Re: [U-Boot] [PATCH v2 1/2] rockchip: make_fit_atf.py: Eliminate pyelftools dependency

Hi Chris:

On 7/14/19 4:46 PM, Chris Webb wrote:

make_fit_aft.py depends on the non-standard library pyelftools to pull out PT_LOAD segments from ELF files. However, this is as easy to do manually, without imposing the extra dependency on users.

Structures in the ELF file are unpacked into variables named to exactly match the ELF spec to ensure the destructuring code is reasonably self-documenting.

Signed-off-by: Chris Webb chris@arachsys.com

arch/arm/mach-rockchip/make_fit_atf.py | 75 +++++++++++--------------- 1 file changed, 32 insertions(+), 43 deletions(-)

diff --git a/arch/arm/mach-rockchip/make_fit_atf.py b/arch/arm/mach-rockchip/make_fit_atf.py index db0ae96ca8..9acc1edfc6 100755 --- a/arch/arm/mach-rockchip/make_fit_atf.py +++ b/arch/arm/mach-rockchip/make_fit_atf.py @@ -13,16 +13,7 @@ import os import sys import getopt import logging

-# pip install pyelftools -from elftools.elf.elffile import ELFFile

-ELF_SEG_P_TYPE = 'p_type' -ELF_SEG_P_PADDR = 'p_paddr' -ELF_SEG_P_VADDR = 'p_vaddr' -ELF_SEG_P_OFFSET = 'p_offset' -ELF_SEG_P_FILESZ = 'p_filesz' -ELF_SEG_P_MEMSZ = 'p_memsz' +import struct

DT_HEADER = """ /* @@ -118,33 +109,19 @@ def append_conf_node(file, dtbs, segments): file.write('\n')

def generate_atf_fit_dts_uboot(fit_file, uboot_file_name):

• num_load_seg = 0
• p_paddr = 0xFFFFFFFF
• with open(uboot_file_name, 'rb') as uboot_file:

•    uboot = ELFFile(uboot_file)
  

•    for i in range(uboot.num_segments()):
  

•        seg = uboot.get_segment(i)
  

•        if seg.__getitem__(ELF_SEG_P_TYPE) == 'PT_LOAD':
  

•            p_paddr = seg.__getitem__(ELF_SEG_P_PADDR)
  

•            num_load_seg = num_load_seg + 1
  

• assert (p_paddr != 0xFFFFFFFF and num_load_seg == 1)

• segments = unpack_elf(uboot_file_name)

• if len(segments) != 1:

•    raise ValueError("Invalid u-boot ELF image '%s'" % uboot_file_name)
  

• index, entry, p_paddr, data = segments[0] fit_file.write(DT_UBOOT % p_paddr)

  def generate_atf_fit_dts_bl31(fit_file, bl31_file_name, dtbs_file_name):

• with open(bl31_file_name, 'rb') as bl31_file:

•    bl31 = ELFFile(bl31_file)
  

•    elf_entry = bl31.header['e_entry']
  

•    segments = bl31.num_segments()
  

•    for i in range(segments):
  

•        seg = bl31.get_segment(i)
  

•        if seg.__getitem__(ELF_SEG_P_TYPE) == 'PT_LOAD':
  

•            paddr = seg.__getitem__(ELF_SEG_P_PADDR)
  

•            append_bl31_node(fit_file, i + 1, paddr, elf_entry)
  

• segments = unpack_elf(bl31_file_name)
• for index, entry, paddr, data in segments:

•    append_bl31_node(fit_file, index + 1, paddr, entry)
  append_fdt_node(fit_file, dtbs_file_name)
  fit_file.write(DT_IMAGES_NODE_END)
  

• append_conf_node(fit_file, dtbs_file_name, segments)

• append_conf_node(fit_file, dtbs_file_name, len(segments))

  def generate_atf_fit_dts(fit_file_name, bl31_file_name, uboot_file_name, dtbs_file_name): # Generate FIT script for ATF image.

@@ -162,17 +139,29 @@ def generate_atf_fit_dts(fit_file_name, bl31_file_name, uboot_file_name, dtbs_fi fit_file.close()

def generate_atf_binary(bl31_file_name):

• with open(bl31_file_name, 'rb') as bl31_file:

•    bl31 = ELFFile(bl31_file)
  

•    num = bl31.num_segments()
  

•    for i in range(num):
  

•        seg = bl31.get_segment(i)
  

•        if seg.__getitem__(ELF_SEG_P_TYPE) == 'PT_LOAD':
  

•            paddr = seg.__getitem__(ELF_SEG_P_PADDR)
  

•            file_name = 'bl31_0x%08x.bin' % paddr
  

•            with open(file_name, "wb") as atf:
  

•                atf.write(seg.data())
  

• for index, entry, paddr, data in unpack_elf(bl31_file_name):

•    file_name = 'bl31_0x%08x.bin' % paddr
  

•    with open(file_name, "wb") as atf:
  

•        atf.write(data)
  

+def unpack_elf(filename):

• with open(filename, 'rb') as file:

•    elf = file.read()
  

• if elf[0:7] != b'\x7fELF\x02\x01\x01' or elf[18:20] != b'\xb7\x00':

•    raise ValueError("Invalid arm64 ELF file '%s'" % filename)
  

• e_entry, e_phoff = struct.unpack_from('<2Q', elf, 0x18)
• e_phentsize, e_phnum = struct.unpack_from('<2H', elf, 0x36)
• segments = []
• for index in range(e_phnum):

•    offset = e_phoff + e_phentsize*index
  

One small coding style issue:

offset = e_phoff + e_phentsize * index

•    p_type, p_flags, p_offset = struct.unpack_from('<LLQ', elf, offset)
  

•    if p_type == 1: # PT_LOAD
  

•        p_paddr, p_filesz = struct.unpack_from('<2Q', elf, offset + 0x18)
  

•        p_data = elf[p_offset:p_offset + p_filesz]
  

•        segments.append((index, e_entry, p_paddr, p_data))
  

• return segments

  def main(): uboot_elf = "./u-boot"