @ SizeOfStackCommit + .long 0 @ SizeOfHeapReserve + .long 0 @ SizeOfHeapCommit + .long 0 @ LoaderFlags + .long 0x6 @ NumberOfRvaAndSizes + + .quad 0 @ ExportTable + .quad 0 @ ImportTable + .quad 0 @ ResourceTable + .quad 0 @ ExceptionTable + .quad 0 @ CertificationTable + .quad 0 @ BaseRelocationTable + # Section table +section_table: + + # + # The EFI application loader requires a relocation section + # because EFI applications must be relocatable. This is a + # dummy section as far as we are concerned. + # + .ascii ".reloc" + .byte 0 + .byte 0 @ end of 0 padding of section name + .long 0 + .long 0 + .long 0 @ SizeOfRawData + .long 0 @ PointerToRawData + .long 0 @ PointerToRelocations + .long 0 @ PointerToLineNumbers + .short 0 @ NumberOfRelocations + .short 0 @ NumberOfLineNumbers + .long 0x42100040 @ Characteristics (section flags) + + + .ascii ".text" + .byte 0 + .byte 0 + .byte 0 @ end of 0 padding of section name + .long _edata - efi_stub_entry @ VirtualSize + .long efi_stub_entry @ VirtualAddress + .long _edata - efi_stub_entry @ SizeOfRawData + .long efi_stub_entry @ PointerToRawData + + .long 0 @ PointerToRelocations (0 for executables) + .long 0 @ PointerToLineNumbers (0 for executables) + .short 0 @ NumberOfRelocations (0 for executables) + .short 0 @ NumberOfLineNumbers (0 for executables) + .long 0xe0500020 @ Characteristics (section flags) diff --git a/arch/arm/boot/compressed/efi-stub.c b/arch/arm/boot/compressed/efi-stub.c new file mode 100644 index 0000000..7d5feb3 --- /dev/null +++ b/arch/arm/boot/compressed/efi-stub.c @@ -0,0 +1,214 @@ +/* + * linux/arch/arm/boot/compressed/efi-stub.c + * + * Copyright (C) 2013 Linaro Ltd; <roy.franz@linaro.org> + * + * This file implements the EFI boot stub for the ARM kernel + * + * 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 <libfdt.h> +#include "efi-stub.h" + +/* EFI function call wrappers. These are not required for + * ARM, but wrappers are required for X86 to convert between + * ABIs. These wrappers are provided to allow code sharing + * between X86 and ARM. Since these wrappers directly invoke the + * EFI function pointer, the function pointer type must be properly + * defined, which is not the case for X86 One advantage of this is + * it allows for type checking of arguments, which is not + * possible with the X86 wrappers. + */ +#define efi_call_phys0(f) f() +#define efi_call_phys1(f, a1) f(a1) +#define efi_call_phys2(f, a1, a2) f(a1, a2) +#define efi_call_phys3(f, a1, a2, a3) f(a1, a2, a3) +#define efi_call_phys4(f, a1, a2, a3, a4) f(a1, a2, a3, a4) +#define efi_call_phys5(f, a1, a2, a3, a4, a5) f(a1, a2, a3, a4, a5) + +/* The maximum uncompressed kernel size is 32 MBytes, so we will reserve + * that for the decompressed kernel. We have no easy way to tell what + * the actuall size of code + data the uncompressed kernel will use. + */ +#define MAX_UNCOMP_KERNEL_SIZE 0x02000000 + +/* The kernel zImage should be located between 32 Mbytes + * and 128 MBytes from the base of DRAM. The min + * address leaves space for a maximal size uncompressed image, + * and the max address is due to how the zImage decompressor + * picks a destination address. + */ +#define ZIMAGE_OFFSET_LIMIT 0x08000000 +#define MIN_ZIMAGE_OFFSET MAX_UNCOMP_KERNEL_SIZE + +/* Include shared EFI stub code, and required headers. */ +#include "../../../../include/generated/compile.h" +#include "../../../../include/generated/utsrelease.h" +#include "../../../../drivers/firmware/efi/efi-stub-helper.c" +#include "../../../../drivers/firmware/efi/fdt.c" + + +int efi_entry(void *handle, efi_system_table_t *sys_table, + unsigned long *zimage_addr) +{ + efi_loaded_image_t *image; + int status; + unsigned long nr_pages; + const struct fdt_region *region; + + void *fdt; + int err; + int node; + unsigned long zimage_size = 0; + unsigned long dram_base; + /* addr/point and size pairs for memory management*/ + unsigned long initrd_addr; + unsigned long initrd_size = 0; + unsigned long fdt_addr; + unsigned long fdt_size = 0; + efi_physical_addr_t kernel_reserve_addr; + unsigned long kernel_reserve_size = 0; + char *cmdline_ptr; + int cmdline_size = 0; + + + unsigned long new_fdt_addr; + + /* Check if we were booted by the EFI firmware */ + if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) + goto fail; + + pr_efi(sys_table, "Booting Linux using EFI stub.\n"); + + /* Get the command line from EFI, using the LOADED_IMAGE + * protocol. We are going to copy the command line into the + * device tree, so this memory just needs to not conflict with + * boot protocol requirements. + */ + efi_get_cmdline(sys_table, &image, handle, &cmdline_ptr); + if (!cmdline_ptr) { + pr_efi_err(sys_table, "Unable to allocate memory for command line.\n"); + goto fail; + } + + /* We first load the device tree, as we need to get the base address of + * DRAM from the device tree. The zImage, device tree, and initrd + * have address restrictions that are relative to the base of DRAM. + */ + status = handle_cmdline_files(sys_table, image, cmdline_ptr, "dtb=", + 0xffffffff, &fdt_addr, &fdt_size); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Unable to load device tree blob.\n"); + goto fail_free_cmdline; + } + + err = fdt_check_header((void *)fdt_addr); + if (err != 0) { + pr_efi_err(sys_table, "Device tree header not valid.\n"); + goto fail_free_fdt; + } + if (fdt_totalsize((void *)fdt_addr) > fdt_size) { + pr_efi_err(sys_table, "Incomplete device tree.\n"); + goto fail_free_fdt; + + } + + + /* Look up the base of DRAM from the device tree. */ + fdt = (void *)fdt_addr; + node = fdt_subnode_offset(fdt, 0, "memory"); + region = fdt_getprop(fdt, node, "reg", NULL); + if (region) { + dram_base = fdt64_to_cpu(region->base); + } else { + /* There is no way to get amount or addresses of physical + * memory installed using EFI calls. If the device tree + * we read from disk doesn't have this, there is no way + * for us to construct this informaion. + */ + pr_efi_err(sys_table, "No 'memory' node in device tree.\n"); + goto fail_free_fdt; + } + + /* Reserve memory for the uncompressed kernel image. This is + * all that prevents any future allocations from conflicting + * with the kernel. Since we can't tell from the compressed + * image how much DRAM the kernel actually uses (due to BSS + * size uncertainty) we allocate the maximum possible size. + */ + kernel_reserve_addr = dram_base; + kernel_reserve_size = MAX_UNCOMP_KERNEL_SIZE; + nr_pages = round_up(kernel_reserve_size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE; + status = efi_call_phys4(sys_table->boottime->allocate_pages, + EFI_ALLOCATE_ADDRESS, EFI_LOADER_DATA, + nr_pages, &kernel_reserve_addr); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Unable to allocate memory for uncompressed kernel.\n"); + goto fail_free_fdt; + } + + /* Relocate the zImage, if required. ARM doesn't have a + * preferred address, so we set it to 0, as we want to allocate + * as low in memory as possible. + */ + zimage_size = image->image_size; + status = efi_relocate_kernel(sys_table, zimage_addr, zimage_size, + zimage_size, 0, 0); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Failed to relocate kernel.\n"); + goto fail_free_kernel_reserve; + } + + /* Check to see if we were able to allocate memory low enough + * in memory. + */ + if (*zimage_addr + zimage_size > dram_base + ZIMAGE_OFFSET_LIMIT) { + pr_efi_err(sys_table, "Failed to relocate kernel, no low memory available.\n"); + goto fail_free_zimage; + } + status = handle_cmdline_files(sys_table, image, cmdline_ptr, "initrd=", + dram_base + ZIMAGE_OFFSET_LIMIT, + &initrd_addr, &initrd_size); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Unable to load initrd.\n"); + goto fail_free_zimage; + } + + + /* + * Now we need to allocate new memory for the final FDT so that + * we can add EFI and command line related fields to it. + * This function will allocate the new FDT and update it, + * retrying memory allocations if they are too small. + * It also call + */ + status = allocate_new_fdt_and_exit_boot(sys_table, handle, + &new_fdt_addr, + dram_base + ZIMAGE_OFFSET_LIMIT, + initrd_addr, initrd_size, + cmdline_ptr, fdt_addr, + fdt_size); + if (status == EFI_SUCCESS) + return new_fdt_addr; + + efi_free(sys_table, initrd_size, initrd_addr); + +fail_free_zimage: + efi_free(sys_table, zimage_size, *zimage_addr); + +fail_free_kernel_reserve: + efi_free(sys_table, kernel_reserve_size, kernel_reserve_addr); + +fail_free_fdt: + efi_free(sys_table, fdt_size, fdt_addr); + +fail_free_cmdline: + efi_free(sys_table, cmdline_size, (u32)cmdline_ptr); + +fail: + return EFI_STUB_ERROR; +} diff --git a/arch/arm/boot/compressed/efi-stub.h b/arch/arm/boot/compressed/efi-stub.h new file mode 100644 index 0000000..0fe9376 --- /dev/null +++ b/arch/arm/boot/compressed/efi-stub.h @@ -0,0 +1,5 @@ +#ifndef _ARM_EFI_STUB_H +#define _ARM_EFI_STUB_H +/* Error code returned to ASM code instead of valid FDT address. */ +#define EFI_STUB_ERROR (~0) +#endif diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 066b034..eeb394c 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -10,6 +10,7 @@ */ #include <linux/linkage.h> #include <asm/assembler.h> +#include "efi-stub.h" .arch armv7-a /* @@ -120,22 +121,93 @@ */ .align .arm @ Always enter in ARM state + .text start: .type start,#function - .rept 7 +#ifdef CONFIG_EFI_STUB + @ Magic MSDOS signature for PE/COFF + ADD opcode + @ the EFI stub only supports little endian, as the EFI functions + @ it invokes are little endian. + .word 0x62805a4d +#else + mov r0, r0 +#endif + .rept 5 mov r0, r0 .endr - ARM( mov r0, r0 ) - ARM( b 1f ) - THUMB( adr r12, BSYM(1f) ) - THUMB( bx r12 ) + + adrl r12, BSYM(zimage_continue) + ARM( mov pc, r12 ) + THUMB( bx r12 ) + @ zimage_continue will be in ARM or thumb mode as configured .word 0x016f2818 @ Magic numbers to help the loader .word start @ absolute load/run zImage address .word _edata @ zImage end address + +#ifdef CONFIG_EFI_STUB + @ Portions of the MSDOS file header must be at offset + @ 0x3c from the start of the file. All PE/COFF headers + @ are kept contiguous for simplicity. +#include "efi-header.S" + +efi_stub_entry: + @ The EFI stub entry point is not at a fixed address, however + @ this address must be set in the PE/COFF header. + @ EFI entry point is in A32 mode, switch to T32 if configured. + THUMB( adr r12, BSYM(1f) ) + THUMB( bx r12 ) THUMB( .thumb ) 1: ARM_BE8( setend be ) @ go BE8 if compiled for BE8 + @ Save lr on stack for possible return to EFI firmware. + @ Don't care about fp, but need 64 bit alignment.... + stmfd sp!, {fp, lr} + + @ allocate space on stack for passing current zImage address + @ and for the EFI stub to return of new entry point of + @ zImage, as EFI stub may copy the kernel. Pointer address + @ is passed in r2. r0 and r1 are passed through from the + @ EFI firmware to efi_entry + adr r3, start + str r3, [sp, #-8]! + mov r2, sp @ pass pointer in r2 + bl efi_entry + ldr r3, [sp], #8 @ get new zImage address from stack + + @ Check for error return from EFI stub. r0 has FDT address + @ or EFI_STUB_ERROR error code. + cmp r0, #EFI_STUB_ERROR + beq efi_load_fail + + @ Save return values of efi_entry + stmfd sp!, {r0, r3} + bl cache_clean_flush + bl cache_off + ldmfd sp!, {r0, r3} + + @ Set parameters for booting zImage according to boot protocol + @ put FDT address in r2, it was returned by efi_entry() + @ r1 is FDT machine type, and r0 needs to be 0 + mov r2, r0 + mov r1, #0xFFFFFFFF + mov r0, #0 + + @ Branch to (possibly) relocated zImage that is in r3 + @ Make sure we are in A32 mode, as zImage requires + THUMB( bx r3 ) + ARM( mov pc, r3 ) + +efi_load_fail: + @ Return EFI_LOAD_ERROR to EFI firmware on error. + @ Switch back to ARM mode for EFI is done based on + @ return address on stack in case we are in THUMB mode + ldr r0, =0x80000001 + ldmfd sp!, {fp, pc} @ put lr from stack into pc +#endif + + THUMB( .thumb ) +zimage_continue: mrs r9, cpsr #ifdef CONFIG_ARM_VIRT_EXT bl __hyp_stub_install @ get into SVC mode, reversibly @@ -168,7 +240,6 @@ not_angel: * by the linker here, but it should preserve r7, r8, and r9. */ - .text #ifdef CONFIG_AUTO_ZRELADDR @ determine final kernel image address

[V6,6/8] Add EFI stub for ARM

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