Hi Simon,
On Fri, Jul 31, 2015 at 11:31 PM, Simon Glass sjg@chromium.org wrote:
It is useful to be able to load U-Boot onto a board even it is it already
Nits: even it is
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 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 | 21 ++++ arch/x86/config.mk | 3 + include/common.h | 7 ++ include/efi.h | 4 + lib/efi/Kconfig | 21 ++++ lib/efi/Makefile | 9 ++ lib/efi/efi_stub.c | 299 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 7 files changed, 364 insertions(+) create mode 100644 lib/efi/efi_stub.c
diff --git a/Makefile b/Makefile index 6da9224..755eec8 100644 --- a/Makefile +++ b/Makefile @@ -751,6 +751,7 @@ 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 @@ -786,6 +787,9 @@ 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) @@ -1083,6 +1087,23 @@ 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
$(call if_changed_dep,cpp_lds)+u-boot-payload: u-boot-dtb.bin.o u-boot-payload.lds \
FORCE$(LD) $(LDFLAGS_EFI) -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))
Can we convert this to use quiet_cmd_xxx format so that it won't print anything by default?
+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 a1c0eb2..48eb5f5 100644 --- a/arch/x86/config.mk +++ b/arch/x86/config.mk @@ -35,6 +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 5d80373..34844e4 100644 --- a/include/efi.h +++ b/include/efi.h @@ -269,11 +269,15 @@ 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_STUBhelpEFI does not support mixing 32-bit and 64-bit modes. This is asignificant problem because it means that you must build a stub withthe correct type for EFI to load it correctly. If you are using32-bit EFI, select 32-bit here, else select 64-bit. Failure to dothis 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..7259720 --- /dev/null +++ b/lib/efi/efi_stub.c @@ -0,0 +1,299 @@ +/*
- Copyright (c) 2015 Google, Inc
- SPDX-License-Identifier: GPL-2.0+
- EFI information obtained here:
- 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) +{
typedef void (*func_t)(int bist, int unused, ulong info);+#ifdef CONFIG_EFI_STUB_32BIT
((func_t)addr)(bist, 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;+}
Regards, Bin