[U-Boot] [PATCH 15/37] binman: Add a function to create a sample ELF file
Simon Glass
sjg at chromium.org
Fri Jun 28 14:08:57 UTC 2019
It is useful to create an ELF file for testing purposes, with just the
right attributes used by the test. Add a function to handle this, along
with a test that it works correctly.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
tools/binman/elf.py | 98 ++++++++++++++++++++++++++++++++++++++++
tools/binman/elf_test.py | 20 ++++++++
2 files changed, 118 insertions(+)
diff --git a/tools/binman/elf.py b/tools/binman/elf.py
index 828681d76d0..e6dc6ec1a9b 100644
--- a/tools/binman/elf.py
+++ b/tools/binman/elf.py
@@ -5,11 +5,15 @@
# Handle various things related to ELF images
#
+from __future__ import print_function
+
from collections import namedtuple, OrderedDict
import command
import os
import re
+import shutil
import struct
+import tempfile
import tools
@@ -128,3 +132,97 @@ def LookupAndWriteSymbols(elf_fname, entry, section):
(msg, name, offset, value, len(value_bytes)))
entry.data = (entry.data[:offset] + value_bytes +
entry.data[offset + sym.size:])
+
+def MakeElf(elf_fname, text, data):
+ """Make an elf file with the given data in a single section
+
+ The output file has a several section including '.text' and '.data',
+ containing the info provided in arguments.
+
+ Args:
+ elf_fname: Output filename
+ text: Text (code) to put in the file's .text section
+ data: Data to put in the file's .data section
+ """
+ outdir = tempfile.mkdtemp(prefix='binman.elf.')
+ s_file = os.path.join(outdir, 'elf.S')
+
+ # Spilt the text into two parts so that we can make the entry point two
+ # bytes after the start of the text section
+ text_bytes1 = ['\t.byte\t%#x' % tools.ToByte(byte) for byte in text[:2]]
+ text_bytes2 = ['\t.byte\t%#x' % tools.ToByte(byte) for byte in text[2:]]
+ data_bytes = ['\t.byte\t%#x' % tools.ToByte(byte) for byte in data]
+ with open(s_file, 'w') as fd:
+ print('''/* Auto-generated C program to produce an ELF file for testing */
+
+.section .text
+.code32
+.globl _start
+.type _start, @function
+%s
+_start:
+%s
+.ident "comment"
+
+.comm fred,8,4
+
+.section .empty
+.globl _empty
+_empty:
+.byte 1
+
+.globl ernie
+.data
+.type ernie, @object
+.size ernie, 4
+ernie:
+%s
+''' % ('\n'.join(text_bytes1), '\n'.join(text_bytes2), '\n'.join(data_bytes)),
+ file=fd)
+ lds_file = os.path.join(outdir, 'elf.lds')
+
+ # Use a linker script to set the alignment and text address.
+ with open(lds_file, 'w') as fd:
+ print('''/* Auto-generated linker script to produce an ELF file for testing */
+
+PHDRS
+{
+ text PT_LOAD ;
+ data PT_LOAD ;
+ empty PT_LOAD FLAGS ( 6 ) ;
+ note PT_NOTE ;
+}
+
+SECTIONS
+{
+ . = 0xfef20000;
+ ENTRY(_start)
+ .text . : SUBALIGN(0)
+ {
+ *(.text)
+ } :text
+ .data : {
+ *(.data)
+ } :data
+ _bss_start = .;
+ .empty : {
+ *(.empty)
+ } :empty
+ .note : {
+ *(.comment)
+ } :note
+ .bss _bss_start (OVERLAY) : {
+ *(.bss)
+ }
+}
+''', file=fd)
+ # -static: Avoid requiring any shared libraries
+ # -nostdlib: Don't link with C library
+ # -Wl,--build-id=none: Don't generate a build ID, so that we just get the
+ # text section at the start
+ # -m32: Build for 32-bit x86
+ # -T...: Specifies the link script, which sets the start address
+ stdout = command.Output('cc', '-static', '-nostdlib', '-Wl,--build-id=none',
+ '-m32','-T', lds_file, '-o', elf_fname, s_file)
+ shutil.rmtree(outdir)
+
diff --git a/tools/binman/elf_test.py b/tools/binman/elf_test.py
index 42d94cbbbe2..3172982427d 100644
--- a/tools/binman/elf_test.py
+++ b/tools/binman/elf_test.py
@@ -5,9 +5,12 @@
# Test for the elf module
import os
+import shutil
import sys
+import tempfile
import unittest
+import command
import elf
import test_util
import tools
@@ -136,6 +139,23 @@ class TestElf(unittest.TestCase):
elf.debug = False
self.assertTrue(len(stdout.getvalue()) > 0)
+ def testMakeElf(self):
+ """Test for the MakeElf function"""
+ outdir = tempfile.mkdtemp(prefix='elf.')
+ expected_text = b'1234'
+ expected_data = b'wxyz'
+ elf_fname = os.path.join(outdir, 'elf')
+ bin_fname = os.path.join(outdir, 'elf')
+
+ # Make an Elf file and then convert it to a fkat binary file. This
+ # should produce the original data.
+ elf.MakeElf(elf_fname, expected_text, expected_data)
+ stdout = command.Output('objcopy', '-O', 'binary', elf_fname, bin_fname)
+ with open(bin_fname, 'rb') as fd:
+ data = fd.read()
+ self.assertEqual(expected_text + expected_data, data)
+ shutil.rmtree(outdir)
+
if __name__ == '__main__':
unittest.main()
--
2.22.0.410.gd8fdbe21b5-goog
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