diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 446e49b56e6a..67f8303d513d 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -2041,6 +2041,25 @@ config AUTO_ZRELADDR 0xf8000000. This assumes the zImage being placed in the first 128MB from start of memory. +config EFI_STUB + bool + +config EFI + bool "UEFI runtime support" + depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL + select UCS2_STRING + select EFI_PARAMS_FROM_FDT + select EFI_STUB + select EFI_ARMSTUB + select EFI_RUNTIME_WRAPPERS + ---help--- + This option provides support for runtime services provided + by UEFI firmware (such as non-volatile variables, realtime + clock, and platform reset). A UEFI stub is also provided to + allow the kernel to be booted as an EFI application. This + is only useful for kernels that may run on systems that have + UEFI firmware. + endmenu menu "CPU Power Management" diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index 3f9a9ebc77c3..4c23a68a0917 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -167,9 +167,11 @@ if [ $(words $(ZRELADDR)) -gt 1 -a "$(CONFIG_AUTO_ZRELADDR)" = "" ]; then \ false; \ fi +efi-obj-$(CONFIG_EFI_STUB) := $(objtree)/drivers/firmware/efi/libstub/lib.a + $(obj)/vmlinux: $(obj)/vmlinux.lds $(obj)/$(HEAD) $(obj)/piggy.$(suffix_y).o \ $(addprefix $(obj)/, $(OBJS)) $(lib1funcs) $(ashldi3) \ - $(bswapsdi2) FORCE + $(bswapsdi2) $(efi-obj-y) FORCE @$(check_for_multiple_zreladdr) $(call if_changed,ld) @$(check_for_bad_syms) diff --git a/arch/arm/boot/compressed/efi-header.S b/arch/arm/boot/compressed/efi-header.S new file mode 100644 index 000000000000..9d5dc4fda3c1 --- /dev/null +++ b/arch/arm/boot/compressed/efi-header.S @@ -0,0 +1,130 @@ +/* + * Copyright (C) 2013-2015 Linaro Ltd + * Authors: Roy Franz + * Ard Biesheuvel + * + * 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. + */ + + .macro __nop +#ifdef CONFIG_EFI_STUB + @ This is almost but not quite a NOP, since it does clobber the + @ condition flags. But it is the best we can do for EFI, since + @ PE/COFF expects the magic string "MZ" at offset 0, while the + @ ARM/Linux boot protocol expects an executable instruction + @ there. + .inst 'M' | ('Z' << 8) | (0x1310 << 16) @ tstne r0, #0x4d000 +#else + mov r0, r0 +#endif + .endm + + .macro __EFI_HEADER +#ifdef CONFIG_EFI_STUB + b __efi_start + + .set start_offset, __efi_start - start + .org start + 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 - start @ Offset to the PE header. + +pe_header: + .ascii "PE\0\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 _end - __efi_start @ SizeOfCode + .long 0 @ SizeOfInitializedData + .long 0 @ SizeOfUninitializedData + .long efi_stub_entry - start @ AddressOfEntryPoint + .long start_offset @ BaseOfCode + .long 0 @ data + +extra_header_fields: + .long 0 @ ImageBase + .long 0x200 @ SectionAlignment + .long 0x200 @ FileAlignment + .short 0 @ MajorOperatingSystemVersion + .short 0 @ MinorOperatingSystemVersion + .short 0 @ MajorImageVersion + .short 0 @ MinorImageVersion + .short 0 @ MajorSubsystemVersion + .short 0 @ MinorSubsystemVersion + .long 0 @ Win32VersionValue + + .long _end - start @ SizeOfImage + .long start_offset @ 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: + @ + @ 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\0\0" + .long 0 @ VirtualSize + .long 0 @ VirtualAddress + .long 0 @ SizeOfRawData + .long 0 @ PointerToRawData + .long 0 @ PointerToRelocations + .long 0 @ PointerToLineNumbers + .short 0 @ NumberOfRelocations + .short 0 @ NumberOfLineNumbers + .long 0x42100040 @ Characteristics + + .ascii ".text\0\0\0" + .long _end - __efi_start @ VirtualSize + .long __efi_start @ VirtualAddress + .long _edata - __efi_start @ SizeOfRawData + .long __efi_start @ PointerToRawData + .long 0 @ PointerToRelocations + .long 0 @ PointerToLineNumbers + .short 0 @ NumberOfRelocations + .short 0 @ NumberOfLineNumbers + .long 0xe0500020 @ Characteristics + + .align 9 +__efi_start: +#endif + .endm diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 06e983f59980..af11c2f8f3b7 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -12,6 +12,8 @@ #include #include +#include "efi-header.S" + AR_CLASS( .arch armv7-a ) M_CLASS( .arch armv7-m ) @@ -126,7 +128,7 @@ start: .type start,#function .rept 7 - mov r0, r0 + __nop .endr ARM( mov r0, r0 ) ARM( b 1f ) @@ -139,7 +141,8 @@ start: .word 0x04030201 @ endianness flag THUMB( .thumb ) -1: +1: __EFI_HEADER + ARM_BE8( setend be ) @ go BE8 if compiled for BE8 AR_CLASS( mrs r9, cpsr ) #ifdef CONFIG_ARM_VIRT_EXT @@ -1353,6 +1356,53 @@ __enter_kernel: reloc_code_end: +#ifdef CONFIG_EFI_STUB + .align 2 +_start: .long start - . + +ENTRY(efi_stub_entry) + @ 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 ip, _start + ldr r3, [ip] + add r3, r3, ip + stmfd sp!, {r3, lr} + mov r2, sp @ pass zImage address in r2 + bl efi_entry + + @ Check for error return from EFI stub. r0 has FDT address + @ or error code. + cmn r0, #1 + beq efi_load_fail + + @ Preserve return value of efi_entry() in r4 + mov r4, r0 + bl cache_clean_flush + bl cache_off + + @ Set parameters for booting zImage according to boot protocol + @ put FDT address in r2, it was returned by efi_entry() + @ r1 is the machine type, and r0 needs to be 0 + mov r0, #0 + mov r1, #0xFFFFFFFF + mov r2, r4 + + @ Branch to (possibly) relocated zImage that is in [sp] + ldr lr, [sp] + ldr ip, =start_offset + add lr, lr, ip + mov pc, lr @ no mode switch + +efi_load_fail: + @ Return EFI_LOAD_ERROR to EFI firmware on error. + ldr r0, =0x80000001 + ldmfd sp!, {ip, pc} +ENDPROC(efi_stub_entry) +#endif + .align .section ".stack", "aw", %nobits .L_user_stack: .space 4096 diff --git a/arch/arm/boot/compressed/vmlinux.lds.S b/arch/arm/boot/compressed/vmlinux.lds.S index 2b60b843ac5e..81c493156ce8 100644 --- a/arch/arm/boot/compressed/vmlinux.lds.S +++ b/arch/arm/boot/compressed/vmlinux.lds.S @@ -48,6 +48,13 @@ SECTIONS *(.rodata) *(.rodata.*) } + .data : { + /* + * The EFI stub always executes from RAM, and runs strictly before the + * decompressor, so we can make an exception for its r/w data, and keep it + */ + *(.data.efistub) + } .piggydata : { *(.piggydata) } diff --git a/arch/arm/include/asm/efi.h b/arch/arm/include/asm/efi.h index c91e330616ad..e0eea72deb87 100644 --- a/arch/arm/include/asm/efi.h +++ b/arch/arm/include/asm/efi.h @@ -57,4 +57,27 @@ void efi_virtmap_unload(void); #define efi_init() #endif /* CONFIG_EFI */ +/* arch specific definitions used by the stub code */ + +#define efi_call_early(f, ...) sys_table_arg->boottime->f(__VA_ARGS__) + +/* + * A reasonable upper bound for the uncompressed kernel size is 32 MBytes, + * so we will reserve that amount of memory. We have no easy way to tell what + * the actuall size of code + data the uncompressed kernel will use. + * If this is insufficient, the decompressor will relocate itself out of the + * way before performing the decompression. + */ +#define MAX_UNCOMP_KERNEL_SIZE SZ_32M + +/* + * The kernel zImage should preferably be located between 32 MB and 128 MB + * 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 SZ_128M +#define MIN_ZIMAGE_OFFSET MAX_UNCOMP_KERNEL_SIZE +#define MAX_FDT_OFFSET ZIMAGE_OFFSET_LIMIT + #endif /* _ASM_ARM_EFI_H */ diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 3c0467d3688c..8cf9ccbf42d5 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -34,6 +34,7 @@ $(obj)/lib-%.o: $(srctree)/lib/%.c FORCE lib-$(CONFIG_EFI_ARMSTUB) += arm-stub.o fdt.o string.o \ $(patsubst %.c,lib-%.o,$(arm-deps)) +lib-$(CONFIG_ARM) += arm32-stub.o lib-$(CONFIG_ARM64) += arm64-stub.o CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) @@ -67,3 +68,11 @@ quiet_cmd_stubcopy = STUBCPY $@ $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y) \ && (echo >&2 "$@: absolute symbol references not allowed in the EFI stub"; \ rm -f $@; /bin/false); else /bin/false; fi + +# +# ARM discards the .data section because it disallows r/w data in the +# decompressor. So move our .data to .data.efistub, which is preserved +# explicitly by the decompressor linker script. +# +STUBCOPY_FLAGS-$(CONFIG_ARM) += --rename-section .data=.data.efistub +STUBCOPY_RELOC-$(CONFIG_ARM) := R_ARM_ABS diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c index 950c87f5d279..3397902e4040 100644 --- a/drivers/firmware/efi/libstub/arm-stub.c +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -303,8 +303,10 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table, * The value chosen is the largest non-zero power of 2 suitable for this purpose * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can * be mapped efficiently. + * Since 32-bit ARM could potentially execute with a 1G/3G user/kernel split, + * map everything below 1 GB. */ -#define EFI_RT_VIRTUAL_BASE 0x40000000 +#define EFI_RT_VIRTUAL_BASE SZ_512M static int cmp_mem_desc(const void *l, const void *r) { diff --git a/drivers/firmware/efi/libstub/arm32-stub.c b/drivers/firmware/efi/libstub/arm32-stub.c new file mode 100644 index 000000000000..495ebd657e38 --- /dev/null +++ b/drivers/firmware/efi/libstub/arm32-stub.c @@ -0,0 +1,85 @@ +/* + * Copyright (C) 2013 Linaro Ltd; + * + * 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 +#include + +efi_status_t handle_kernel_image(efi_system_table_t *sys_table, + 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) +{ + unsigned long nr_pages; + efi_status_t status; + /* Use alloc_addr to tranlsate between types */ + efi_physical_addr_t alloc_addr; + + /* + * Verify that the DRAM base address is compatible with the ARM + * boot protocol, which determines the base of DRAM by masking + * off the low 27 bits of the address at which the zImage is + * loaded. These assumptions are made by the decompressor, + * before any memory map is available. + */ + dram_base = round_up(dram_base, SZ_128M); + + /* + * 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. + * Do this very early, as prints can cause memory allocations + * that may conflict with this. + */ + alloc_addr = dram_base; + *reserve_size = MAX_UNCOMP_KERNEL_SIZE; + nr_pages = round_up(*reserve_size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE; + status = sys_table->boottime->allocate_pages(EFI_ALLOCATE_ADDRESS, + EFI_LOADER_DATA, + nr_pages, &alloc_addr); + if (status != EFI_SUCCESS) { + *reserve_size = 0; + pr_efi_err(sys_table, "Unable to allocate memory for uncompressed kernel.\n"); + return status; + } + *reserve_addr = alloc_addr; + + /* + * Relocate the zImage, so that it appears in the lowest 128 MB + * memory window. + */ + *image_size = image->image_size; + status = efi_relocate_kernel(sys_table, image_addr, *image_size, + *image_size, + dram_base + MAX_UNCOMP_KERNEL_SIZE, 0); + if (status != EFI_SUCCESS) { + pr_efi_err(sys_table, "Failed to relocate kernel.\n"); + efi_free(sys_table, *reserve_size, *reserve_addr); + *reserve_size = 0; + return status; + } + + /* + * Check to see if we were able to allocate memory low enough + * in memory. The kernel determines the base of DRAM from the + * address at which the zImage is loaded. + */ + if (*image_addr + *image_size > dram_base + ZIMAGE_OFFSET_LIMIT) { + pr_efi_err(sys_table, "Failed to relocate kernel, no low memory available.\n"); + efi_free(sys_table, *reserve_size, *reserve_addr); + *reserve_size = 0; + efi_free(sys_table, *image_size, *image_addr); + *image_size = 0; + return EFI_LOAD_ERROR; + } + return EFI_SUCCESS; +}