50a81748fd
This patch adds the ability to attach a GDB host through the UART to a running payload. Libpayload implements a small stub that can parse and respond to the GDB remote protocol and provide the required primitives (reading/writing registers/memory, etc.) to allow GDB to control execution. The goal of this implementation is to be as small and uninvasive as possible. It implements only the minimum amount of primitives required, and relies on GDB's impressive workaround capabilities (such as emulating breakpoints by temporarily replacing instructions) for the more complicated features. This way, a relatively tiny amount of code on the firmware side opens a vast range of capabilities to the user, not just in debugging but also in remote-controlling the firmware to change its behavior (e.g. through GDBs ability to modify variables and call functions). By default, a system with the REMOTEGDB Kconfig will only trap into GDB when executing halt() (including the calls from die_if(), assert(), and exception handlers). In addition, payloads can manually call gdb_enter() if desired. It will print a final "Ready for GDB connection." on the serial, detach the normal serial output driver and wait for the commands that GDB starts sending on attach. Based on original implementation by Gabe Black <gabeblack@chromium.org>. BUG=chrome-os-partner:18390 TEST=Boot a GDB enabled image in recovery mode (or get it to hit a halt()), close your terminal, execute '<toolchain>-gdb --symbols /build/<board>/firmware/depthcharge_gdb/depthcharge.elf --directory ~/trunk/src/third_party/coreboot/payloads/libpayload --directory ~/trunk/src/platform/depthcharge --directory ~/trunk/src/platform/vboot_reference --ex "target remote <cpu_uart_pty>"' and behold the magic. (You can also SIGSTOP your terminal's parent shell and the terminal itself, and SIGCONT them in reverse order after GDB exits. More convenient wrapper tools to do all this automatically coming soon.) Original-Change-Id: Ib440d1804126cdfdac4a8801f5015b4487e25269 Original-Signed-off-by: Julius Werner <jwerner@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/202563 Original-Reviewed-by: Stefan Reinauer <reinauer@chromium.org> (cherry picked from commit 9c4a642c7be2faf122fef39bdfaddd64aec68b77) Signed-off-by: Marc Jones <marc.jones@se-eng.com> Change-Id: I9238b4eb19d3ab2c98e4e1c5946cd7d252ca3c3b Reviewed-on: http://review.coreboot.org/8119 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
51 lines
2.1 KiB
Makefile
51 lines
2.1 KiB
Makefile
##
|
|
## This file is part of the libpayload project.
|
|
##
|
|
## Copyright (C) 2008 Advanced Micro Devices, Inc.
|
|
##
|
|
## Redistribution and use in source and binary forms, with or without
|
|
## modification, are permitted provided that the following conditions
|
|
## are met:
|
|
## 1. Redistributions of source code must retain the above copyright
|
|
## notice, this list of conditions and the following disclaimer.
|
|
## 2. Redistributions in binary form must reproduce the above copyright
|
|
## notice, this list of conditions and the following disclaimer in the
|
|
## documentation and/or other materials provided with the distribution.
|
|
## 3. The name of the author may not be used to endorse or promote products
|
|
## derived from this software without specific prior written permission.
|
|
##
|
|
## THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
## ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
## IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
## ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
## FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
## DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
## OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
## HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
## LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
## OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
## SUCH DAMAGE.
|
|
##
|
|
|
|
CFLAGS += -mthumb -march=armv7-a
|
|
arm_asm_flags = -Wa,-mthumb -Wa,-mimplicit-it=always -Wa,-mno-warn-deprecated
|
|
|
|
head.o-y += head.S
|
|
libc-y += eabi_compat.c
|
|
libc-y += main.c sysinfo.c
|
|
libc-y += timer.c coreboot.c util.S
|
|
libc-y += virtual.c
|
|
libc-y += exception_asm.S exception.c
|
|
libc-y += cache.c cpu.S
|
|
libc-y += selfboot.c
|
|
|
|
# Will fall back to default_memXXX() in libc/memory.c if GPL not allowed.
|
|
libc-$(CONFIG_LP_GPL) += memcpy.S memset.S memmove.S
|
|
|
|
libgdb-y += gdb.c
|
|
|
|
libcbfs-$(CONFIG_LP_CBFS) += dummy_media.c
|
|
|
|
# Add other classes here when you put assembly files into them!
|
|
head.o-S-ccopts += $(arm_asm_flags)
|
|
libc-S-ccopts += $(arm_asm_flags)
|