* [PATCH v2 2/3] add CONFIG_PBL_BREAK option
2019-06-07 6:36 [PATCH v2 1/3] remove CONFIG_DEBUG_INFO Rouven Czerwinski
@ 2019-06-07 6:36 ` Rouven Czerwinski
2019-06-07 6:36 ` [PATCH v2 3/3] add gdb helper scripts to load barebox symbols Rouven Czerwinski
1 sibling, 0 replies; 3+ messages in thread
From: Rouven Czerwinski @ 2019-06-07 6:36 UTC (permalink / raw)
To: barebox; +Cc: Rouven Czerwinski, Oleksij Rempel
From: Oleksij Rempel <linux@rempel-privat.de>
With this option barebox will be build with breakpoint instruction
in early pbl stage.
Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
Signed-off-by: Rouven Czerwinski <r.czerwinski@pengutronix.de>
---
arch/arm/cpu/common.c | 13 +++++++++++++
arch/arm/cpu/start.c | 2 ++
arch/arm/include/asm/barebox-arm.h | 2 ++
common/Kconfig | 7 +++++++
4 files changed, 24 insertions(+)
diff --git a/arch/arm/cpu/common.c b/arch/arm/cpu/common.c
index 51fe7ed988..6fe3476aa2 100644
--- a/arch/arm/cpu/common.c
+++ b/arch/arm/cpu/common.c
@@ -30,6 +30,19 @@
#define R_ARM_RELATIVE 23
#define R_AARCH64_RELATIVE 1027
+void pbl_barebox_break(void)
+{
+ __asm__ __volatile__ (
+#ifdef CONFIG_PBL_BREAK
+ "bkpt #17\n"
+ "nop\n"
+#else
+ "nop\n"
+ "nop\n"
+#endif
+ );
+}
+
/*
* relocate binary to the currently running address
*/
diff --git a/arch/arm/cpu/start.c b/arch/arm/cpu/start.c
index 6573c2ef74..6bfc4da34c 100644
--- a/arch/arm/cpu/start.c
+++ b/arch/arm/cpu/start.c
@@ -168,6 +168,8 @@ __noreturn void barebox_non_pbl_start(unsigned long membase,
barrier();
+ pbl_barebox_break();
+
pr_debug("memory at 0x%08lx, size 0x%08lx\n", membase, memsize);
arm_endmem = endmem;
diff --git a/arch/arm/include/asm/barebox-arm.h b/arch/arm/include/asm/barebox-arm.h
index a11d34923d..12765b7277 100644
--- a/arch/arm/include/asm/barebox-arm.h
+++ b/arch/arm/include/asm/barebox-arm.h
@@ -55,6 +55,7 @@ static inline unsigned long global_variable_offset(void)
}
void setup_c(void);
+void pbl_barebox_break(void);
void relocate_to_current_adr(void);
void relocate_to_adr(unsigned long target);
void __noreturn barebox_arm_entry(unsigned long membase, unsigned long memsize, void *boarddata);
@@ -177,6 +178,7 @@ static inline unsigned long arm_mem_barebox_image(unsigned long membase,
(uint32_t r0, uint32_t r1, uint32_t r2) \
{ \
__barebox_arm_head(); \
+ pbl_barebox_break(); \
__##name(r0, r1, r2); \
} \
static void NAKED noinline __##name \
diff --git a/common/Kconfig b/common/Kconfig
index ffb7537592..4124857a0a 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -1245,6 +1245,13 @@ config DEBUG_INITCALLS
help
If enabled this will print initcall traces.
+
+config PBL_BREAK
+ bool "Execute software break on pbl start"
+ help
+ If this enabled, barebox will be compiled with BKPT instruction
+ on early pbl init. This option be used only with JTAG debugger!
+
endmenu
config HAS_DEBUG_LL
--
2.21.0
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^ permalink raw reply [flat|nested] 3+ messages in thread* [PATCH v2 3/3] add gdb helper scripts to load barebox symbols
2019-06-07 6:36 [PATCH v2 1/3] remove CONFIG_DEBUG_INFO Rouven Czerwinski
2019-06-07 6:36 ` [PATCH v2 2/3] add CONFIG_PBL_BREAK option Rouven Czerwinski
@ 2019-06-07 6:36 ` Rouven Czerwinski
1 sibling, 0 replies; 3+ messages in thread
From: Rouven Czerwinski @ 2019-06-07 6:36 UTC (permalink / raw)
To: barebox; +Cc: Rouven Czerwinski
Add a gdb script with two helper functions which use the new
pbl_barebox_break symbol to calculate the current barebox load address
on the device and loads a barebox ELF file to this address.
Signed-off-by: Rouven Czerwinski <r.czerwinski@pengutronix.de>
---
Documentation/user/debugging.rst | 21 +++++++++++
Documentation/user/user-manual.rst | 1 +
scripts/gdb/helper.py | 60 ++++++++++++++++++++++++++++++
3 files changed, 82 insertions(+)
create mode 100644 Documentation/user/debugging.rst
create mode 100644 scripts/gdb/helper.py
diff --git a/Documentation/user/debugging.rst b/Documentation/user/debugging.rst
new file mode 100644
index 0000000000..15cb439043
--- /dev/null
+++ b/Documentation/user/debugging.rst
@@ -0,0 +1,21 @@
+Debugging with OpenOCD
+======================
+
+Barebox can be configured to break on prebootloader and main barebox entry. This
+breakpoint can not be resumed and will stop the board to allow the user to
+attach a JTAG debugger with OpenOCD. Additionally, barebox provides helper
+scripts to load the symbols from the ELF binaries.
+The python scripts require `pyelftools`.
+To load the scripts into your gdb session, run the following command in the
+barebox directory:
+
+.. code-block:: none
+
+ (gdb) source scripts/gdb/helper.py
+
+This makes two new commands available in gdb, `bb-load-symbols` and
+`bb-skip-break`. `bb-load-symbols` can load either the main `barebox` file or
+one of the .pbl files in the image directories. The board needs to be stopped in
+either the prebootloader or main barebox breakpoint, and gdb needs to be
+connected to OpenOCD. To continue booting the board, `bb-skip-break` jumps over
+the breakpoint and continues the barebox execution.
diff --git a/Documentation/user/user-manual.rst b/Documentation/user/user-manual.rst
index 516b760b1b..f04981c3f0 100644
--- a/Documentation/user/user-manual.rst
+++ b/Documentation/user/user-manual.rst
@@ -33,6 +33,7 @@ Contents:
system-reset
state
random
+ debugging
* :ref:`search`
* :ref:`genindex`
diff --git a/scripts/gdb/helper.py b/scripts/gdb/helper.py
new file mode 100644
index 0000000000..4041789890
--- /dev/null
+++ b/scripts/gdb/helper.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python
+
+import gdb
+
+try:
+ from elftools.elf.elffile import ELFFile
+ from elftools.common.exceptions import ELFError
+except ImportError:
+ gdb.write("The barebox helper requires pyelftools\n", gdb.STDERR)
+ exit(1)
+
+
+class BBSymbols(gdb.Command):
+
+ def __init__(self):
+ super(BBSymbols, self).__init__("bb-load-symbols", gdb.COMMAND_FILES,
+ gdb.COMPLETE_FILENAME)
+
+ def invoke(self, argument, from_tty):
+ path = argument
+ f = open(path, 'rb')
+
+ try:
+ elf = ELFFile(f)
+ except ELFError:
+ gdb.write("Selected file is not an ELF file\n", gdb.STDERR)
+ return
+
+ section = elf.get_section_by_name(".symtab")
+ if section is None:
+ gdb.write("Section .symtab not found\n", gdb.STDERR)
+ return
+ symbol = section.get_symbol_by_name("pbl_barebox_break")
+ if not symbol:
+ gdb.write("Symbol pbl_barebox_break in section {} in file {} not found\n"
+ .format(section.name, self.path), gdb.STDERR)
+ return
+ symbol = symbol[0]
+ pc = gdb.parse_and_eval("$pc")
+ symbol_address = int(symbol.entry.st_value)
+ address = int(pc) - symbol_address + 1
+ gdb.execute("symbol-file")
+ gdb.execute("add-symbol-file {} {}".format(path, address))
+
+
+BBSymbols()
+
+
+class BBSkip(gdb.Command):
+
+ def __init__(self):
+ super(BBSkip, self).__init__("bb-skip-break", gdb.COMMAND_BREAKPOINTS)
+
+ def invoke(self, arg, from_tty):
+ pc = gdb.parse_and_eval("$pc")
+ nop_address = int(pc) + 2
+ gdb.execute("jump *{}".format(nop_address))
+
+
+BBSkip()
--
2.21.0
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^ permalink raw reply [flat|nested] 3+ messages in thread