When running U-Boot as an EFI application we cannot relocate since we do not have relocation information. U-Boot has already been relocated to a suitable address.

Add a global_data flag to control skipping relocation.

Signed-off-by: Simon Glass sjg@chromium.org ---

Changes in v3: None Changes in v2: None

common/board_f.c | 7 +++++++ include/asm-generic/global_data.h | 1 + 2 files changed, 8 insertions(+)

diff --git a/common/board_f.c b/common/board_f.c index 6d922b8..c596083 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -664,6 +664,11 @@ static int reloc_fdt(void)

static int setup_reloc(void) { + if (gd->flags & GD_FLG_SKIP_RELOC) { + debug("Skipping relocation due to flag\n"); + return 0; + } + #ifdef CONFIG_SYS_TEXT_BASE gd->reloc_off = gd->relocaddr - CONFIG_SYS_TEXT_BASE; #ifdef CONFIG_M68K @@ -689,6 +694,8 @@ static int setup_reloc(void)

static int jump_to_copy(void) { + if (gd->flags & GD_FLG_SKIP_RELOC) + return 0; /* * x86 is special, but in a nice way. It uses a trampoline which * enables the dcache if possible. diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h index 9f5db0f..2155265 100644 --- a/include/asm-generic/global_data.h +++ b/include/asm-generic/global_data.h @@ -117,5 +117,6 @@ typedef struct global_data { #define GD_FLG_SERIAL_READY 0x00100 /* Pre-reloc serial console ready */ #define GD_FLG_FULL_MALLOC_INIT 0x00200 /* Full malloc() is ready */ #define GD_FLG_SPL_INIT 0x00400 /* spl_init() has been called */ +#define GD_FLG_SKIP_RELOC 0x00800 /* Don't relocate */

#endif /* __ASM_GENERIC_GBL_DATA_H */

Add support for building U-Boot as an EFI application with a .efi suffix. This can be loaded by EFI provided that EFI has the same bit width (32- or 64-bit) as U-Boot. This unfortunate limitation is imposed by EFI.

Signed-off-by: Simon Glass sjg@chromium.org ---

Changes in v3: - Move the rename to u-boot-app.efi into this patch - Update the patch subject

Changes in v2: - Rename CONFIG_ARCH_EFI to CONFIG_EFI_APP

Makefile | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/Makefile b/Makefile index 1b03357..620c18f 100644 --- a/Makefile +++ b/Makefile @@ -754,6 +754,7 @@ ifneq ($(CONFIG_SPL_TARGET),) ALL-$(CONFIG_SPL) += $(CONFIG_SPL_TARGET:"%"=%) endif ALL-$(CONFIG_REMAKE_ELF) += u-boot.elf +ALL-$(CONFIG_EFI_APP) += u-boot-app.efi

ifneq ($(BUILD_ROM),) ALL-$(CONFIG_X86_RESET_VECTOR) += u-boot.rom @@ -1082,6 +1083,10 @@ u-boot-dtb-tegra.bin: u-boot-nodtb-tegra.bin dts/dt.dtb FORCE endif endif

+OBJCOPYFLAGS_u-boot-app.efi := $(OBJCOPYFLAGS_EFI) +u-boot-app.efi: u-boot FORCE + $(call if_changed,zobjcopy) + u-boot-img.bin: spl/u-boot-spl.bin u-boot.img FORCE $(call if_changed,cat)

Bring in this file from Linux 4.1. It supports relocation features specific to x86.

Signed-off-by: Simon Glass sjg@chromium.org Reviewed-by: Bin Meng bmeng.cn@gmail.com ---

Changes in v3: None Changes in v2: - Drop unneeded include of asm/ptrace.h - Fix comment style

arch/x86/include/asm/elf.h | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 arch/x86/include/asm/elf.h

diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h new file mode 100644 index 0000000..3bdcdfe --- /dev/null +++ b/arch/x86/include/asm/elf.h @@ -0,0 +1,46 @@ +/* + * Brought in from Linux 4.1, removed things not useful to U-Boot. + * The definitions perhaps came from the GNU Library which is GPL. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef _ASM_X86_ELF_H +#define _ASM_X86_ELF_H + +/* ELF register definitions */ +#define R_386_NONE 0 +#define R_386_32 1 +#define R_386_PC32 2 +#define R_386_GOT32 3 +#define R_386_PLT32 4 +#define R_386_COPY 5 +#define R_386_GLOB_DAT 6 +#define R_386_JMP_SLOT 7 +#define R_386_RELATIVE 8 +#define R_386_GOTOFF 9 +#define R_386_GOTPC 10 +#define R_386_NUM 11 + +/* x86-64 relocation types */ +#define R_X86_64_NONE 0 /* No reloc */ +#define R_X86_64_64 1 /* Direct 64 bit */ +#define R_X86_64_PC32 2 /* PC relative 32 bit signed */ +#define R_X86_64_GOT32 3 /* 32 bit GOT entry */ +#define R_X86_64_PLT32 4 /* 32 bit PLT address */ +#define R_X86_64_COPY 5 /* Copy symbol at runtime */ +#define R_X86_64_GLOB_DAT 6 /* Create GOT entry */ +#define R_X86_64_JUMP_SLOT 7 /* Create PLT entry */ +#define R_X86_64_RELATIVE 8 /* Adjust by program base */ +/* 32 bit signed pc relative offset to GOT */ +#define R_X86_64_GOTPCREL 9 +#define R_X86_64_32 10 /* Direct 32 bit zero extended */ +#define R_X86_64_32S 11 /* Direct 32 bit sign extended */ +#define R_X86_64_16 12 /* Direct 16 bit zero extended */ +#define R_X86_64_PC16 13 /* 16 bit sign extended pc relative */ +#define R_X86_64_8 14 /* Direct 8 bit sign extended */ +#define R_X86_64_PC8 15 /* 8 bit sign extended pc relative */ + +#define R_X86_64_NUM 16 + +#endif

From: Ben Stoltz stoltz@google.com

Add the required x86 glue code. This includes the initial start-up, relocation and jumping to efi_main(). We also need to avoid fiddling with interrupts.

Signed-off-by: Ben Stoltz stoltz@google.com Signed-off-by: Simon Glass sjg@chromium.org ---

Changes in v3: - Move u-boot-app.efi Makefile change to the earlier patch - Use "BSD-2-Clause" for the SPDX license

Changes in v2: - Add ALIGN() before .dynamic in the linker script - Add a blank line before return in the _relocate() function - Add a comment as to why .hash has to be first in the linker script - Add a comment as to why interrupt_init() must be skipped for EFI - Drop unused DECLARE_GLOBAL_DATA_INIT - Drop unused board_eth_init() - Drop use of CONFIG_X86_64 since we don't support a 64-bit EFI application yet - Fix spacing around operators - Move 64-bit crt0 to a later patch - Move crt0 and reloc files into arch/x86/lib/efi/ - Remove KEEP in the EFI linker script since garbage collection is not enabled - Rename CONFIG_ARCH_EFI to CONFIG_EFI_APP - Rename ImageBase to image_base - Use SPDX for the EFI start and relocation code - Use u-boot-app.efi instead of u-boot.efi

arch/x86/Kconfig | 3 ++ arch/x86/Makefile | 2 + arch/x86/cpu/Makefile | 1 + arch/x86/cpu/efi/Makefile | 8 +++ arch/x86/cpu/efi/efi.c | 42 ++++++++++++++++ arch/x86/cpu/efi/elf_ia32_efi.lds | 94 ++++++++++++++++++++++++++++++++++++ arch/x86/cpu/efi/sdram.c | 29 +++++++++++ arch/x86/cpu/interrupts.c | 6 +++ arch/x86/include/asm/arch-efi/gpio.h | 10 ++++ arch/x86/lib/efi/crt0-efi-ia32.S | 52 ++++++++++++++++++++ arch/x86/lib/efi/reloc_ia32.c | 72 +++++++++++++++++++++++++++ 11 files changed, 319 insertions(+) create mode 100644 arch/x86/cpu/efi/Makefile create mode 100644 arch/x86/cpu/efi/efi.c create mode 100644 arch/x86/cpu/efi/elf_ia32_efi.lds create mode 100644 arch/x86/cpu/efi/sdram.c create mode 100644 arch/x86/include/asm/arch-efi/gpio.h create mode 100644 arch/x86/lib/efi/crt0-efi-ia32.S create mode 100644 arch/x86/lib/efi/reloc_ia32.c

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index e8968a7..7e6e89c 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -11,6 +11,9 @@ choice config VENDOR_COREBOOT bool "coreboot"

+config VENDOR_EFI + bool "efi" + config VENDOR_EMULATION bool "emulation"

diff --git a/arch/x86/Makefile b/arch/x86/Makefile index 36a6018..d104a49 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -2,7 +2,9 @@ # SPDX-License-Identifier: GPL-2.0+ #

+ifeq ($(CONFIG_EFI_APP),) head-y := arch/x86/cpu/start.o +endif ifeq ($(CONFIG_SPL_BUILD),y) head-y += arch/x86/cpu/start16.o head-y += arch/x86/cpu/resetvec.o diff --git a/arch/x86/cpu/Makefile b/arch/x86/cpu/Makefile index 8a8e63e..5e058c0 100644 --- a/arch/x86/cpu/Makefile +++ b/arch/x86/cpu/Makefile @@ -14,6 +14,7 @@ obj-y += interrupts.o cpu.o cpu_x86.o call64.o

obj-$(CONFIG_INTEL_BAYTRAIL) += baytrail/ obj-$(CONFIG_SYS_COREBOOT) += coreboot/ +obj-$(CONFIG_EFI_APP) += efi/ obj-$(CONFIG_QEMU) += qemu/ obj-$(CONFIG_NORTHBRIDGE_INTEL_SANDYBRIDGE) += ivybridge/ obj-$(CONFIG_NORTHBRIDGE_INTEL_IVYBRIDGE) += ivybridge/ diff --git a/arch/x86/cpu/efi/Makefile b/arch/x86/cpu/efi/Makefile new file mode 100644 index 0000000..e091637 --- /dev/null +++ b/arch/x86/cpu/efi/Makefile @@ -0,0 +1,8 @@ +# +# Copyright (c) 2015 Google, Inc +# +# SPDX-License-Identifier: GPL-2.0+ +# + +obj-y += efi.o +obj-y += sdram.o diff --git a/arch/x86/cpu/efi/efi.c b/arch/x86/cpu/efi/efi.c new file mode 100644 index 0000000..75ba0d4 --- /dev/null +++ b/arch/x86/cpu/efi/efi.c @@ -0,0 +1,42 @@ +/* + * Copyright (c) 2015 Google, Inc + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <fdtdec.h> +#include <netdev.h> + +int arch_cpu_init(void) +{ +#ifdef CONFIG_SYS_X86_TSC_TIMER + timer_set_base(rdtsc()); +#endif + + return 0; +} + +int board_early_init_f(void) +{ + return 0; +} + +int print_cpuinfo(void) +{ + return default_print_cpuinfo(); +} + +void board_final_cleanup(void) +{ +} + +int misc_init_r(void) +{ + return 0; +} + +int arch_misc_init(void) +{ + return 0; +} diff --git a/arch/x86/cpu/efi/elf_ia32_efi.lds b/arch/x86/cpu/efi/elf_ia32_efi.lds new file mode 100644 index 0000000..cd3b0a9 --- /dev/null +++ b/arch/x86/cpu/efi/elf_ia32_efi.lds @@ -0,0 +1,94 @@ +/* + * U-Boot EFI linker script + * + * SPDX-License-Identifier: BSD-2-Clause + * + * Modified from usr/lib32/elf_ia32_efi.lds in gnu-efi + */ + +#include <config.h> + +OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386") +OUTPUT_ARCH(i386) +ENTRY(_start) +SECTIONS +{ + image_base = .; + .hash : { *(.hash) } /* this MUST come first, EFI expects it */ + . = ALIGN(4096); + .text : + { + *(.text) + *(.text.*) + *(.gnu.linkonce.t.*) + } + . = ALIGN(4096); + .sdata : + { + *(.got.plt) + *(.got) + *(.srodata) + *(.sdata) + *(.sbss) + *(.scommon) + } + . = ALIGN(4096); + .data : + { + *(.rodata*) + *(.data) + *(.data1) + *(.data.*) + *(.sdata) + *(.got.plt) + *(.got) + /* + * the EFI loader doesn't seem to like a .bss section, so we + * stick it all into .data: + */ + *(.sbss) + *(.scommon) + *(.dynbss) + *(.bss) + *(COMMON) + + /* U-Boot lists and device tree */ + . = ALIGN(8); + *(SORT(.u_boot_list*)); + . = ALIGN(8); + *(.dtb*); + } + + . = ALIGN(4096); + .dynamic : { *(.dynamic) } + . = ALIGN(4096); + .rel : + { + *(.rel.data) + *(.rel.data.*) + *(.rel.got) + *(.rel.stab) + *(.data.rel.ro.local) + *(.data.rel.local) + *(.data.rel.ro) + *(.data.rel*) + *(.rel.u_boot_list*) + } + . = ALIGN(4096); + .reloc : /* This is the PECOFF .reloc section! */ + { + *(.reloc) + } + . = ALIGN(4096); + .dynsym : { *(.dynsym) } + . = ALIGN(4096); + .dynstr : { *(.dynstr) } + . = ALIGN(4096); + /DISCARD/ : + { + *(.rel.reloc) + *(.eh_frame) + *(.note.GNU-stack) + } + .comment 0 : { *(.comment) } +} diff --git a/arch/x86/cpu/efi/sdram.c b/arch/x86/cpu/efi/sdram.c new file mode 100644 index 0000000..5159944 --- /dev/null +++ b/arch/x86/cpu/efi/sdram.c @@ -0,0 +1,29 @@ +/* + * Copyright (c) 2015 Google, Inc + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <efi.h> +#include <asm/u-boot-x86.h> + +DECLARE_GLOBAL_DATA_PTR; + +ulong board_get_usable_ram_top(ulong total_size) +{ + return (ulong)efi_get_ram_base() + gd->ram_size; +} + +int dram_init(void) +{ + /* gd->ram_size is set as part of EFI init */ + + return 0; +} + +void dram_init_banksize(void) +{ + gd->bd->bi_dram[0].start = efi_get_ram_base(); + gd->bd->bi_dram[0].size = CONFIG_EFI_RAM_SIZE; +} diff --git a/arch/x86/cpu/interrupts.c b/arch/x86/cpu/interrupts.c index 3a9c2d4..a112938 100644 --- a/arch/x86/cpu/interrupts.c +++ b/arch/x86/cpu/interrupts.c @@ -242,6 +242,11 @@ int disable_interrupts(void)

int interrupt_init(void) { + /* + * When running as an EFI application we are not in control of + * interrupts and should leave them alone. + */ +#ifndef CONFIG_EFI_APP /* Just in case... */ disable_interrupts();

@@ -255,6 +260,7 @@ int interrupt_init(void)

/* It is now safe to enable interrupts */ enable_interrupts(); +#endif

return 0; } diff --git a/arch/x86/include/asm/arch-efi/gpio.h b/arch/x86/include/asm/arch-efi/gpio.h new file mode 100644 index 0000000..f044f07 --- /dev/null +++ b/arch/x86/include/asm/arch-efi/gpio.h @@ -0,0 +1,10 @@ +/* + * Copyright (c) 2015 Google, Inc. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#ifndef _X86_ARCH_GPIO_H_ +#define _X86_ARCH_GPIO_H_ + +#endif /* _X86_ARCH_GPIO_H_ */ diff --git a/arch/x86/lib/efi/crt0-efi-ia32.S b/arch/x86/lib/efi/crt0-efi-ia32.S new file mode 100644 index 0000000..30e5eb0 --- /dev/null +++ b/arch/x86/lib/efi/crt0-efi-ia32.S @@ -0,0 +1,52 @@ +/* + * crt0-efi-ia32.S - x86 EFI startup code. + * + * Copyright (C) 1999 Hewlett-Packard Co. + * Contributed by David Mosberger davidm@hpl.hp.com. + * All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + + .text + .align 4 + + .globl _start +_start: + pushl %ebp + movl %esp,%ebp + + pushl 12(%ebp) # copy "image" argument + pushl 8(%ebp) # copy "systab" argument + + call 0f +0: popl %eax + movl %eax,%ebx + + addl $image_base-0b,%eax # %eax = ldbase + addl $_DYNAMIC-0b,%ebx # %ebx = _DYNAMIC + + pushl %ebx # pass _DYNAMIC as second argument + pushl %eax # pass ldbase as first argument + call _relocate + popl %ebx + popl %ebx + testl %eax,%eax + jne .exit + call efi_main # call app with "image" and "systab" argument + +.exit: leave + ret + + /* + * hand-craft a dummy .reloc section so EFI knows it's a relocatable + * executable: + */ + .data +dummy: .long 0 + +#define IMAGE_REL_ABSOLUTE 0 + .section .reloc + .long dummy /* Page RVA */ + .long 10 /* Block Size (2*4+2) */ + .word (IMAGE_REL_ABSOLUTE << 12) + 0 /* reloc for dummy */ diff --git a/arch/x86/lib/efi/reloc_ia32.c b/arch/x86/lib/efi/reloc_ia32.c new file mode 100644 index 0000000..4d68255 --- /dev/null +++ b/arch/x86/lib/efi/reloc_ia32.c @@ -0,0 +1,72 @@ +/* + * reloc_ia32.c - position independent x86 ELF shared object relocator + * Copyright (C) 1999 Hewlett-Packard Co. + * Contributed by David Mosberger davidm@hpl.hp.com. + * + * All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <common.h> +#include <efi.h> +#include <elf.h> +#include <asm/elf.h> + +efi_status_t _relocate(long ldbase, Elf32_Dyn *dyn, efi_handle_t image, + struct efi_system_table *systab) +{ + long relsz = 0, relent = 0; + Elf32_Rel *rel = 0; + unsigned long *addr; + int i; + + for (i = 0; dyn[i].d_tag != DT_NULL; ++i) { + switch (dyn[i].d_tag) { + case DT_REL: + rel = (Elf32_Rel *)((unsigned long)dyn[i].d_un.d_ptr + + ldbase); + break; + + case DT_RELSZ: + relsz = dyn[i].d_un.d_val; + break; + + case DT_RELENT: + relent = dyn[i].d_un.d_val; + break; + + case DT_RELA: + break; + + default: + break; + } + } + + if (!rel && relent == 0) + return EFI_SUCCESS; + + if (!rel || relent == 0) + return EFI_LOAD_ERROR; + + while (relsz > 0) { + /* apply the relocs */ + switch (ELF32_R_TYPE(rel->r_info)) { + case R_386_NONE: + break; + + case R_386_RELATIVE: + addr = (unsigned long *)(ldbase + rel->r_offset); + *addr += ldbase; + break; + + default: + break; + } + rel = (Elf32_Rel *)((char *)rel + relent); + relsz -= relent; + } + + return EFI_SUCCESS; +}

This contains just enough to bring up the serial UART.

Signed-off-by: Simon Glass sjg@chromium.org Reviewed-by: Bin Meng bmeng.cn@gmail.com ---

Changes in v3: None Changes in v2: - Remove extraneous '+' in comment - Use "efi,app" instead of "efi,payload" for the compatible string

arch/x86/dts/Makefile | 1 + arch/x86/dts/efi.dts | 22 ++++++++++++++++++++++ 2 files changed, 23 insertions(+) create mode 100644 arch/x86/dts/efi.dts

diff --git a/arch/x86/dts/Makefile b/arch/x86/dts/Makefile index 44e2829..71595c7 100644 --- a/arch/x86/dts/Makefile +++ b/arch/x86/dts/Makefile @@ -2,6 +2,7 @@ dtb-y += bayleybay.dtb \ chromebook_link.dtb \ chromebox_panther.dtb \ crownbay.dtb \ + efi.dtb \ galileo.dtb \ minnowmax.dtb \ qemu-x86_i440fx.dtb \ diff --git a/arch/x86/dts/efi.dts b/arch/x86/dts/efi.dts new file mode 100644 index 0000000..1f50428 --- /dev/null +++ b/arch/x86/dts/efi.dts @@ -0,0 +1,22 @@ +/* + * Copyright (c) 2015 Google, Inc + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +/dts-v1/; + +/include/ "skeleton.dtsi" + +/ { + model = "EFI"; + compatible = "efi,app"; + + chosen { + stdout-path = &serial; + }; + + serial: serial { + compatible = "efi,uart"; + }; +};

Add a linker script and relocation code for building 64-bit EFI applications. This can be used for the EFI stub.

Signed-off-by: Simon Glass sjg@chromium.org Improvements to how the payload is built: Signed-off-by: Bin Meng bmeng.cn@gmail.com Reviewed-by: Bin Meng bmeng.cn@gmail.com ---

Changes in v3: - Use "BSD-2-Clause" for the SPDX license

Changes in v2: - Add a comment as to why .hash has to be first in the linker script - Change 'link script' to 'linker script' - Drop . = 0x0; - Fix reference to elf_ia32_efi instead of elf_x86_64_efi - Merge in Bin's implementation of adding a U-Boot payload with objcopy - Remove KEEP in the EFI linker script since garbage collection is not enabled - Rename ImageBase to image_base - Update based on the elf.h changes

arch/x86/cpu/efi/elf_x86_64_efi.lds | 83 +++++++++++++++++++++++++++++++++++++ arch/x86/lib/efi/reloc_x86_64.c | 66 +++++++++++++++++++++++++++++ 2 files changed, 149 insertions(+) create mode 100644 arch/x86/cpu/efi/elf_x86_64_efi.lds create mode 100644 arch/x86/lib/efi/reloc_x86_64.c

diff --git a/arch/x86/cpu/efi/elf_x86_64_efi.lds b/arch/x86/cpu/efi/elf_x86_64_efi.lds new file mode 100644 index 0000000..9d9f057 --- /dev/null +++ b/arch/x86/cpu/efi/elf_x86_64_efi.lds @@ -0,0 +1,83 @@ +/* + * U-Boot EFI linker script + * + * SPDX-License-Identifier: BSD-2-Clause + * + * Modified from usr/lib32/elf_x86_64_efi.lds in gnu-efi + */ + +#include <config.h> + +OUTPUT_FORMAT("elf64-x86-64", "elf64-x86-64", "elf64-x86-64") +OUTPUT_ARCH(i386:x86-64) +ENTRY(_start) +SECTIONS +{ + image_base = .; + .hash : { *(.hash) } /* this MUST come first, EFI expects it */ + . = ALIGN(4096); + .eh_frame : { + *(.eh_frame) + } + + . = ALIGN(4096); + + .text : { + *(.text) + *(.text.*) + *(.gnu.linkonce.t.*) + } + + . = ALIGN(4096); + + .reloc : { + *(.reloc) + } + + . = ALIGN(4096); + + .data : { + *(.rodata*) + *(.got.plt) + *(.got) + *(.data*) + *(.sdata) + /* the EFI loader doesn't seem to like a .bss section, so we stick + * it all into .data: */ + *(.sbss) + *(.scommon) + *(.dynbss) + *(.bss) + *(COMMON) + *(.rel.local) + + /* U-Boot lists and device tree */ + . = ALIGN(8); + *(SORT(.u_boot_list*)); + . = ALIGN(8); + *(.dtb*); + } + + . = ALIGN(4096); + .dynamic : { *(.dynamic) } + . = ALIGN(4096); + + .rela : { + *(.rela.data*) + *(.rela.got) + *(.rela.stab) + } + + . = ALIGN(4096); + .dynsym : { *(.dynsym) } + . = ALIGN(4096); + .dynstr : { *(.dynstr) } + . = ALIGN(4096); + .ignored.reloc : { + *(.rela.reloc) + *(.eh_frame) + *(.note.GNU-stack) + } + + .comment 0 : { *(.comment) } +} diff --git a/arch/x86/lib/efi/reloc_x86_64.c b/arch/x86/lib/efi/reloc_x86_64.c new file mode 100644 index 0000000..5f71f2a --- /dev/null +++ b/arch/x86/lib/efi/reloc_x86_64.c @@ -0,0 +1,66 @@ +/* + * reloc_x86_64.c - position independent x86_64 ELF shared object relocator + * Copyright (C) 1999 Hewlett-Packard Co. + * Contributed by David Mosberger davidm@hpl.hp.com. + * Copyright (C) 2005 Intel Co. + * Contributed by Fenghua Yu fenghua.yu@intel.com. + * + * All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <common.h> +#include <efi.h> +#include <elf.h> +#include <asm/elf.h> + +efi_status_t _relocate(long ldbase, Elf64_Dyn *dyn, efi_handle_t image, + struct efi_system_table *systab) +{ + long relsz = 0, relent = 0; + Elf64_Rel *rel = 0; + unsigned long *addr; + int i; + + for (i = 0; dyn[i].d_tag != DT_NULL; ++i) { + switch (dyn[i].d_tag) { + case DT_RELA: + rel = (Elf64_Rel *) + ((unsigned long)dyn[i].d_un.d_ptr + ldbase); + break; + case DT_RELASZ: + relsz = dyn[i].d_un.d_val; + break; + case DT_RELAENT: + relent = dyn[i].d_un.d_val; + break; + default: + break; + } + } + + if (!rel && relent == 0) + return EFI_SUCCESS; + + if (!rel || relent == 0) + return EFI_LOAD_ERROR; + + while (relsz > 0) { + /* apply the relocs */ + switch (ELF64_R_TYPE(rel->r_info)) { + case R_X86_64_NONE: + break; + case R_X86_64_RELATIVE: + addr = (unsigned long *)(ldbase + rel->r_offset); + *addr += ldbase; + break; + default: + break; + } + rel = (Elf64_Rel *)((char *)rel + relent); + relsz -= relent; + } + + return EFI_SUCCESS; +}

It is useful to be able to load U-Boot onto a board even if is it already running EFI. This can allow access to the U-Boot command interface, flexible booting options and easier development.

The easiest way to do this is to build U-Boot as a binary blob and have an EFI stub copy it into RAM. Add support for this feature, targeting 32-bit initially.

Also add a way to detect when U-Boot has been loaded via a stub. This goes in common.h since it needs to be widely available so that we avoid redoing initialisation that should be skipped.

Signed-off-by: Simon Glass sjg@chromium.org Improvements to how the payload is built: Signed-off-by: Bin Meng bmeng.cn@gmail.com ---

Changes in v3: - Fix calling convention to starting U-Boot in the 32-bit stub - Rename LDFLAGS_EFI to LDFLAGS_EFI_PAYLOAD and move into this patch - Use quiet_cmd_xxx to link the payload

Changes in v2: - Add a comment as to why we must call exit_boot_services() twice - Drop \n\t at the end of a one-line asm statement - Merge in Bin's implementation of adding a U-Boot payload with objcopy - Remove comment about reset_cpu() returning to EFI in the stub - Rename CONFIG_ARCH_EFI to CONFIG_EFI_APP

Makefile | 24 +++++ arch/x86/config.mk | 7 ++ include/common.h | 7 ++ include/efi.h | 4 + lib/efi/Kconfig | 21 ++++ lib/efi/Makefile | 9 ++ lib/efi/efi_stub.c | 304 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 7 files changed, 376 insertions(+) create mode 100644 lib/efi/efi_stub.c

diff --git a/Makefile b/Makefile index 620c18f..752ee0d 100644 --- a/Makefile +++ b/Makefile @@ -755,6 +755,7 @@ ALL-$(CONFIG_SPL) += $(CONFIG_SPL_TARGET:"%"=%) endif ALL-$(CONFIG_REMAKE_ELF) += u-boot.elf ALL-$(CONFIG_EFI_APP) += u-boot-app.efi +ALL-$(CONFIG_EFI_STUB) += u-boot-payload.efi

ifneq ($(BUILD_ROM),) ALL-$(CONFIG_X86_RESET_VECTOR) += u-boot.rom @@ -790,6 +791,9 @@ cmd_objcopy = $(OBJCOPY) --gap-fill=0xff $(OBJCOPYFLAGS) \ quiet_cmd_zobjcopy = OBJCOPY $@ cmd_zobjcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@

+quiet_cmd_efipayload = OBJCOPY $@ +cmd_efipayload = $(OBJCOPY) -I binary -O $(EFIPAYLOAD_BFDTARGET) -B $(EFIPAYLOAD_BFDARCH) $< $@ + quiet_cmd_mkimage = MKIMAGE $@ cmd_mkimage = $(objtree)/tools/mkimage $(MKIMAGEFLAGS_$(@F)) -d $< $@ \ $(if $(KBUILD_VERBOSE:1=), >/dev/null) @@ -1087,6 +1091,26 @@ OBJCOPYFLAGS_u-boot-app.efi := $(OBJCOPYFLAGS_EFI) u-boot-app.efi: u-boot FORCE $(call if_changed,zobjcopy)

+u-boot-dtb.bin.o: u-boot-dtb.bin FORCE + $(call if_changed,efipayload) + +u-boot-payload.lds: $(LDSCRIPT_EFI) FORCE + $(call if_changed_dep,cpp_lds) + +# Rule to link the EFI payload which contains a stub and a U-Boot binary +quiet_cmd_u-boot_payload ?= LD $@ + cmd_u-boot_payload ?= $(LD) $(LDFLAGS_EFI_PAYLOAD) -o $@ \ + -T u-boot-payload.lds \ + lib/efi/efi.o lib/efi/efi_stub.o u-boot-dtb.bin.o \ + $(addprefix arch/$(ARCH)/lib/efi/,$(EFISTUB)) + +u-boot-payload: u-boot-dtb.bin.o u-boot-payload.lds FORCE + $(call if_changed,u-boot_payload) + +OBJCOPYFLAGS_u-boot-payload.efi := $(OBJCOPYFLAGS_EFI) +u-boot-payload.efi: u-boot-payload FORCE + $(call if_changed,zobjcopy) + u-boot-img.bin: spl/u-boot-spl.bin u-boot.img FORCE $(call if_changed,cat)

diff --git a/arch/x86/config.mk b/arch/x86/config.mk index e27f84a..334c10b 100644 --- a/arch/x86/config.mk +++ b/arch/x86/config.mk @@ -24,6 +24,10 @@ PLATFORM_LDFLAGS += -Bsymbolic -Bsymbolic-functions -m elf_i386 LDFLAGS_FINAL += --wrap=__divdi3 --wrap=__udivdi3 LDFLAGS_FINAL += --wrap=__moddi3 --wrap=__umoddi3

+# This is used in the top-level Makefile which does not include +# PLATFORM_LDFLAGS +LDFLAGS_EFI_PAYLOAD := -Bsymbolic -Bsymbolic-functions -shared --no-undefined + OBJCOPYFLAGS_EFI := -j .text -j .sdata -j .data -j .dynamic -j .dynsym \ -j .rel -j .rela -j .reloc

@@ -31,6 +35,9 @@ CFLAGS_NON_EFI := -mregparm=3 CFLAGS_EFI := -fpic -fshort-wchar

EFIARCH = ia32 +EFIPAYLOAD_BFDTARGET = elf32-i386 + +EFIPAYLOAD_BFDARCH = i386

LDSCRIPT_EFI := $(srctree)/$(CPUDIR)/efi/elf_$(EFIARCH)_efi.lds OBJCOPYFLAGS_EFI += --target=efi-app-$(EFIARCH) diff --git a/include/common.h b/include/common.h index 4566bd1..fcc9ae7 100644 --- a/include/common.h +++ b/include/common.h @@ -1021,6 +1021,13 @@ int cpu_release(int nr, int argc, char * const argv[]); offsetof(struct structure, member) == offset, \ "`struct " #structure "` offset for `" #member "` is not " #offset)

+/* Avoid using CONFIG_EFI_STUB directly as we may boot from other loaders */ +#ifdef CONFIG_EFI_STUB +#define ll_boot_init() false +#else +#define ll_boot_init() true +#endif + /* Pull in stuff for the build system */ #ifdef DO_DEPS_ONLY # include <environment.h> diff --git a/include/efi.h b/include/efi.h index f009701..1470c08 100644 --- a/include/efi.h +++ b/include/efi.h @@ -268,11 +268,15 @@ struct efi_priv { /* Base address of the EFI image */ extern char image_base[];

+/* Start and end of U-Boot image (for payload) */ +extern char _binary_u_boot_dtb_bin_start[], _binary_u_boot_dtb_bin_end[]; + /** * efi_get_sys_table() - Get access to the main EFI system table * * @return pointer to EFI system table */ + struct efi_system_table *efi_get_sys_table(void);

/** diff --git a/lib/efi/Kconfig b/lib/efi/Kconfig index b23ba5b..919e314 100644 --- a/lib/efi/Kconfig +++ b/lib/efi/Kconfig @@ -20,6 +20,11 @@ config EFI_APP command prompt and memory and I/O functions. Use 'reset' to return to EFI.

+config EFI_STUB + bool "Support running as an EFI payload" + +endchoice + config EFI_RAM_SIZE hex "Amount of EFI RAM for U-Boot" depends on EFI_APP @@ -30,4 +35,20 @@ config EFI_RAM_SIZE other smaller amounts) and it can never be increased after that. It is used as the RAM size in with U-Boot.

+choice + prompt "EFI 32/64-bit selection" + depends on EFI_STUB + help + EFI does not support mixing 32-bit and 64-bit modes. This is a + significant problem because it means that you must build a stub with + the correct type for EFI to load it correctly. If you are using + 32-bit EFI, select 32-bit here, else select 64-bit. Failure to do + this may produce no error message - it just won't start! + +config EFI_STUB_32BIT + bool "Produce a stub for running with 32-bit EFI" + +config EFI_STUB_64BIT + bool "Produce a stub for running with 64-bit EFI" + endchoice diff --git a/lib/efi/Makefile b/lib/efi/Makefile index 5ee344c..4bc67f0 100644 --- a/lib/efi/Makefile +++ b/lib/efi/Makefile @@ -5,3 +5,12 @@ #

obj-$(CONFIG_EFI_APP) += efi_app.o efi.o + +CFLAGS_REMOVE_efi_stub.o := -mregparm=3 \ + $(if $(CONFIG_EFI_STUB_64BIT),-march=i386 -m32) +CFLAGS_efi_stub.o := -fpic -fshort-wchar +CFLAGS_REMOVE_efi.o := -mregparm=3 \ + $(if $(CONFIG_EFI_STUB_64BIT),-march=i386 -m32) +CFLAGS_efi.o := -fpic -fshort-wchar + +extra-$(CONFIG_EFI_STUB) += efi_stub.o efi.o diff --git a/lib/efi/efi_stub.c b/lib/efi/efi_stub.c new file mode 100644 index 0000000..1e46f6e --- /dev/null +++ b/lib/efi/efi_stub.c @@ -0,0 +1,304 @@ +/* + * Copyright (c) 2015 Google, Inc + * + * SPDX-License-Identifier: GPL-2.0+ + * + * EFI information obtained here: + * http://wiki.phoenix.com/wiki/index.php/EFI_BOOT_SERVICES + * + * Loads a payload (U-Boot) within the EFI environment. This is built as a + * 32-bit EFI application. + */ + +#include <common.h> +#include <debug_uart.h> +#include <efi.h> +#include <efi_api.h> +#include <errno.h> +#include <ns16550.h> +#include <asm/cpu.h> +#include <asm/io.h> +#include <linux/err.h> +#include <linux/types.h> + +DECLARE_GLOBAL_DATA_PTR; + +#ifndef CONFIG_X86 +/* + * Problem areas: + * - putc() uses the ns16550 address directly and assumed I/O access. Many + * platforms will use memory access + * get_codeseg32() is only meaningful on x86 + */ +#error "This file needs to be ported for use on architectures" +#endif + +static struct efi_priv *global_priv; +static bool use_uart; + +struct __packed desctab_info { + uint16_t limit; + uint64_t addr; + uint16_t pad; +}; + +/* + * EFI uses Unicode and we don't. The easiest way to get a sensible output + * function is to use the U-Boot debug UART. We use EFI's console output + * function where available, and assume the built-in UART after that. We rely + * on EFI to set up the UART for us and just bring in the functions here. + * This last bit is a bit icky, but it's only for debugging anyway. We could + * build in ns16550.c with some effort, but this is a payload loader after + * all. + * + * Note: We avoid using printf() so we don't need to bring in lib/vsprintf.c. + * That would require some refactoring since we already build this for U-Boot. + * Building an EFI shared library version would have to be a separate stem. + * That might push us to using the SPL framework to build this stub. However + * that would involve a round of EFI-specific changes in SPL. Worth + * considering if we start needing more U-Boot functionality. Note that we + * could then move get_codeseg32() to arch/x86/cpu/cpu.c. + */ +void debug_uart_init(void) +{ +} + +void putc(const char ch) +{ + if (use_uart) { + NS16550_t com_port = (NS16550_t)0x3f8; + + while ((inb((ulong)&com_port->lsr) & UART_LSR_THRE) == 0) + ; + outb(ch, (ulong)&com_port->thr); + } else { + efi_putc(global_priv, ch); + } + if (ch == '\n') + putc('\r'); +} + +void puts(const char *str) +{ + while (*str) + putc(*str++); +} + +static void _debug_uart_putc(int ch) +{ + putc(ch); +} + +DEBUG_UART_FUNCS + +void *memcpy(void *dest, const void *src, size_t size) +{ + unsigned char *dptr = dest; + const unsigned char *ptr = src; + const unsigned char *end = src + size; + + while (ptr < end) + *dptr++ = *ptr++; + + return dest; +} + +void *memset(void *inptr, int ch, size_t size) +{ + char *ptr = inptr; + char *end = ptr + size; + + while (ptr < end) + *ptr++ = ch; + + return ptr; +} + +static void jump_to_uboot(ulong cs32, ulong addr, ulong info) +{ +#ifdef CONFIG_EFI_STUB_32BIT + /* + * U-Boot requires these parameters in registers, not on the stack. + * See _x86boot_start() for this code. + */ + typedef void (*func_t)(int bist, int unused, ulong info) + __attribute__((regparm(3))); + + ((func_t)addr)(0, 0, info); +#else + /* TODO: Implement this */ +#endif +} + +static void get_gdt(struct desctab_info *info) +{ + asm volatile ("sgdt %0" : : "m"(*info) : "memory"); +} + +static inline unsigned long read_cr3(void) +{ + unsigned long val; + + asm volatile("mov %%cr3,%0" : "=r" (val) : : "memory"); + return val; +} + +/** + * get_codeseg32() - Find the code segment to use for 32-bit code + * + * U-Boot only works in 32-bit mode at present, so when booting from 64-bit + * EFI we must first change to 32-bit mode. To do this we need to find the + * correct code segment to use (an entry in the Global Descriptor Table). + * + * @return code segment GDT offset, or 0 for 32-bit EFI, -ENOENT if not found + */ +static int get_codeseg32(void) +{ + int cs32 = 0; + + /* TODO(sjg): Implement this for 64-bit mode */ + return cs32; +} + +static int setup_info_table(struct efi_priv *priv, int size) +{ + struct efi_info_hdr *info; + efi_status_t ret; + + /* Get some memory for our info table */ + priv->info_size = size; + info = efi_malloc(priv, priv->info_size, &ret); + if (ret) { + printhex2(ret); + puts(" No memory for info table: "); + return ret; + } + + memset(info, '\0', sizeof(*info)); + info->version = EFI_TABLE_VERSION; + info->hdr_size = sizeof(*info); + priv->info = info; + priv->next_hdr = (char *)info + info->hdr_size; + + return 0; +} + +static void add_entry_addr(struct efi_priv *priv, enum efi_entry_t type, + void *ptr1, int size1, void *ptr2, int size2) +{ + struct efi_entry_hdr *hdr = priv->next_hdr; + + hdr->type = type; + hdr->size = size1 + size2; + hdr->addr = 0; + hdr->link = ALIGN(sizeof(*hdr) + hdr->size, 16); + priv->next_hdr += hdr->link; + memcpy(hdr + 1, ptr1, size1); + memcpy((void *)(hdr + 1) + size1, ptr2, size2); + priv->info->total_size = (ulong)priv->next_hdr - (ulong)priv->info; +} + +/** + * efi_main() - Start an EFI image + * + * This function is called by our EFI start-up code. It handles running + * U-Boot. If it returns, EFI will continue. + */ +efi_status_t efi_main(efi_handle_t image, struct efi_system_table *sys_table) +{ + struct efi_priv local_priv, *priv = &local_priv; + struct efi_boot_services *boot = sys_table->boottime; + struct efi_mem_desc *desc; + struct efi_entry_memmap map; + ulong key, desc_size, size; + efi_status_t ret; + u32 version; + int cs32; + + ret = efi_init(priv, "Payload", image, sys_table); + if (ret) { + printhex2(ret); puts(" efi_init() failed\n"); + return ret; + } + global_priv = priv; + + cs32 = get_codeseg32(); + if (cs32 < 0) + return EFI_UNSUPPORTED; + + /* Get the memory map so we can switch off EFI */ + size = 0; + ret = boot->get_memory_map(&size, NULL, &key, &desc_size, &version); + if (ret != EFI_BUFFER_TOO_SMALL) { + printhex2(BITS_PER_LONG); + printhex2(ret); + puts(" No memory map\n"); + return ret; + } + size += 1024; /* Since doing a malloc() may change the memory map! */ + desc = efi_malloc(priv, size, &ret); + if (!desc) { + printhex2(ret); + puts(" No memory for memory descriptor: "); + return ret; + } + ret = setup_info_table(priv, size + 128); + if (ret) + return ret; + + ret = boot->get_memory_map(&size, desc, &key, &desc_size, &version); + if (ret) { + printhex2(ret); + puts(" Can't get memory map\n"); + return ret; + } + + ret = boot->exit_boot_services(image, key); + if (ret) { + /* + * Unfortunately it happens that we cannot exit boot services + * the first time. But the second time it work. I don't know + * why but this seems to be a repeatable problem. To get + * around it, just try again. + */ + printhex2(ret); + puts(" Can't exit boot services\n"); + size = sizeof(desc); + ret = boot->get_memory_map(&size, desc, &key, &desc_size, + &version); + if (ret) { + printhex2(ret); + puts(" Can't get memory map\n"); + return ret; + } + ret = boot->exit_boot_services(image, key); + if (ret) { + printhex2(ret); + puts(" Can't exit boot services 2\n"); + return ret; + } + } + + map.version = version; + map.desc_size = desc_size; + add_entry_addr(priv, EFIET_MEMORY_MAP, &map, sizeof(map), desc, size); + add_entry_addr(priv, EFIET_END, NULL, 0, 0, 0); + + /* The EFI UART won't work now, switch to a debug one */ + use_uart = true; + + memcpy((void *)CONFIG_SYS_TEXT_BASE, _binary_u_boot_dtb_bin_start, + (ulong)_binary_u_boot_dtb_bin_end - + (ulong)_binary_u_boot_dtb_bin_start); + +#ifdef DEBUG + puts("EFI table at "); + printhex8((ulong)priv->info); + puts(" size "); + printhex8(priv->info->total_size); +#endif + putc('\n'); + jump_to_uboot(cs32, CONFIG_SYS_TEXT_BASE, (ulong)priv->info); + + return EFI_LOAD_ERROR; +}

Rather than add these as open-coded values, create an enum with the commonly used flags.

Signed-off-by: Simon Glass sjg@chromium.org Reviewed-by: Bin Meng bmeng.cn@gmail.com ---

Changes in v3: None Changes in v2: - Add descriptor bits for the base and limit - Rename GDT_4GB to GDT_4KB

arch/x86/include/asm/cpu.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+)

diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index 08284ee..5b89139 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -27,6 +27,24 @@ enum { X86_VENDOR_UNKNOWN = 0xff };

+/* Global descriptor table (GDT) bits */ +enum { + GDT_4KB = 1ULL << 55, + GDT_32BIT = 1ULL << 54, + GDT_LONG = 1ULL << 53, + GDT_PRESENT = 1ULL << 47, + GDT_NOTSYS = 1ULL << 44, + GDT_CODE = 1ULL << 43, + GDT_LIMIT_LOW_SHIFT = 0, + GDT_LIMIT_LOW_MASK = 0xffff, + GDT_LIMIT_HIGH_SHIFT = 48, + GDT_LIMIT_HIGH_MASK = 0xf, + GDT_BASE_LOW_SHIFT = 16, + GDT_BASE_LOW_MASK = 0xffff, + GDT_BASE_HIGH_SHIFT = 56, + GDT_BASE_HIGH_MASK = 0xf, +}; + struct cpuid_result { uint32_t eax; uint32_t ebx;

The procedure to drop from 64-bit mode to 32-bit is a bit messy. Add a function to take care of it. It requires identity-mapped pages and that the calling code is running below 4GB.

Signed-off-by: Simon Glass sjg@chromium.org Reviewed-by: Bin Meng bmeng.cn@gmail.com ---

Changes in v3: None Changes in v2: - Add a comment about the REX prefix - Drop the REX prefix in 32-bit mode

arch/x86/cpu/Makefile | 6 +++++ arch/x86/cpu/call32.S | 64 ++++++++++++++++++++++++++++++++++++++++++++++ arch/x86/include/asm/cpu.h | 9 +++++++ 3 files changed, 79 insertions(+) create mode 100644 arch/x86/cpu/call32.S

diff --git a/arch/x86/cpu/Makefile b/arch/x86/cpu/Makefile index 5e058c0..e797925 100644 --- a/arch/x86/cpu/Makefile +++ b/arch/x86/cpu/Makefile @@ -12,6 +12,12 @@ extra-y = start.o obj-$(CONFIG_X86_RESET_VECTOR) += resetvec.o start16.o obj-y += interrupts.o cpu.o cpu_x86.o call64.o

+AFLAGS_REMOVE_call32.o := -mregparm=3 \ + $(if $(CONFIG_EFI_STUB_64BIT),-march=i386 -m32) +AFLAGS_call32.o := -fpic -fshort-wchar + +extra-y += call32.o + obj-$(CONFIG_INTEL_BAYTRAIL) += baytrail/ obj-$(CONFIG_SYS_COREBOOT) += coreboot/ obj-$(CONFIG_EFI_APP) += efi/ diff --git a/arch/x86/cpu/call32.S b/arch/x86/cpu/call32.S new file mode 100644 index 0000000..c517e4a --- /dev/null +++ b/arch/x86/cpu/call32.S @@ -0,0 +1,64 @@ +/* + * (C) Copyright 2015 Google, Inc + * Written by Simon Glass sjg@chromium.org + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <asm/global_data.h> +#include <asm/msr-index.h> +#include <asm/processor-flags.h> + + /* + * rdi - 32-bit code segment selector + * rsi - target address + * rdx - table address (0 if none) + */ +.code64 +.globl cpu_call32 +cpu_call32: + cli + + /* Save table pointer */ + mov %edx, %ebx + + /* + * Debugging option, this outputs characters to the console UART + * mov $0x3f8,%edx + * mov $'a',%al + * out %al,(%dx) + */ + + pushf + push %rdi /* 32-bit code segment */ + lea compat(%rip), %rax + push %rax + .byte 0x48 /* REX prefix to force 64-bit far return */ + retf +.code32 +compat: + /* + * We are now in compatibility mode with a default operand size of + * 32 bits. First disable paging. + */ + movl %cr0, %eax + andl $~X86_CR0_PG, %eax + movl %eax, %cr0 + + /* Invalidate TLB */ + xorl %eax, %eax + movl %eax, %cr3 + + /* Disable Long mode in EFER (Extended Feature Enable Register) */ + movl $MSR_EFER, %ecx + rdmsr + btr $_EFER_LME, %eax + wrmsr + + /* Set up table pointer for _x86boot_start */ + mov %ebx, %ecx + + /* Jump to the required target */ + pushl %edi /* 32-bit code segment */ + pushl %esi /* 32-bit target address */ + retf diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index 5b89139..c70183c 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -230,6 +230,15 @@ char *cpu_get_name(char *name); void cpu_call64(ulong pgtable, ulong setup_base, ulong target);

/** + * cpu_call32() - Jump to a 32-bit entry point + * + * @code_seg32: 32-bit code segment to use (GDT offset, e.g. 0x20) + * @target: Pointer to the start of the 32-bit U-Boot image/entry point + * @table: Pointer to start of info table to pass to U-Boot + */ +void cpu_call32(ulong code_seg32, ulong target, ulong table); + +/** * cpu_jump_to_64bit() - Jump to a 64-bit Linux kernel * * The kernel is uncompressed and the 64-bit entry point is expected to be

Most EFI implementations use 64-bit. Add a way to build U-Boot as a 64-bit EFI payload. The payload unpacks a (32-bit) U-Boot and starts it. This can be enabled for x86 boards at present.

Signed-off-by: Simon Glass sjg@chromium.org Improvements to how the payload is built: Signed-off-by: Bin Meng bmeng.cn@gmail.com ---

Changes in v3: - Add spaces around EFIARCH= - Use CONFIG_SYS_MONITOR_LEN as a more accurate value for U-Boot's size

Changes in v2: - Add -no-red-zone for 64-bit only - Check the GDT selector's base and limit against the target address - Drop use of CONFIG_X86_64 since we don't support a 64-bit EFI application yet - Merge in Bin's implementation of adding a U-Boot payload with objcopy - Move the 64-bit crt and reloc code into this patch - Move the 64-bit efi.h additions into this patch - Rename GDT_4GB to GDT_4KB

Makefile | 2 +- arch/x86/config.mk | 10 ++++++ arch/x86/include/asm/types.h | 5 ++- arch/x86/lib/efi/crt0-efi-x86_64.S | 51 ++++++++++++++++++++++++++ include/efi.h | 7 ++++ lib/efi/efi_stub.c | 74 +++++++++++++++++++++++++++++++++++--- 6 files changed, 143 insertions(+), 6 deletions(-) create mode 100644 arch/x86/lib/efi/crt0-efi-x86_64.S

diff --git a/Makefile b/Makefile index 752ee0d..bb0ba9f 100644 --- a/Makefile +++ b/Makefile @@ -1100,7 +1100,7 @@ u-boot-payload.lds: $(LDSCRIPT_EFI) FORCE # Rule to link the EFI payload which contains a stub and a U-Boot binary quiet_cmd_u-boot_payload ?= LD $@ cmd_u-boot_payload ?= $(LD) $(LDFLAGS_EFI_PAYLOAD) -o $@ \ - -T u-boot-payload.lds \ + -T u-boot-payload.lds arch/x86/cpu/call32.o \ lib/efi/efi.o lib/efi/efi_stub.o u-boot-dtb.bin.o \ $(addprefix arch/$(ARCH)/lib/efi/,$(EFISTUB))

diff --git a/arch/x86/config.mk b/arch/x86/config.mk index 334c10b..d7addd8 100644 --- a/arch/x86/config.mk +++ b/arch/x86/config.mk @@ -34,14 +34,24 @@ OBJCOPYFLAGS_EFI := -j .text -j .sdata -j .data -j .dynamic -j .dynsym \ CFLAGS_NON_EFI := -mregparm=3 CFLAGS_EFI := -fpic -fshort-wchar

+ifeq ($(CONFIG_EFI_STUB_64BIT),) +CFLAGS_EFI += $(call cc-option, -mno-red-zone) EFIARCH = ia32 EFIPAYLOAD_BFDTARGET = elf32-i386 +else +EFIARCH = x86_64 +EFIPAYLOAD_BFDTARGET = elf64-x86-64 +endif

EFIPAYLOAD_BFDARCH = i386

LDSCRIPT_EFI := $(srctree)/$(CPUDIR)/efi/elf_$(EFIARCH)_efi.lds +EFISTUB := crt0-efi-$(EFIARCH).o reloc_$(EFIARCH).o OBJCOPYFLAGS_EFI += --target=efi-app-$(EFIARCH)

+CPPFLAGS_REMOVE_crt0-efi-$(EFIARCH).o += $(CFLAGS_NON_EFI) +CPPFLAGS_crt0-efi-$(EFIARCH).o += $(CFLAGS_EFI) + ifeq ($(CONFIG_EFI_APP),y)

PLATFORM_CPPFLAGS += $(CFLAGS_EFI) diff --git a/arch/x86/include/asm/types.h b/arch/x86/include/asm/types.h index e272c90..766617f 100644 --- a/arch/x86/include/asm/types.h +++ b/arch/x86/include/asm/types.h @@ -44,8 +44,11 @@ typedef __INT64_TYPE__ s64; typedef __UINT64_TYPE__ u64; #endif

+#ifdef CONFIG_EFI_STUB_64BIT +#define BITS_PER_LONG 64 +#else #define BITS_PER_LONG 32 - +#endif /* Dma addresses are 32-bits wide. */

typedef u32 dma_addr_t; diff --git a/arch/x86/lib/efi/crt0-efi-x86_64.S b/arch/x86/lib/efi/crt0-efi-x86_64.S new file mode 100644 index 0000000..c5cbf41 --- /dev/null +++ b/arch/x86/lib/efi/crt0-efi-x86_64.S @@ -0,0 +1,51 @@ +/* + * crt0-efi-x86_64.S - x86_64 EFI startup code. + * Copyright (C) 1999 Hewlett-Packard Co. + * Contributed by David Mosberger davidm@hpl.hp.com. + * Copyright (C) 2005 Intel Co. + * Contributed by Fenghua Yu fenghua.yu@intel.com. + * + * All rights reserved. + * SPDX-License-Identifier: BSD-3-Clause + */ + .text + .align 4 + + .globl _start +_start: + subq $8, %rsp + pushq %rcx + pushq %rdx + +0: + lea image_base(%rip), %rdi + lea _DYNAMIC(%rip), %rsi + + popq %rcx + popq %rdx + pushq %rcx + pushq %rdx + call _relocate + + popq %rdi + popq %rsi + + call efi_main + addq $8, %rsp + +.exit: + ret + + /* + * hand-craft a dummy .reloc section so EFI knows it's a relocatable + * executable: + */ + .data +dummy: .long 0 + +#define IMAGE_REL_ABSOLUTE 0 + .section .reloc, "a" +label1: + .long dummy-label1 /* Page RVA */ + .long 10 /* Block Size (2*4+2) */ + .word (IMAGE_REL_ABSOLUTE << 12) + 0 /* reloc for dummy */ diff --git a/include/efi.h b/include/efi.h index 1470c08..fcafda0 100644 --- a/include/efi.h +++ b/include/efi.h @@ -18,6 +18,13 @@ #include <linux/string.h> #include <linux/types.h>

+#ifdef CONFIG_EFI_STUB_64BIT +/* EFI uses the Microsoft ABI which is not the default for GCC */ +#define EFIAPI __attribute__((ms_abi)) +#else +#define EFIAPI +#endif + struct efi_device_path;

#define EFI_SUCCESS 0 diff --git a/lib/efi/efi_stub.c b/lib/efi/efi_stub.c index 1e46f6e..d4d3e49 100644 --- a/lib/efi/efi_stub.c +++ b/lib/efi/efi_stub.c @@ -6,8 +6,8 @@ * EFI information obtained here: * http://wiki.phoenix.com/wiki/index.php/EFI_BOOT_SERVICES * - * Loads a payload (U-Boot) within the EFI environment. This is built as a - * 32-bit EFI application. + * Loads a payload (U-Boot) within the EFI environment. This is built as an + * EFI application. It can be built either in 32-bit or 64-bit mode. */

#include <common.h> @@ -126,14 +126,16 @@ static void jump_to_uboot(ulong cs32, ulong addr, ulong info)

((func_t)addr)(0, 0, info); #else - /* TODO: Implement this */ + cpu_call32(cs32, CONFIG_SYS_TEXT_BASE, info); #endif }

+#ifdef CONFIG_EFI_STUB_64BIT static void get_gdt(struct desctab_info *info) { asm volatile ("sgdt %0" : : "m"(*info) : "memory"); } +#endif

static inline unsigned long read_cr3(void) { @@ -156,7 +158,71 @@ static int get_codeseg32(void) { int cs32 = 0;

- /* TODO(sjg): Implement this for 64-bit mode */ +#ifdef CONFIG_EFI_STUB_64BIT + struct desctab_info gdt; + uint64_t *ptr; + int i; + + get_gdt(&gdt); + for (ptr = (uint64_t *)(unsigned long)gdt.addr, i = 0; i < gdt.limit; + i += 8, ptr++) { + uint64_t desc = *ptr; + uint64_t base, limit; + + /* + * Check that the target U-Boot jump address is within the + * selector and that the selector is of the right type. + */ + base = ((desc >> GDT_BASE_LOW_SHIFT) & GDT_BASE_LOW_MASK) | + ((desc >> GDT_BASE_HIGH_SHIFT) & GDT_BASE_HIGH_MASK) + << 16; + limit = ((desc >> GDT_LIMIT_LOW_SHIFT) & GDT_LIMIT_LOW_MASK) | + ((desc >> GDT_LIMIT_HIGH_SHIFT) & GDT_LIMIT_HIGH_MASK) + << 16; + base <<= 12; /* 4KB granularity */ + limit <<= 12; + if ((desc & GDT_PRESENT) && (desc && GDT_NOTSYS) && + !(desc & GDT_LONG) && (desc & GDT_4KB) && + (desc & GDT_32BIT) && (desc & GDT_CODE) && + CONFIG_SYS_TEXT_BASE > base && + CONFIG_SYS_TEXT_BASE + CONFIG_SYS_MONITOR_LEN < limit + ) { + cs32 = i; + break; + } + } + +#ifdef DEBUG + puts("\ngdt: "); + printhex8(gdt.limit); + puts(", addr: "); + printhex8(gdt.addr >> 32); + printhex8(gdt.addr); + for (i = 0; i < gdt.limit; i += 8) { + uint32_t *ptr = (uint32_t *)((unsigned long)gdt.addr + i); + + puts("\n"); + printhex2(i); + puts(": "); + printhex8(ptr[1]); + puts(" "); + printhex8(ptr[0]); + } + puts("\n "); + puts("32-bit code segment: "); + printhex2(cs32); + puts("\n "); + + puts("page_table: "); + printhex8(read_cr3()); + puts("\n "); +#endif + if (!cs32) { + puts("Can't find 32-bit code segment\n"); + return -ENOENT; + } +#endif + return cs32; }

We cannot use this driver when running from EFI as we have no direct hardware access. In fact coreboot uses a different driver which uses tables provided by coreboot. So far it does not seem possible to use a normal video driver when booting from EFI.

Signed-off-by: Simon Glass sjg@chromium.org Acked-by: Anatolij Gustschin agust@denx.de Reviewed-by: Bin Meng bmeng.cn@gmail.com ---

Changes in v3: None Changes in v2: - Replace 'Coreboot' with 'coreboot'

drivers/video/vesa_fb.c | 8 ++++++++ 1 file changed, 8 insertions(+)

diff --git a/drivers/video/vesa_fb.c b/drivers/video/vesa_fb.c index 909f8e8..4e6d070 100644 --- a/drivers/video/vesa_fb.c +++ b/drivers/video/vesa_fb.c @@ -24,6 +24,14 @@ void *video_hw_init(void) int ret;

printf("Video: "); + if (!ll_boot_init()) { + /* + * If we are running from EFI or coreboot, this driver can't + * work. + */ + printf("Not available (previous bootloader prevents it)\n"); + return NULL; + } if (vbe_get_video_info(gdev)) { dev = pci_find_class(PCI_CLASS_DISPLAY_VGA << 8, 0); if (dev == -1) {

Add some documentation on the EFI implementation in U-Boot.

Signed-off-by: Ben Stoltz stoltz@google.com Signed-off-by: Simon Glass sjg@chromium.org Reviewed-by: Bin Meng bmeng.cn@gmail.com ---

Changes in v3: None Changes in v2: - Drop patch "Add a link script entry for U-Boot as a payload" - Replace 'Coreboot' with 'coreboot' - Use CONFIG_EFI_APP instead of CONFIG_ARCH_EFI - Use u-boot-app.efi instead of u-boot.efi

doc/README.efi | 237 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 237 insertions(+) create mode 100644 doc/README.efi

diff --git a/doc/README.efi b/doc/README.efi new file mode 100644 index 0000000..7c95579 --- /dev/null +++ b/doc/README.efi @@ -0,0 +1,237 @@ +# +# Copyright (C) 2015 Google, Inc +# +# SPDX-License-Identifier: GPL-2.0+ +# + +U-Boot on EFI +============= +This document provides information about U-Boot running on top of EFI, either +as an application or just as a means of getting U-Boot onto a new platform. + + +In God's Name, Why? +------------------- +This is useful in several situations: + +- You have EFI running on a board but U-Boot does not natively support it +fully yet. You can boot into U-Boot from EFI and use that until U-Boot is +fully ported + +- You need to use an EFI implementation (e.g. UEFI) because your vendor +requires it in order to provide support + +- You plan to use coreboot to boot into U-Boot but coreboot support does +not currently exist for your platform. In the meantime you can use U-Boot +on EFI and then move to U-Boot on coreboot when ready + +- You use EFI but want to experiment with a simpler alternative like U-Boot + + +Status +------ +Only x86 is supported at present. If you are using EFI on another architecture +you may want to reconsider. However, much of the code is generic so could be +ported. + +U-Boot supports running as an EFI application for 32-bit EFI only. This is +not very useful since only a serial port is provided. You can look around at +memory and type 'help' but that is about it. + +More usefully, U-Boot supports building itself as a payload for either 32-bit +or 64-bit EFI. U-Boot is packaged up and loaded in its entirety by EFI. Once +started, U-Boot changes to 32-bit mode (currently) and takes over the +machine. You can use devices, boot a kernel, etc. + + +Build Instructions +------------------ +First choose a board that has EFI support and obtain an EFI implementation +for that board. It will be either 32-bit or 64-bit. + +To build U-Boot as an EFI application (32-bit EFI required), enable +CONFIG_EFI and CONFIG_EFI_APP. The efi-x86 config is set up for this. + +To build U-Boot as an EFI payload (32-bit or 64-bit EFI can be used), adjust +an existing config to enable CONFIG_EFI, CONFIG_EFI_STUB and either +CONFIG_EFI_STUB_32BIT or CONFIG_EFI_STUB_64BIT. + +Then build U-Boot as normal, e.g. + + make qemu-x86_defconfig + make menuconfig (or make xconfig if you prefer) + # change the settings as above + make + +You will end up with one of these files: + + u-boot-app.efi - U-Boot EFI application + u-boot-payload.efi - U-Boot EFI payload application + + +Trying it out +------------- +Qemu is an emulator and it can emulate an x86 machine. You can run the +payload with something like this: + + mkdir /tmp/efi + cp /path/to/u-boot*.efi /tmp/efi + qemu-system-x86_64 -bios bios.bin -hda fat:/tmp/efi/ + +Add -nographic if you want to use the terminal for output. Once it starts +type 'fs0:u-boot-payload.efi' to run the payload or 'fs0:u-boot-app.efi' to +run the application. 'bios.bin' is the EFI 'BIOS'. + +To try it on real hardware, put u-boot-app.efi on a suitable boot medium, +such as a USB stick. Then you can type something like this to start it: + + fs0:u-boot-payload.efi + +(or fs0:u-boot-app.efi for the application) + +This will start the payload, copy U-Boot into RAM and start U-Boot. Note +that EFI does not support booting a 64-bit application from a 32-bit +EFI (or vice versa). Also it will often fail to print an error message if +you get this wrong. + + +Inner workings +============== +Here follow a few implementation notes for those who want to fiddle with +this and perhaps contribute patches. + +The application and payload approaches sound similar but are in fact +implemented completely differently. + +EFI Application +--------------- +For the application the whole of U-Boot is built as a shared library. The +efi_main() function is in lib/efi/efi_app.c. It sets up some basic EFI +functions with efi_init(), sets up U-Boot global_data, allocates memory for +U-Boot's malloc(), etc. and enters the normal init sequence (board_init_f() +and board_init_r()). + +Since U-Boot limits its memory access to the allocated regions very little +special code is needed. The CONFIG_EFI_APP option controls a few things +that need to change so 'git grep CONFIG_EFI_APP' may be instructive. +The CONFIG_EFI option controls more general EFI adjustments. + +The only available driver is the serial driver. This calls back into EFI +'boot services' to send and receive characters. Although it is implemented +as a serial driver the console device is not necessarilly serial. If you +boot EFI with video output then the 'serial' device will operate on your +target devices's display instead and the device's USB keyboard will also +work if connected. If you have both serial and video output, then both +consoles will be active. Even though U-Boot does the same thing normally, +These are features of EFI, not U-Boot. + +Very little code is involved in implementing the EFI application feature. +U-Boot is highly portable. Most of the difficulty is in modifying the +Makefile settings to pass the right build flags. In particular there is very +little x86-specific code involved - you can find most of it in +arch/x86/cpu. Porting to ARM (which can also use EFI if you are brave +enough) should be straightforward. + +Use the 'reset' command to get back to EFI. + +EFI Payload +----------- +The payload approach is a different kettle of fish. It works by building +U-Boot exactly as normal for your target board, then adding the entire +image (including device tree) into a small EFI stub application responsible +for booting it. The stub application is built as a normal EFI application +except that it has a lot of data attached to it. + +The stub application is implemented in lib/efi/efi_stub.c. The efi_main() +function is called by EFI. It is responsible for copying U-Boot from its +original location into memory, disabling EFI boot services and starting +U-Boot. U-Boot then starts as normal, relocates, starts all drivers, etc. + +The stub application is architecture-dependent. At present it has some +x86-specific code and a comment at the top of efi_stub.c describes this. + +While the stub application does allocate some memory from EFI this is not +used by U-Boot (the payload). In fact when U-Boot starts it has all of the +memory available to it and can operate as it pleases (but see the next +section). + +Tables +------ +The payload can pass information to U-Boot in the form of EFI tables. At +present this feature is used to pass the EFI memory map, an inordinately +large list of memory regions. You can use the 'efi mem all' command to +display this list. U-Boot uses the list to work out where to relocate +itself. + +Although U-Boot can use any memory it likes, EFI marks some memory as used +by 'run-time services', code that hangs around while U-Boot is running and +is even present when Linux is running. This is common on x86 and provides +a way for Linux to call back into the firmware to control things like CPU +fan speed. U-Boot uses only 'conventional' memory, in EFI terminology. It +will relocate itself to the top of the largest block of memory it can find +below 4GB. + +Interrupts +---------- +U-Boot drivers typically don't use interrupts. Since EFI enables interrupts +it is possible that an interrupt will fire that U-Boot cannot handle. This +seems to cause problems. For this reason the U-Boot payload runs with +interrupts disabled at present. + +32/64-bit +--------- +While the EFI application can in principle be built as either 32- or 64-bit, +only 32-bit is currently supported. This means that the application can only +be used with 32-bit EFI. + +The payload stub can be build as either 32- or 64-bits. Only a small amount +of code is built this way (see the extra- line in lib/efi/Makefile). +Everything else is built as a normal U-Boot, so is always 32-bit on x86 at +present. + +Future work +----------- +This work could be extended in a number of ways: + +- Add a generic x86 EFI payload configuration. At present you need to modify +an existing one, but mostly the low-level x86 code is disabled when booting +on EFI anyway, so a generic 'EFI' board could be created with a suitable set +of drivers enabled. + +- Add ARM support + +- Add 64-bit application support + +- Figure out how to solve the interrupt problem + +- Add more drivers to the application side (e.g. video, block devices, USB, +environment access). This would mostly be an academic exercise as a strong +use case is not readily apparent, but it might be fun. + +- Avoid turning off boot services in the stub. Instead allow U-Boot to make +use of boot services in case it wants to. It is unclear what it might want +though. + +Where is the code? +------------------ +lib/efi + payload stub, application, support code. Mostly arch-neutral + +arch/x86/lib/efi + helper functions for the fake DRAM init, etc. These can be used by + any board that runs as a payload. + +arch/x86/cpu/efi + x86 support code for running as an EFI application + +board/efi/efi-x86/efi.c + x86 board code for running as an EFI application + +common/cmd_efi.c + the 'efi' command + + +-- +Ben Stoltz, Simon Glass +Google, Inc +July 2015

This was missed in the patch 'Add a way to skip relocation'. Add it in now.

I hope to squash this patch into the earlier one before sending to mainline.

Signed-off-by: Simon Glass sjg@chromium.org ---

Changes in v3: - Add new patch to allow device tree relocation to be disabled

Changes in v2: None

common/board_f.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/common/board_f.c b/common/board_f.c index c596083..c7cc67c 100644 --- a/common/board_f.c +++ b/common/board_f.c @@ -654,6 +654,8 @@ static int setup_dram_config(void)

static int reloc_fdt(void) { + if (gd->flags & GD_FLG_SKIP_RELOC) + return 0; if (gd->new_fdt) { memcpy(gd->new_fdt, gd->fdt_blob, gd->fdt_size); gd->fdt_blob = gd->new_fdt;