EFI firmware determines where to load the GRUB EFI at runtime, and so the
addresses of debug symbols are not known ahead of time. There is a command
defined in the gdb_grub script which will load the debug symbols at the
appropriate addresses, if given given the application load address for GRUB.
So add a command named "gdbinfo" to allow the user to print this GDB command
string with the application load address on-demand. For the outputted GDB
command to have any effect when entered into a GDB session, GDB should have
been started with the script as an argument to the -x option or sourced into
an active GDB session before running the outputted command.
Documentation for the gdbinfo command is also added.
Co-developed-by: Peter Jones <pjo...@redhat.com>
Signed-off-by: Peter Jones <pjo...@redhat.com>
Signed-off-by: Glenn Washburn <developm...@efficientek.com>
---
Range-diff against v1:
1: 1d438175061f ! 1: 24106a4ff806 gdb: Add gdbinfo command for printing the
load address of the EFI application
@@ grub-core/kern/efi/init.c: grub_addr_t grub_modbase;
messages. */
grub_console_init ();
@@ grub-core/kern/efi/init.c: grub_efi_init (void)
- 0, 0, 0, NULL);
+ grub_efi_system_table->boot_services->set_watchdog_timer (0, 0, 0,
NULL);
grub_efidisk_init ();
+
@@ include/grub/efi/debug.h (new)
+#endif /* ! GRUB_EFI_DEBUG_HEADER */
## include/grub/efi/efi.h ##
-@@ include/grub/efi/efi.h: grub_err_t
grub_arch_efi_linux_boot_image(grub_addr_t addr, grub_size_t size,
+@@ include/grub/efi/efi.h: grub_err_t
grub_arch_efi_linux_load_image_header(grub_file_t file,
+ grub_err_t grub_arch_efi_linux_boot_image(grub_addr_t addr, grub_size_t
size,
char *args);
- #endif
-grub_addr_t grub_efi_modules_addr (void);
+grub_addr_t grub_efi_section_addr (const char *section);
docs/grub.texi | 13 ++++++++++++
grub-core/Makefile.core.def | 1 +
grub-core/kern/efi/debug.c | 38 ++++++++++++++++++++++++++++++++++
grub-core/kern/efi/efi.c | 4 ++--
grub-core/kern/efi/init.c | 5 ++++-
include/grub/efi/debug.h | 41 +++++++++++++++++++++++++++++++++++++
include/grub/efi/efi.h | 2 +-
7 files changed, 100 insertions(+), 4 deletions(-)
create mode 100644 grub-core/kern/efi/debug.c
create mode 100644 include/grub/efi/debug.h
diff --git a/docs/grub.texi b/docs/grub.texi
index 7ab1e0ab40ef..5fb074f66869 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -4301,6 +4301,7 @@ you forget a command, you can run the command
@command{help}
* export:: Export an environment variable
* false:: Do nothing, unsuccessfully
* fwsetup:: Reboot into the firmware setup menu
+* gdbinfo:: Provide info for debugging with GDB
* gettext:: Translate a string
* gptsync:: Fill an MBR based on GPT entries
* halt:: Shut down your computer
@@ -4833,6 +4834,18 @@ exit successfully if so.
@end deffn
+@node gdbinfo
+@subsection gdbinfo
+
+@deffn Command gdbinfo
+Output text to be used as a GDB command for a GDB session using the gdb_grub
+script and attached to a running GRUB instance. The GDB command that is
+output will tell GDB how to load debugging symbols to their proper runtime
+address. Currently this is only available for EFI platforms. See the Debugging
+in the developer documentation for more information.
+@end deffn
+
+
@node gettext
@subsection gettext
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 04549e868591..784f0a2136c2 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -211,6 +211,7 @@ kernel = {
efi = disk/efi/efidisk.c;
efi = kern/efi/efi.c;
+ efi = kern/efi/debug.c;
efi = kern/efi/init.c;
efi = kern/efi/mm.c;
efi = term/efi/console.c;
diff --git a/grub-core/kern/efi/debug.c b/grub-core/kern/efi/debug.c
new file mode 100644
index 000000000000..506ad90dca06
--- /dev/null
+++ b/grub-core/kern/efi/debug.c
@@ -0,0 +1,38 @@
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2022 Free Software Foundation, Inc.
+ *
+ * GRUB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
+ */
+/* debug.c - aides for debugging the EFI application */
+
+#include <grub/efi/debug.h>
+#include <grub/command.h>
+#include <grub/i18n.h>
+
+static grub_err_t
+grub_cmd_gdbinfo (struct grub_command *cmd __attribute__ ((unused)),
+ int argc __attribute__ ((unused)),
+ char **args __attribute__ ((unused)))
+{
+ grub_efi_print_gdb_info ();
+ return 0;
+}
+
+void
+grub_efi_register_debug_commands (void)
+{
+ grub_register_command_lockdown ("gdbinfo", grub_cmd_gdbinfo, 0,
+ N_("Print infomation useful for GDB
debugging"));
+}
diff --git a/grub-core/kern/efi/efi.c b/grub-core/kern/efi/efi.c
index 0e1ccf65ad2e..974fed8cb55c 100644
--- a/grub-core/kern/efi/efi.c
+++ b/grub-core/kern/efi/efi.c
@@ -303,7 +303,7 @@ grub_efi_get_variable (const char *var, const
grub_efi_guid_t *guid,
/* Search the mods section from the PE32/PE32+ image. This code uses
a PE32 header, but should work with PE32+ as well. */
grub_addr_t
-grub_efi_modules_addr (void)
+grub_efi_section_addr (const char *section_name)
{
grub_efi_loaded_image_t *image;
struct grub_msdos_image_header *header;
@@ -332,7 +332,7 @@ grub_efi_modules_addr (void)
i < coff_header->num_sections;
i++, section++)
{
- if (grub_strcmp (section->name, "mods") == 0)
+ if (grub_strcmp (section->name, section_name) == 0)
break;
}
diff --git a/grub-core/kern/efi/init.c b/grub-core/kern/efi/init.c
index e873ef5298ff..ae8c2e1e499b 100644
--- a/grub-core/kern/efi/init.c
+++ b/grub-core/kern/efi/init.c
@@ -19,6 +19,7 @@
#include <grub/efi/efi.h>
#include <grub/efi/console.h>
+#include <grub/efi/debug.h>
#include <grub/efi/disk.h>
#include <grub/efi/sb.h>
#include <grub/lockdown.h>
@@ -104,7 +105,7 @@ grub_addr_t grub_modbase;
void
grub_efi_init (void)
{
- grub_modbase = grub_efi_modules_addr ();
+ grub_modbase = grub_efi_section_addr ("mods");
/* First of all, initialize the console so that GRUB can display
messages. */
grub_console_init ();
@@ -127,6 +128,8 @@ grub_efi_init (void)
grub_efi_system_table->boot_services->set_watchdog_timer (0, 0, 0, NULL);
grub_efidisk_init ();
+
+ grub_efi_register_debug_commands ();
}
void (*grub_efi_net_config) (grub_efi_handle_t hnd,
diff --git a/include/grub/efi/debug.h b/include/grub/efi/debug.h
new file mode 100644
index 000000000000..c2d2a03b06f1
--- /dev/null
+++ b/include/grub/efi/debug.h
@@ -0,0 +1,41 @@
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2022 Free Software Foundation, Inc.
+ *
+ * GRUB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
+ */
+/* debug.h - declare variables and functions for EFI debugging support */
+
+#ifndef GRUB_EFI_DEBUG_HEADER
+#define GRUB_EFI_DEBUG_HEADER 1
+
+#include <grub/efi/efi.h>
+#include <grub/misc.h>
+
+
+void grub_efi_register_debug_commands (void);
+
+static inline void
+grub_efi_print_gdb_info (void)
+{
+ grub_addr_t text;
+
+ text = grub_efi_section_addr (".text");
+ if (!text)
+ return;
+
+ grub_printf ("dynamic_load_symbols %p\n", (void *)text);
+}
+
+#endif /* ! GRUB_EFI_DEBUG_HEADER */
diff --git a/include/grub/efi/efi.h b/include/grub/efi/efi.h
index 7071b8dc9783..5ec5af71eeb6 100644
--- a/include/grub/efi/efi.h
+++ b/include/grub/efi/efi.h
@@ -127,7 +127,7 @@ grub_err_t
grub_arch_efi_linux_load_image_header(grub_file_t file,
grub_err_t grub_arch_efi_linux_boot_image(grub_addr_t addr, grub_size_t size,
char *args);
-grub_addr_t grub_efi_modules_addr (void);
+grub_addr_t grub_efi_section_addr (const char *section);
void grub_efi_mm_init (void);
void grub_efi_mm_fini (void);
--
2.34.1
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