mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-10 15:14:43 +00:00
efi: Add support for loading U-Boot through an EFI stub
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> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
This commit is contained in:
Simon Glass
parent
465a67cf52
commit
476476e73b
7 changed files with 376 additions and 0 deletions
24
Makefile
24
Makefile
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@ -755,6 +755,7 @@ ALL-$(CONFIG_SPL) += $(CONFIG_SPL_TARGET:"%"=%)
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endif
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ALL-$(CONFIG_REMAKE_ELF) += u-boot.elf
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ALL-$(CONFIG_EFI_APP) += u-boot-app.efi
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ALL-$(CONFIG_EFI_STUB) += u-boot-payload.efi
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ifneq ($(BUILD_ROM),)
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ALL-$(CONFIG_X86_RESET_VECTOR) += u-boot.rom
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@ -790,6 +791,9 @@ cmd_objcopy = $(OBJCOPY) --gap-fill=0xff $(OBJCOPYFLAGS) \
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quiet_cmd_zobjcopy = OBJCOPY $@
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cmd_zobjcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
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quiet_cmd_efipayload = OBJCOPY $@
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cmd_efipayload = $(OBJCOPY) -I binary -O $(EFIPAYLOAD_BFDTARGET) -B $(EFIPAYLOAD_BFDARCH) $< $@
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quiet_cmd_mkimage = MKIMAGE $@
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cmd_mkimage = $(objtree)/tools/mkimage $(MKIMAGEFLAGS_$(@F)) -d $< $@ \
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$(if $(KBUILD_VERBOSE:1=), >/dev/null)
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@ -1087,6 +1091,26 @@ OBJCOPYFLAGS_u-boot-app.efi := $(OBJCOPYFLAGS_EFI)
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u-boot-app.efi: u-boot FORCE
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$(call if_changed,zobjcopy)
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u-boot-dtb.bin.o: u-boot-dtb.bin FORCE
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$(call if_changed,efipayload)
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u-boot-payload.lds: $(LDSCRIPT_EFI) FORCE
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$(call if_changed_dep,cpp_lds)
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# Rule to link the EFI payload which contains a stub and a U-Boot binary
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quiet_cmd_u-boot_payload ?= LD $@
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cmd_u-boot_payload ?= $(LD) $(LDFLAGS_EFI_PAYLOAD) -o $@ \
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-T u-boot-payload.lds \
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lib/efi/efi.o lib/efi/efi_stub.o u-boot-dtb.bin.o \
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$(addprefix arch/$(ARCH)/lib/efi/,$(EFISTUB))
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u-boot-payload: u-boot-dtb.bin.o u-boot-payload.lds FORCE
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$(call if_changed,u-boot_payload)
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OBJCOPYFLAGS_u-boot-payload.efi := $(OBJCOPYFLAGS_EFI)
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u-boot-payload.efi: u-boot-payload FORCE
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$(call if_changed,zobjcopy)
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u-boot-img.bin: spl/u-boot-spl.bin u-boot.img FORCE
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$(call if_changed,cat)
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@ -24,6 +24,10 @@ PLATFORM_LDFLAGS += -Bsymbolic -Bsymbolic-functions -m elf_i386
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LDFLAGS_FINAL += --wrap=__divdi3 --wrap=__udivdi3
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LDFLAGS_FINAL += --wrap=__moddi3 --wrap=__umoddi3
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# This is used in the top-level Makefile which does not include
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# PLATFORM_LDFLAGS
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LDFLAGS_EFI_PAYLOAD := -Bsymbolic -Bsymbolic-functions -shared --no-undefined
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OBJCOPYFLAGS_EFI := -j .text -j .sdata -j .data -j .dynamic -j .dynsym \
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-j .rel -j .rela -j .reloc
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@ -31,6 +35,9 @@ CFLAGS_NON_EFI := -mregparm=3
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CFLAGS_EFI := -fpic -fshort-wchar
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EFIARCH = ia32
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EFIPAYLOAD_BFDTARGET = elf32-i386
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EFIPAYLOAD_BFDARCH = i386
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LDSCRIPT_EFI := $(srctree)/$(CPUDIR)/efi/elf_$(EFIARCH)_efi.lds
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OBJCOPYFLAGS_EFI += --target=efi-app-$(EFIARCH)
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@ -1021,6 +1021,13 @@ int cpu_release(int nr, int argc, char * const argv[]);
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offsetof(struct structure, member) == offset, \
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"`struct " #structure "` offset for `" #member "` is not " #offset)
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/* Avoid using CONFIG_EFI_STUB directly as we may boot from other loaders */
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#ifdef CONFIG_EFI_STUB
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#define ll_boot_init() false
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#else
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#define ll_boot_init() true
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#endif
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/* Pull in stuff for the build system */
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#ifdef DO_DEPS_ONLY
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# include <environment.h>
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@ -268,11 +268,15 @@ struct efi_priv {
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/* Base address of the EFI image */
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extern char image_base[];
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/* Start and end of U-Boot image (for payload) */
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extern char _binary_u_boot_dtb_bin_start[], _binary_u_boot_dtb_bin_end[];
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/**
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* efi_get_sys_table() - Get access to the main EFI system table
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*
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* @return pointer to EFI system table
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*/
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struct efi_system_table *efi_get_sys_table(void);
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/**
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@ -20,6 +20,11 @@ config EFI_APP
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command prompt and memory and I/O functions. Use 'reset' to return
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to EFI.
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config EFI_STUB
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bool "Support running as an EFI payload"
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endchoice
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config EFI_RAM_SIZE
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hex "Amount of EFI RAM for U-Boot"
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depends on EFI_APP
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@ -30,4 +35,20 @@ config EFI_RAM_SIZE
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other smaller amounts) and it can never be increased after that.
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It is used as the RAM size in with U-Boot.
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choice
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prompt "EFI 32/64-bit selection"
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depends on EFI_STUB
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help
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EFI does not support mixing 32-bit and 64-bit modes. This is a
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significant problem because it means that you must build a stub with
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the correct type for EFI to load it correctly. If you are using
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32-bit EFI, select 32-bit here, else select 64-bit. Failure to do
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this may produce no error message - it just won't start!
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config EFI_STUB_32BIT
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bool "Produce a stub for running with 32-bit EFI"
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config EFI_STUB_64BIT
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bool "Produce a stub for running with 64-bit EFI"
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endchoice
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@ -5,3 +5,12 @@
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#
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obj-$(CONFIG_EFI_APP) += efi_app.o efi.o
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CFLAGS_REMOVE_efi_stub.o := -mregparm=3 \
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$(if $(CONFIG_EFI_STUB_64BIT),-march=i386 -m32)
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CFLAGS_efi_stub.o := -fpic -fshort-wchar
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CFLAGS_REMOVE_efi.o := -mregparm=3 \
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$(if $(CONFIG_EFI_STUB_64BIT),-march=i386 -m32)
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CFLAGS_efi.o := -fpic -fshort-wchar
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extra-$(CONFIG_EFI_STUB) += efi_stub.o efi.o
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304
lib/efi/efi_stub.c
Normal file
304
lib/efi/efi_stub.c
Normal file
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@ -0,0 +1,304 @@
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/*
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* Copyright (c) 2015 Google, Inc
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*
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* SPDX-License-Identifier: GPL-2.0+
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*
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* EFI information obtained here:
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* http://wiki.phoenix.com/wiki/index.php/EFI_BOOT_SERVICES
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*
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* Loads a payload (U-Boot) within the EFI environment. This is built as a
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* 32-bit EFI application.
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*/
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#include <common.h>
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#include <debug_uart.h>
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#include <efi.h>
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#include <efi_api.h>
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#include <errno.h>
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#include <ns16550.h>
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#include <asm/cpu.h>
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#include <asm/io.h>
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#include <linux/err.h>
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#include <linux/types.h>
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DECLARE_GLOBAL_DATA_PTR;
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#ifndef CONFIG_X86
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/*
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* Problem areas:
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* - putc() uses the ns16550 address directly and assumed I/O access. Many
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* platforms will use memory access
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* get_codeseg32() is only meaningful on x86
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*/
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#error "This file needs to be ported for use on architectures"
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#endif
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static struct efi_priv *global_priv;
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static bool use_uart;
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struct __packed desctab_info {
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uint16_t limit;
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uint64_t addr;
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uint16_t pad;
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};
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/*
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* EFI uses Unicode and we don't. The easiest way to get a sensible output
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* function is to use the U-Boot debug UART. We use EFI's console output
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* function where available, and assume the built-in UART after that. We rely
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* on EFI to set up the UART for us and just bring in the functions here.
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* This last bit is a bit icky, but it's only for debugging anyway. We could
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* build in ns16550.c with some effort, but this is a payload loader after
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* all.
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*
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* Note: We avoid using printf() so we don't need to bring in lib/vsprintf.c.
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* That would require some refactoring since we already build this for U-Boot.
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* Building an EFI shared library version would have to be a separate stem.
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* That might push us to using the SPL framework to build this stub. However
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* that would involve a round of EFI-specific changes in SPL. Worth
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* considering if we start needing more U-Boot functionality. Note that we
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* could then move get_codeseg32() to arch/x86/cpu/cpu.c.
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*/
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void debug_uart_init(void)
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{
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}
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void putc(const char ch)
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{
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if (use_uart) {
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NS16550_t com_port = (NS16550_t)0x3f8;
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while ((inb((ulong)&com_port->lsr) & UART_LSR_THRE) == 0)
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;
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outb(ch, (ulong)&com_port->thr);
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} else {
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efi_putc(global_priv, ch);
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}
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if (ch == '\n')
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putc('\r');
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}
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void puts(const char *str)
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{
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while (*str)
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putc(*str++);
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}
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static void _debug_uart_putc(int ch)
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{
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putc(ch);
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}
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DEBUG_UART_FUNCS
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void *memcpy(void *dest, const void *src, size_t size)
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{
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unsigned char *dptr = dest;
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const unsigned char *ptr = src;
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const unsigned char *end = src + size;
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while (ptr < end)
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*dptr++ = *ptr++;
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return dest;
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}
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void *memset(void *inptr, int ch, size_t size)
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{
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char *ptr = inptr;
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char *end = ptr + size;
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while (ptr < end)
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*ptr++ = ch;
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return ptr;
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}
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static void jump_to_uboot(ulong cs32, ulong addr, ulong info)
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{
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#ifdef CONFIG_EFI_STUB_32BIT
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/*
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* U-Boot requires these parameters in registers, not on the stack.
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* See _x86boot_start() for this code.
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*/
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typedef void (*func_t)(int bist, int unused, ulong info)
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__attribute__((regparm(3)));
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((func_t)addr)(0, 0, info);
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#else
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/* TODO: Implement this */
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#endif
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}
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static void get_gdt(struct desctab_info *info)
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{
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asm volatile ("sgdt %0" : : "m"(*info) : "memory");
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}
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static inline unsigned long read_cr3(void)
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{
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unsigned long val;
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asm volatile("mov %%cr3,%0" : "=r" (val) : : "memory");
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return val;
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}
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/**
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* get_codeseg32() - Find the code segment to use for 32-bit code
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*
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* U-Boot only works in 32-bit mode at present, so when booting from 64-bit
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* EFI we must first change to 32-bit mode. To do this we need to find the
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* correct code segment to use (an entry in the Global Descriptor Table).
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*
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* @return code segment GDT offset, or 0 for 32-bit EFI, -ENOENT if not found
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*/
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static int get_codeseg32(void)
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{
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int cs32 = 0;
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/* TODO(sjg): Implement this for 64-bit mode */
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return cs32;
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}
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static int setup_info_table(struct efi_priv *priv, int size)
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{
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struct efi_info_hdr *info;
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efi_status_t ret;
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/* Get some memory for our info table */
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priv->info_size = size;
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info = efi_malloc(priv, priv->info_size, &ret);
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if (ret) {
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printhex2(ret);
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puts(" No memory for info table: ");
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return ret;
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}
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memset(info, '\0', sizeof(*info));
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info->version = EFI_TABLE_VERSION;
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info->hdr_size = sizeof(*info);
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priv->info = info;
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priv->next_hdr = (char *)info + info->hdr_size;
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return 0;
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}
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static void add_entry_addr(struct efi_priv *priv, enum efi_entry_t type,
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void *ptr1, int size1, void *ptr2, int size2)
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{
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struct efi_entry_hdr *hdr = priv->next_hdr;
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hdr->type = type;
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hdr->size = size1 + size2;
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hdr->addr = 0;
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hdr->link = ALIGN(sizeof(*hdr) + hdr->size, 16);
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priv->next_hdr += hdr->link;
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memcpy(hdr + 1, ptr1, size1);
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memcpy((void *)(hdr + 1) + size1, ptr2, size2);
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priv->info->total_size = (ulong)priv->next_hdr - (ulong)priv->info;
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}
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/**
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* efi_main() - Start an EFI image
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*
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* This function is called by our EFI start-up code. It handles running
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* U-Boot. If it returns, EFI will continue.
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*/
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efi_status_t efi_main(efi_handle_t image, struct efi_system_table *sys_table)
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{
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struct efi_priv local_priv, *priv = &local_priv;
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struct efi_boot_services *boot = sys_table->boottime;
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struct efi_mem_desc *desc;
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struct efi_entry_memmap map;
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ulong key, desc_size, size;
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efi_status_t ret;
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u32 version;
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int cs32;
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ret = efi_init(priv, "Payload", image, sys_table);
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if (ret) {
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printhex2(ret); puts(" efi_init() failed\n");
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return ret;
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}
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global_priv = priv;
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cs32 = get_codeseg32();
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if (cs32 < 0)
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return EFI_UNSUPPORTED;
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/* Get the memory map so we can switch off EFI */
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size = 0;
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ret = boot->get_memory_map(&size, NULL, &key, &desc_size, &version);
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if (ret != EFI_BUFFER_TOO_SMALL) {
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printhex2(BITS_PER_LONG);
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printhex2(ret);
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puts(" No memory map\n");
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return ret;
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}
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size += 1024; /* Since doing a malloc() may change the memory map! */
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desc = efi_malloc(priv, size, &ret);
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if (!desc) {
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printhex2(ret);
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puts(" No memory for memory descriptor: ");
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return ret;
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}
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ret = setup_info_table(priv, size + 128);
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if (ret)
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return ret;
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ret = boot->get_memory_map(&size, desc, &key, &desc_size, &version);
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if (ret) {
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printhex2(ret);
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puts(" Can't get memory map\n");
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return ret;
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}
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ret = boot->exit_boot_services(image, key);
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if (ret) {
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/*
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* Unfortunately it happens that we cannot exit boot services
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* the first time. But the second time it work. I don't know
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* why but this seems to be a repeatable problem. To get
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* around it, just try again.
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*/
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printhex2(ret);
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puts(" Can't exit boot services\n");
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size = sizeof(desc);
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ret = boot->get_memory_map(&size, desc, &key, &desc_size,
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&version);
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if (ret) {
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printhex2(ret);
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puts(" Can't get memory map\n");
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return ret;
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}
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ret = boot->exit_boot_services(image, key);
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if (ret) {
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printhex2(ret);
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puts(" Can't exit boot services 2\n");
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return ret;
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}
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}
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map.version = version;
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map.desc_size = desc_size;
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add_entry_addr(priv, EFIET_MEMORY_MAP, &map, sizeof(map), desc, size);
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add_entry_addr(priv, EFIET_END, NULL, 0, 0, 0);
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/* The EFI UART won't work now, switch to a debug one */
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use_uart = true;
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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;
|
||||
}
|
||||
Loading…
Reference in a new issue