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author | 2023-10-10 14:33:42 +0000 | |
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committer | 2023-10-10 14:33:42 +0000 | |
commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/u-boot/tools/binman/elf.py | |
parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/u-boot/tools/binman/elf.py')
-rw-r--r-- | roms/u-boot/tools/binman/elf.py | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/roms/u-boot/tools/binman/elf.py b/roms/u-boot/tools/binman/elf.py new file mode 100644 index 000000000..03b49d716 --- /dev/null +++ b/roms/u-boot/tools/binman/elf.py @@ -0,0 +1,303 @@ +# SPDX-License-Identifier: GPL-2.0+ +# Copyright (c) 2016 Google, Inc +# Written by Simon Glass <sjg@chromium.org> +# +# Handle various things related to ELF images +# + +from collections import namedtuple, OrderedDict +import io +import os +import re +import shutil +import struct +import tempfile + +from patman import command +from patman import tools +from patman import tout + +ELF_TOOLS = True +try: + from elftools.elf.elffile import ELFFile + from elftools.elf.sections import SymbolTableSection +except: # pragma: no cover + ELF_TOOLS = False + +Symbol = namedtuple('Symbol', ['section', 'address', 'size', 'weak']) + +# Information about an ELF file: +# data: Extracted program contents of ELF file (this would be loaded by an +# ELF loader when reading this file +# load: Load address of code +# entry: Entry address of code +# memsize: Number of bytes in memory occupied by loading this ELF file +ElfInfo = namedtuple('ElfInfo', ['data', 'load', 'entry', 'memsize']) + + +def GetSymbols(fname, patterns): + """Get the symbols from an ELF file + + Args: + fname: Filename of the ELF file to read + patterns: List of regex patterns to search for, each a string + + Returns: + None, if the file does not exist, or Dict: + key: Name of symbol + value: Hex value of symbol + """ + stdout = tools.Run('objdump', '-t', fname) + lines = stdout.splitlines() + if patterns: + re_syms = re.compile('|'.join(patterns)) + else: + re_syms = None + syms = {} + syms_started = False + for line in lines: + if not line or not syms_started: + if 'SYMBOL TABLE' in line: + syms_started = True + line = None # Otherwise code coverage complains about 'continue' + continue + if re_syms and not re_syms.search(line): + continue + + space_pos = line.find(' ') + value, rest = line[:space_pos], line[space_pos + 1:] + flags = rest[:7] + parts = rest[7:].split() + section, size = parts[:2] + if len(parts) > 2: + name = parts[2] if parts[2] != '.hidden' else parts[3] + syms[name] = Symbol(section, int(value, 16), int(size,16), + flags[1] == 'w') + + # Sort dict by address + return OrderedDict(sorted(syms.items(), key=lambda x: x[1].address)) + +def GetSymbolAddress(fname, sym_name): + """Get a value of a symbol from an ELF file + + Args: + fname: Filename of the ELF file to read + patterns: List of regex patterns to search for, each a string + + Returns: + Symbol value (as an integer) or None if not found + """ + syms = GetSymbols(fname, [sym_name]) + sym = syms.get(sym_name) + if not sym: + return None + return sym.address + +def LookupAndWriteSymbols(elf_fname, entry, section): + """Replace all symbols in an entry with their correct values + + The entry contents is updated so that values for referenced symbols will be + visible at run time. This is done by finding out the symbols offsets in the + entry (using the ELF file) and replacing them with values from binman's data + structures. + + Args: + elf_fname: Filename of ELF image containing the symbol information for + entry + entry: Entry to process + section: Section which can be used to lookup symbol values + """ + fname = tools.GetInputFilename(elf_fname) + syms = GetSymbols(fname, ['image', 'binman']) + if not syms: + return + base = syms.get('__image_copy_start') + if not base: + return + for name, sym in syms.items(): + if name.startswith('_binman'): + msg = ("Section '%s': Symbol '%s'\n in entry '%s'" % + (section.GetPath(), name, entry.GetPath())) + offset = sym.address - base.address + if offset < 0 or offset + sym.size > entry.contents_size: + raise ValueError('%s has offset %x (size %x) but the contents ' + 'size is %x' % (entry.GetPath(), offset, + sym.size, entry.contents_size)) + if sym.size == 4: + pack_string = '<I' + elif sym.size == 8: + pack_string = '<Q' + else: + raise ValueError('%s has size %d: only 4 and 8 are supported' % + (msg, sym.size)) + + # Look up the symbol in our entry tables. + value = section.GetImage().LookupImageSymbol(name, sym.weak, msg, + base.address) + if value is None: + value = -1 + pack_string = pack_string.lower() + value_bytes = struct.pack(pack_string, value) + tout.Debug('%s:\n insert %s, offset %x, value %x, length %d' % + (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' % byte for byte in text[:2]] + text_bytes2 = ['\t.byte\t%#x' % byte for byte in text[2:]] + data_bytes = ['\t.byte\t%#x' % 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 + /DISCARD/ : { + *(.note.gnu.property) + } + .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 + cc, args = tools.GetTargetCompileTool('cc') + args += ['-static', '-nostdlib', '-Wl,--build-id=none', '-m32', '-T', + lds_file, '-o', elf_fname, s_file] + stdout = command.Output(cc, *args) + shutil.rmtree(outdir) + +def DecodeElf(data, location): + """Decode an ELF file and return information about it + + Args: + data: Data from ELF file + location: Start address of data to return + + Returns: + ElfInfo object containing information about the decoded ELF file + """ + file_size = len(data) + with io.BytesIO(data) as fd: + elf = ELFFile(fd) + data_start = 0xffffffff; + data_end = 0; + mem_end = 0; + virt_to_phys = 0; + + for i in range(elf.num_segments()): + segment = elf.get_segment(i) + if segment['p_type'] != 'PT_LOAD' or not segment['p_memsz']: + skipped = 1 # To make code-coverage see this line + continue + start = segment['p_paddr'] + mend = start + segment['p_memsz'] + rend = start + segment['p_filesz'] + data_start = min(data_start, start) + data_end = max(data_end, rend) + mem_end = max(mem_end, mend) + if not virt_to_phys: + virt_to_phys = segment['p_paddr'] - segment['p_vaddr'] + + output = bytearray(data_end - data_start) + for i in range(elf.num_segments()): + segment = elf.get_segment(i) + if segment['p_type'] != 'PT_LOAD' or not segment['p_memsz']: + skipped = 1 # To make code-coverage see this line + continue + start = segment['p_paddr'] + offset = 0 + if start < location: + offset = location - start + start = location + # A legal ELF file can have a program header with non-zero length + # but zero-length file size and a non-zero offset which, added + # together, are greater than input->size (i.e. the total file size). + # So we need to not even test in the case that p_filesz is zero. + # Note: All of this code is commented out since we don't have a test + # case for it. + size = segment['p_filesz'] + #if not size: + #continue + #end = segment['p_offset'] + segment['p_filesz'] + #if end > file_size: + #raise ValueError('Underflow copying out the segment. File has %#x bytes left, segment end is %#x\n', + #file_size, end) + output[start - data_start:start - data_start + size] = ( + segment.data()[offset:]) + return ElfInfo(output, data_start, elf.header['e_entry'] + virt_to_phys, + mem_end - data_start) |