stub: execute EFI image with an embedded kernel, initrd, cmdline sections

Locate the following embedded PE sections
  .linux - bzImage
  .inird - initrd cpio archive
  .cmdline - kernel command line
and hand over control to the bzImage.

10 files changed, 303 insertions, 41 deletions

diff --git a/.gitignore b/.gitignore
index 047bb03..d482a5d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,8 +9,11 @@
 .dirstamp
 /gummiboot
 /gummiboot.so
-/gummibootia32.efi
 /gummibootx64.efi
+/gummibootia32.efi
+/stub.so
+/stubx64.efi
+/stubia32.efi
 /test-disk
 
 Makefile
diff --git a/Makefile.am b/Makefile.am
index c4cda7f..528f83c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -74,20 +74,6 @@ CLEANFILES += man/gummiboot.8
 # EFI compilation -- this part of the build system uses custom make rules and
 # bypasses regular automake to provide absolute control on compiler and linker
 # flags.
-efi_loadername = gummiboot$(MACHINE_TYPE_NAME).efi
-efi_sources = \
-	src/efi/util.c \
-	src/efi/console.c \
-	src/efi/graphics.c \
-	src/efi/pefile.c \
-	src/efi/gummiboot.c
-
-efi_headers = \
-	src/efi/util.h \
-	src/efi/console.h \
-	src/efi/graphics.h \
-	src/efi/pefile.h
-
 efi_cppflags = \
 	$(EFI_CPPFLAGS) \
 	-I$(top_builddir) -include config.h \
@@ -128,25 +114,74 @@ efi_ldflags = \
 	-L $(EFI_LIB_DIR) \
 	$(EFI_LDS_DIR)/crt0-efi-$(ARCH).o
 
-efi_objects = $(addprefix $(top_builddir)/,$(efi_sources:.c=.o))
-efi_solib = $(top_builddir)/src/efi/gummiboot.so
+# ------------------------------------------------------------------------------
+gummiboot_headers = \
+	src/efi/util.h \
+	src/efi/console.h \
+	src/efi/graphics.h \
+	src/efi/pefile.h
+
+gummiboot_sources = \
+	src/efi/util.c \
+	src/efi/console.c \
+	src/efi/graphics.c \
+	src/efi/pefile.c \
+	src/efi/gummiboot.c
+
+gummiboot_objects = $(addprefix $(top_builddir)/,$(gummiboot_sources:.c=.o))
+gummiboot_solib = $(top_builddir)/src/efi/gummiboot.so
+gummiboot = gummiboot$(MACHINE_TYPE_NAME).efi
+
+gummibootlib_DATA = $(gummiboot)
+CLEANFILES += $(gummiboot_objects) $(gummiboot_solib) $(gummiboot)
+EXTRA_DIST += $(gimmiboot_sources) $(gummiboot_headers)
+
+$(top_builddir)/src/efi/%.o: $(top_srcdir)/src/efi/%.c $(addprefix $(top_srcdir)/,$(gummiboot_headers))
+	@$(MKDIR_P) $(top_builddir)/src/efi/
+	$(AM_V_CC)$(EFI_CC) $(efi_cppflags) $(efi_cflags) -c $< -o $@
+
+$(gummiboot_solib): $(gummiboot_objects)
+	$(AM_V_CCLD)$(LD) $(efi_ldflags) $(gummiboot_objects) \
+		-o $@ -lefi -lgnuefi $(shell $(CC) -print-libgcc-file-name); \
+	nm -D -u $@ | grep ' U ' && exit 1 || :
+.DELETE_ON_ERROR: $(gummboot_solib)
+
+$(gummiboot): $(gummiboot_solib)
+	$(AM_V_GEN) objcopy -j .text -j .sdata -j .data -j .dynamic \
+	  -j .dynsym -j .rel -j .rela -j .reloc \
+	  --target=efi-app-$(ARCH) $< $@
 
 # ------------------------------------------------------------------------------
-gummibootlib_DATA = $(efi_loadername)
-CLEANFILES += $(efi_objects) $(efi_solib) $(efi_loadername)
-EXTRA_DIST += $(efi_sources) $(efi_headers)
+stub_headers = \
+	src/efi/util.h \
+	src/efi/pefile.h \
+	src/efi/linux.h
+
+stub_sources = \
+	src/efi/util.c \
+	src/efi/pefile.c \
+	src/efi/linux.c \
+	src/efi/stub.c
+
+stub_objects = $(addprefix $(top_builddir)/,$(stub_sources:.c=.o))
+stub_solib = $(top_builddir)/src/efi/stub.so
+stub = stub$(MACHINE_TYPE_NAME).efi
+
+gummibootlib_DATA += $(stub)
+CLEANFILES += $(stub_objects) $(stub_solib) $(stub)
+EXTRA_DIST += $(stub_sources) $(stub_headers)
 
-$(top_builddir)/src/efi/%.o: $(top_srcdir)/src/efi/%.c $(addprefix $(top_srcdir)/,$(efi_headers))
+$(top_builddir)/src/efi/%.o: $(top_srcdir)/src/efi/%.c $(addprefix $(top_srcdir)/,$(stub_headers))
 	@$(MKDIR_P) $(top_builddir)/src/efi/
 	$(AM_V_CC)$(EFI_CC) $(efi_cppflags) $(efi_cflags) -c $< -o $@
 
-$(efi_solib): $(efi_objects)
-	$(AM_V_CCLD)$(LD) $(efi_ldflags) $(efi_objects) \
+$(stub_solib): $(stub_objects)
+	$(AM_V_CCLD)$(LD) $(efi_ldflags) $(stub_objects) \
 		-o $@ -lefi -lgnuefi $(shell $(CC) -print-libgcc-file-name); \
 	nm -D -u $@ | grep ' U ' && exit 1 || :
-.DELETE_ON_ERROR: $(efi_solib)
+.DELETE_ON_ERROR: $(gummboot_solib)
 
-$(efi_loadername): $(efi_solib)
+$(stub): $(stub_solib)
 	$(AM_V_GEN) objcopy -j .text -j .sdata -j .data -j .dynamic \
 	  -j .dynsym -j .rel -j .rela -j .reloc \
 	  --target=efi-app-$(ARCH) $< $@
diff --git a/src/efi/graphics.c b/src/efi/graphics.c
index 0810538..11305b8 100644
--- a/src/efi/graphics.c
+++ b/src/efi/graphics.c
@@ -208,7 +208,7 @@ EFI_STATUS bmp_parse_header(UINT8 *bmp, UINTN size, struct bmp_dib **ret_dib,
         return EFI_SUCCESS;
 }
 
-static void pixel_blend(UINT32 *dst, const UINT32 source) {
+static VOID pixel_blend(UINT32 *dst, const UINT32 source) {
         UINT32 alpha, src, src_rb, src_g, dst_rb, dst_g, rb, g;
 
         alpha = (source & 0xff);
diff --git a/src/efi/gummiboot.c b/src/efi/gummiboot.c
index f9da90d..ff1226d 100644
--- a/src/efi/gummiboot.c
+++ b/src/efi/gummiboot.c
@@ -32,6 +32,7 @@
 #include "console.h"
 #include "graphics.h"
 #include "pefile.h"
+#include "linux.h"
 
 #ifndef EFI_OS_INDICATIONS_BOOT_TO_FW_UI
 #define EFI_OS_INDICATIONS_BOOT_TO_FW_UI 0x0000000000000001ULL
@@ -64,7 +65,7 @@ typedef struct {
         CHAR16 *options;
         CHAR16 *splash;
         CHAR16 key;
-        EFI_STATUS (*call)(void);
+        EFI_STATUS (*call)(VOID);
         BOOLEAN no_autoselect;
         BOOLEAN non_unique;
 } ConfigEntry;
@@ -85,7 +86,7 @@ typedef struct {
         CHAR16 *entries_auto;
 } Config;
 
-static void cursor_left(UINTN *cursor, UINTN *first)
+static VOID cursor_left(UINTN *cursor, UINTN *first)
 {
         if ((*cursor) > 0)
                 (*cursor)--;
@@ -93,7 +94,7 @@ static void cursor_left(UINTN *cursor, UINTN *first)
                 (*first)--;
 }
 
-static void cursor_right(UINTN *cursor, UINTN *first, UINTN x_max, UINTN len)
+static VOID cursor_right(UINTN *cursor, UINTN *first, UINTN x_max, UINTN len)
 {
         if ((*cursor)+1 < x_max)
                 (*cursor)++;
@@ -1558,7 +1559,7 @@ static VOID config_title_generate(Config *config) {
         }
 }
 
-static BOOLEAN config_entry_add_call(Config *config, CHAR16 *title, EFI_STATUS (*call)(void)) {
+static BOOLEAN config_entry_add_call(Config *config, CHAR16 *title, EFI_STATUS (*call)(VOID)) {
         ConfigEntry *entry;
 
         entry = AllocateZeroPool(sizeof(ConfigEntry));
@@ -1766,7 +1767,7 @@ static EFI_STATUS image_start(EFI_HANDLE parent_image, const Config *config, con
         if (options) {
                 EFI_LOADED_IMAGE *loaded_image;
 
-                err = uefi_call_wrapper(BS->OpenProtocol, 6, image, &LoadedImageProtocol, (void **)&loaded_image,
+                err = uefi_call_wrapper(BS->OpenProtocol, 6, image, &LoadedImageProtocol, (VOID **)&loaded_image,
                                         parent_image, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL);
                 if (EFI_ERROR(err)) {
                         Print(L"Error getting LoadedImageProtocol handle: %r", err);
@@ -1847,7 +1848,7 @@ EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *sys_table) {
         efivar_set(L"LoaderFirmwareType", s, FALSE);
         FreePool(s);
 
-        err = uefi_call_wrapper(BS->OpenProtocol, 6, image, &LoadedImageProtocol, (void **)&loaded_image,
+        err = uefi_call_wrapper(BS->OpenProtocol, 6, image, &LoadedImageProtocol, (VOID **)&loaded_image,
                                 image, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL);
         if (EFI_ERROR(err)) {
                 Print(L"Error getting a LoadedImageProtocol handle: %r ", err);
diff --git a/src/efi/linux.c b/src/efi/linux.c
new file mode 100644
index 0000000..922a30f
--- /dev/null
+++ b/src/efi/linux.c
@@ -0,0 +1,128 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * Copyright (C) 2015 Kay Sievers <kay@vrfy.org>
+ */
+
+#include <efi.h>
+#include <efilib.h>
+
+#include "util.h"
+#include "linux.h"
+
+#define SETUP_MAGIC             0x53726448      /* "HdrS" */
+struct SetupHeader {
+        UINT8 boot_sector[0x01f1];
+        UINT8 setup_secs;
+        UINT16 root_flags;
+        UINT32 sys_size;
+        UINT16 ram_size;
+        UINT16 video_mode;
+        UINT16 root_dev;
+        UINT16 signature;
+        UINT16 jump;
+        UINT32 header;
+        UINT16 version;
+        UINT16 su_switch;
+        UINT16 setup_seg;
+        UINT16 start_sys;
+        UINT16 kernel_ver;
+        UINT8 loader_id;
+        UINT8 load_flags;
+        UINT16 movesize;
+        UINT32 code32_start;
+        UINT32 ramdisk_start;
+        UINT32 ramdisk_len;
+        UINT32 bootsect_kludge;
+        UINT16 heap_end;
+        UINT8 ext_loader_ver;
+        UINT8 ext_loader_type;
+        UINT32 cmd_line_ptr;
+        UINT32 ramdisk_max;
+        UINT32 kernel_alignment;
+        UINT8 relocatable_kernel;
+        UINT8 min_alignment;
+        UINT16 xloadflags;
+        UINT32 cmdline_size;
+        UINT32 hardware_subarch;
+        UINT64 hardware_subarch_data;
+        UINT32 payload_offset;
+        UINT32 payload_length;
+        UINT64 setup_data;
+        UINT64 pref_address;
+        UINT32 init_size;
+        UINT32 handover_offset;
+} __attribute__((packed));
+
+#ifdef __x86_64__
+typedef VOID(*handover_f)(VOID *image, EFI_SYSTEM_TABLE *table, struct SetupHeader *setup);
+static inline VOID linux_efi_handover(EFI_HANDLE image, struct SetupHeader *setup) {
+        handover_f handover;
+
+        asm volatile ("cli");
+        handover = (handover_f)((UINTN)setup->code32_start + 512 + setup->handover_offset);
+        handover(image, ST, setup);
+}
+#else
+typedef VOID(*handover_f)(VOID *image, EFI_SYSTEM_TABLE *table, struct SetupHeader *setup) __attribute__((regparm(0)));
+static inline VOID linux_efi_handover(EFI_HANDLE image, struct SetupHeader *setup) {
+        handover_f handover;
+
+        handover = (handover_f)((UINTN)boot_setup->code32_start + setup->handover_offset);
+        handover(image, ST, setup);
+}
+#endif
+
+EFI_STATUS linux_exec(EFI_HANDLE *image,
+                      CHAR8 *cmdline, UINTN linux_addr,
+                      UINTN initrd_addr, UINTN initrd_size) {
+        struct SetupHeader *image_setup;
+        struct SetupHeader *boot_setup;
+        EFI_PHYSICAL_ADDRESS addr;
+        EFI_STATUS err;
+
+        image_setup = (struct SetupHeader *)(linux_addr);
+        if (image_setup->signature != 0xAA55 || image_setup->header != SETUP_MAGIC)
+                return EFI_LOAD_ERROR;
+
+        if (image_setup->version < 0x20b || !image_setup->relocatable_kernel)
+                return EFI_LOAD_ERROR;
+
+        addr = 0x3fffffff;
+        err = uefi_call_wrapper(BS->AllocatePages, 4, AllocateMaxAddress, EfiLoaderData,
+                                EFI_SIZE_TO_PAGES(0x4000), &addr);
+        if (EFI_ERROR(err))
+                return err;
+        boot_setup = (struct SetupHeader *)addr;
+        ZeroMem(boot_setup, 0x4000);
+        CopyMem(boot_setup, image_setup, sizeof(struct SetupHeader));
+        boot_setup->loader_id = 0xff;
+
+        boot_setup->code32_start = (UINT32)linux_addr + (image_setup->setup_secs+1) * 512;
+
+        if (cmdline) {
+                addr = 0xA0000;
+                err = uefi_call_wrapper(BS->AllocatePages, 4, AllocateMaxAddress, EfiLoaderData,
+                                        EFI_SIZE_TO_PAGES(strlena(cmdline) + 1), &addr);
+                if (EFI_ERROR(err))
+                        return err;
+                CopyMem((VOID *)addr, cmdline, strlena(cmdline) + 1);
+                boot_setup->cmd_line_ptr = (UINT32)addr;
+        }
+
+        boot_setup->ramdisk_start = (UINT32)initrd_addr;
+        boot_setup->ramdisk_len = (UINT32)initrd_size;
+
+        linux_efi_handover(image, boot_setup);
+        return EFI_LOAD_ERROR;
+}
diff --git a/src/efi/linux.h b/src/efi/linux.h
new file mode 100644
index 0000000..020c728
--- /dev/null
+++ b/src/efi/linux.h
@@ -0,0 +1,23 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * Copyright (C) 2015 Kay Sievers <kay@vrfy.org>
+ */
+
+#ifndef __GUMMIBOOT_kernel_H
+#define __GUMMIBOOT_kernel_H
+
+EFI_STATUS linux_exec(EFI_HANDLE *image,
+                      CHAR8 *cmdline, UINTN linux_addr,
+                      UINTN initrd_addr, UINTN initrd_size);
+#endif
diff --git a/src/efi/pefile.c b/src/efi/pefile.c
index 6ac28da..5d750e0 100644
--- a/src/efi/pefile.c
+++ b/src/efi/pefile.c
@@ -11,8 +11,7 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * Lesser General Public License for more details.
  *
- * Copyright (C) 2012-2013 Kay Sievers <kay@vrfy.org>
- * Copyright (C) 2012 Harald Hoyer <harald@redhat.com>
+ * Copyright (C) 2015 Kay Sievers <kay@vrfy.org>
  */
 
 #include <efi.h>
@@ -154,7 +153,6 @@ EFI_STATUS pefile_locate_sections(EFI_FILE *dir, CHAR16 *path, CHAR8 **sections,
                         err = EFI_LOAD_ERROR;
                         goto out;
                 }
-
                 for (j = 0; sections[j]; j++) {
                         if (strcmpa(sections[j], sect.Name) != 0)
                                 continue;
diff --git a/src/efi/stub.c b/src/efi/stub.c
new file mode 100644
index 0000000..c1be3d6
--- /dev/null
+++ b/src/efi/stub.c
@@ -0,0 +1,71 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/* This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * Copyright (C) 2015 Kay Sievers <kay@vrfy.org>
+ */
+
+#include <efi.h>
+#include <efilib.h>
+
+#include "util.h"
+#include "pefile.h"
+#include "linux.h"
+
+EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *sys_table) {
+        EFI_LOADED_IMAGE *loaded_image;
+        EFI_FILE *root_dir;
+        CHAR16 *loaded_image_path;
+        CHAR8 *sections[] = {
+                (UINT8 *)".cmdline",
+                (UINT8 *)".linux",
+                (UINT8 *)".initrd",
+                NULL
+        };
+        UINTN addrs[3] = {};
+        UINTN offs[3] = {};
+        UINTN szs[3] = {};
+        EFI_STATUS err;
+
+        InitializeLib(image, sys_table);
+
+        err = uefi_call_wrapper(BS->OpenProtocol, 6, image, &LoadedImageProtocol, (VOID **)&loaded_image,
+                                image, NULL, EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+        if (EFI_ERROR(err)) {
+                Print(L"Error getting a LoadedImageProtocol handle: %r ", err);
+                uefi_call_wrapper(BS->Stall, 1, 3 * 1000 * 1000);
+                return err;
+        }
+
+        root_dir = LibOpenRoot(loaded_image->DeviceHandle);
+        if (!root_dir) {
+                Print(L"Unable to open root directory: %r ", err);
+                uefi_call_wrapper(BS->Stall, 1, 3 * 1000 * 1000);
+                return EFI_LOAD_ERROR;
+        }
+
+        loaded_image_path = DevicePathToStr(loaded_image->FilePath);
+
+        err = pefile_locate_sections(root_dir, loaded_image_path, sections, addrs, offs, szs);
+        if (EFI_ERROR(err)) {
+                Print(L"Unable to locate embedded .linux section: %r ", err);
+                uefi_call_wrapper(BS->Stall, 1, 3 * 1000 * 1000);
+                return err;
+        }
+
+        err = linux_exec(image, (CHAR8 *)"",
+                         (UINTN)loaded_image->ImageBase + addrs[1],
+                         (UINTN)loaded_image->ImageBase + addrs[2], szs[2]);
+
+        Print(L"Execution of embedded linux image failed: %r\n", err);
+        uefi_call_wrapper(BS->Stall, 1, 3 * 1000 * 1000);
+        return err;
+}
diff --git a/src/efi/util.c b/src/efi/util.c
index 191c071..5678b50 100644
--- a/src/efi/util.c
+++ b/src/efi/util.c
@@ -28,13 +28,13 @@
 static const EFI_GUID loader_guid = { 0x4a67b082, 0x0a4c, 0x41cf, {0xb6, 0xc7, 0x44, 0x0b, 0x29, 0xbb, 0x8c, 0x4f} };
 
 #ifdef __x86_64__
-UINT64 ticks_read(void) {
+UINT64 ticks_read(VOID) {
         UINT64 a, d;
         __asm__ volatile ("rdtsc" : "=a" (a), "=d" (d));
         return (d << 32) | a;
 }
 #else
-UINT64 ticks_read(void) {
+UINT64 ticks_read(VOID) {
         UINT64 val;
         __asm__ volatile ("rdtsc" : "=A" (val));
         return val;
@@ -42,7 +42,7 @@ UINT64 ticks_read(void) {
 #endif
 
 /* count TSC ticks during a millisecond delay */
-UINT64 ticks_freq(void) {
+UINT64 ticks_freq(VOID) {
         UINT64 ticks_start, ticks_end;
 
         ticks_start = ticks_read();
@@ -52,7 +52,7 @@ UINT64 ticks_freq(void) {
         return (ticks_end - ticks_start) * 1000;
 }
 
-UINT64 time_usec(void) {
+UINT64 time_usec(VOID) {
         UINT64 ticks;
         static UINT64 freq;
 
diff --git a/test/test-create-disk.sh b/test/test-create-disk.sh
index 3982223..9fdb3c3 100755
--- a/test/test-create-disk.sh
+++ b/test/test-create-disk.sh
@@ -19,8 +19,11 @@ cp test/splash.bmp mnt/EFI/gummiboot/
 [ -e /boot/shellx64.efi ] && cp /boot/shellx64.efi mnt/
 
 mkdir mnt/EFI/Linux
-objcopy --add-section .osrel=/etc/os-release --change-section-vma .osrel=0x20000 \
-  gummibootx64.efi mnt/EFI/Linux/Test-Linux.efi
+objcopy \
+  --add-section .osrel=/etc/os-release --change-section-vma .osrel=0x20000 \
+  --add-section .linux=/boot/$(cat /etc/machine-id)/$(uname -r)/linux --change-section-vma .linux=0x30000 \
+  --add-section .initrd=/boot/$(cat /etc/machine-id)/$(uname -r)/initrd --change-section-vma .initrd=0x3000000 \
+  stubx64.efi mnt/EFI/Linux/linux-test.efi
 
 # install entries
 mkdir -p mnt/loader/entries