add gdb helper scripts to load barebox symbols

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>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 60 insertions, 0 deletions

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()