From: Lukas Funke lukas.funke@weidmueller.com
This adds a new etype 'xilinx_fsbl_auth'. Using this etype it is possible to created an authenticated SPL (FSBL in Xilinx terms) for ZynqMP boards.
The etype uses Xilinx Bootgen tools in order to transform the SPL into a bootable image and sign the image with a given primary and seconrady public key. For more information to signing the FSBL please refer to the Xilinx Bootgen documentation.
Here is an example of the etype in use:
spl { filename = "boot.signed.bin";
xilinx_fsbl_auth { psk-filename = "psk0.pem"; ssk-filename = "ssk0.pem"; auth-params = "ppk_select=0", "spk_id=0x00000000";
u_boot_spl_nodtb { }; u_boot_spl_dtb { }; }; };
For this to work the hash of the primary public key has to be fused into the ZynqMP device and authentication (RSA_EN) has to be set.
For testing purposes: if ppk hash check should be skipped one can add the property 'fsbl_config = "bh_auth_enable";' to the etype. However, this should only be used for testing(!).
Signed-off-by: Lukas Funke lukas.funke@weidmueller.com
---
Changes in v2: - Add 'keysrc-enc' property to pass down to Bootgen - Improved documentation - Use predictable output names for intermediated results
tools/binman/entries.rst | 53 ++++++ tools/binman/etype/xilinx_fsbl_auth.py | 213 +++++++++++++++++++++++++ 2 files changed, 266 insertions(+) create mode 100644 tools/binman/etype/xilinx_fsbl_auth.py
diff --git a/tools/binman/entries.rst b/tools/binman/entries.rst index c3c5bda881..98ec3c82a5 100644 --- a/tools/binman/entries.rst +++ b/tools/binman/entries.rst @@ -2462,3 +2462,56 @@ may be used instead.
+.. _etype_xilinx_fsbl_auth: + +Entry: xilinx-fsbl-auth: Authenticated SPL for booting Xilinx ZynqMP devices +---------------------------------------------------------------------------- + +Properties / Entry arguments: + - auth-params: (Optional) Authentication parameters passed to bootgen + - fsbl-config: (Optional) FSBL parameters passed to bootgen + - keysrc-enc: (Optional) Key source when using decryption engine + - pmufw-filename: Filename of PMU firmware. Default: pmu-firmware.elf + - psk-filename: Filename of primary public key + - ssk-filename: Filename of secondary public key + +The following example builds an authenticated boot image. The fuses of +the primary public key (ppk) should be fused together with the RSA_EN flag. + +Example node:: + + spl { + filename = "boot.signed.bin"; + + xilinx-fsbl-auth { + psk-filename = "psk0.pem"; + ssk-filename = "ssk0.pem"; + auth-params = "ppk_select=0", "spk_id=0x00000000"; + + u-boot-spl-nodtb { + }; + u-boot-spl-pubkey-dtb { + algo = "sha384,rsa4096"; + required = "conf"; + key-name = "dev"; + }; + }; + }; + +For testing purposes, e.g. if no RSA_EN should be fused, one could add +the "bh_auth_enable" flag in the fsbl-config field. This will skip the +verification of the ppk fuses and boot the image, even if ppk hash is +invalid. + +Example node:: + + xilinx-fsbl-auth { + psk-filename = "psk0.pem"; + ssk-filename = "ssk0.pem"; + ... + fsbl-config = "bh_auth_enable"; + ... + }; + + + diff --git a/tools/binman/etype/xilinx_fsbl_auth.py b/tools/binman/etype/xilinx_fsbl_auth.py new file mode 100644 index 0000000000..72794ad2bc --- /dev/null +++ b/tools/binman/etype/xilinx_fsbl_auth.py @@ -0,0 +1,213 @@ +# SPDX-License-Identifier: GPL-2.0+ +# Copyright (c) 2023 Weidmueller GmbH +# Written by Lukas Funke lukas.funke@weidmueller.com +# +# Entry-type module for signed ZynqMP boot images (boot.bin) +# + +import tempfile + +from collections import OrderedDict + +from binman import elf +from binman.entry import Entry + +from dtoc import fdt_util + +from u_boot_pylib import tools +from u_boot_pylib import command + +# pylint: disable=C0103 +class Entry_xilinx_fsbl_auth(Entry): + """Authenticated SPL for booting Xilinx ZynqMP devices + + Properties / Entry arguments: + - auth-params: (Optional) Authentication parameters passed to bootgen + - fsbl-config: (Optional) FSBL parameters passed to bootgen + - keysrc-enc: (Optional) Key source when using decryption engine + - pmufw-filename: Filename of PMU firmware. Default: pmu-firmware.elf + - psk-filename: Filename of primary public key + - ssk-filename: Filename of secondary public key + + The following example builds an authenticated boot image. The fuses of + the primary public key (ppk) should be fused together with the RSA_EN flag. + + Example node:: + + spl { + filename = "boot.signed.bin"; + + xilinx-fsbl-auth { + psk-filename = "psk0.pem"; + ssk-filename = "ssk0.pem"; + auth-params = "ppk_select=0", "spk_id=0x00000000"; + + u-boot-spl-nodtb { + }; + u-boot-spl-pubkey-dtb { + algo = "sha384,rsa4096"; + required = "conf"; + key-name = "dev"; + }; + }; + }; + + For testing purposes, e.g. if no RSA_EN should be fused, one could add + the "bh_auth_enable" flag in the fsbl-config field. This will skip the + verification of the ppk fuses and boot the image, even if ppk hash is + invalid. + + Example node:: + + xilinx-fsbl-auth { + psk-filename = "psk0.pem"; + ssk-filename = "ssk0.pem"; + ... + fsbl-config = "bh_auth_enable"; + ... + }; + """ + def __init__(self, section, etype, node): + super().__init__(section, etype, node) + self._auth_params = None + self._entries = OrderedDict() + self._filename = None + self._fsbl_config = None + self._keysrc_enc = None + self._pmufw_filename = None + self._psk_filename = None + self._ssk_filename = None + self.align_default = None + self.bootgen = None + self.required_props = ['psk-filename', 'ssk-filename'] + + def ReadNode(self): + """Read properties from the xilinx_fsbl_auth node""" + super().ReadNode() + self._auth_params = fdt_util.GetStringList(self._node, + 'auth-params') + self._filename = fdt_util.GetString(self._node, 'filename') + self._fsbl_config = fdt_util.GetStringList(self._node, + 'fsbl-config') + self._keysrc_enc = fdt_util.GetString(self._node, + 'keysrc-enc') + self._pmufw_filename = fdt_util.GetString(self._node, + 'pmufw-filename', + 'pmu-firmware.elf') + self._psk_filename = fdt_util.GetString(self._node, 'psk-filename', + 'psk.pem') + self._ssk_filename = fdt_util.GetString(self._node, 'ssk-filename', + 'ssk.pem') + self.ReadEntries() + + def ReadEntries(self): + """Read the subnodes to find out what should go in this image""" + for node in self._node.subnodes: + entry = Entry.Create(self, node) + entry.ReadNode() + self._entries[entry.name] = entry + + @classmethod + def __ToElf(self, data, output_fname): + """ Convert SPL object file to bootable ELF file. + + Args: + data (bytearray): u-boot-spl-nodtb + u-boot-spl-pubkey-dtb obj file + data + output_fname (str): Filename of converted FSBL ELF file + """ + platform_elfflags = [] + + gcc, args = tools.get_target_compile_tool('cc') + args += ['-dumpmachine'] + stdout = command.output(gcc, *args) + # split target machine triplet (arch, vendor, os) + arch, _, _ = stdout.split('-') + + if arch == 'aarch64': + platform_elfflags = ["-B", "aarch64", "-O", "elf64-littleaarch64"] + elif arch == 'x86_64': + # amd64 support makes no sense for the target platform, but we + # include it here to enable testing on hosts + platform_elfflags = ["-B", "i386", "-O", "elf64-x86-64"] + + spl_text_base = hex(elf.GetSymbolAddress( + tools.get_input_filename('spl/u-boot-spl'), ".text")) + + # Obj file to swap data and text section (rename-section) + with tempfile.NamedTemporaryFile(prefix="u-boot-spl-pubkey-", + suffix=".o.tmp", + dir=tools.get_output_dir())\ + as tmp_obj: + input_objcopy_fname = tmp_obj.name + # Align packed content to 4 byte boundary + pad = bytearray(tools.align(len(data), 4) - len(data)) + tools.write_file(input_objcopy_fname, data + pad) + # Final output elf file which contains a valid start address + with tempfile.NamedTemporaryFile(prefix="u-boot-spl-pubkey-elf-", + suffix=".o.tmp", + dir=tools.get_output_dir())\ + as tmp_elf_obj: + input_ld_fname = tmp_elf_obj.name + objcopy, args = tools.get_target_compile_tool('objcopy') + args += ["--rename-section", ".data=.text", + "-I", "binary"] + args += platform_elfflags + args += [input_objcopy_fname, input_ld_fname] + command.run(objcopy, *args) + + ld, args = tools.get_target_compile_tool('ld') + args += [input_ld_fname, '-o', output_fname, + "--defsym", f"_start={spl_text_base}", + "-Ttext", spl_text_base] + command.run(ld, *args) + + def ObtainContents(self, skip_entry=None, fake_size=0): + """ Pack node content, and create bootable, signed ZynqMP boot image + + The method collects the content of this node (usually SPL + dtb) and + converts them to an ELF file. The ELF file is passed to the + Xilinx bootgen tool which packs the SPL ELF file together with + Platform Management Unit (PMU) firmware into a bootable image + for ZynqMP devices. The image is signed within this step. + + The result is a bootable, authenticated SPL image for Xilinx ZynqMP + devices. + + """ + bootbin_fname = self._filename if self._filename else \ + tools.get_output_filename( + f'boot.{self.GetUniqueName()}.bin') + + pmufw_elf_fname = tools.get_input_filename(self._pmufw_filename) + psk_fname = tools.get_input_filename(self._psk_filename) + ssk_fname = tools.get_input_filename(self._ssk_filename) + fsbl_config = ";".join(self._fsbl_config) if self._fsbl_config else None + auth_params = ";".join(self._auth_params) if self._auth_params else None + + spl_elf_fname = tools.get_output_filename('u-boot-spl-pubkey.dtb.elf') + + # Collect node contents. This is usually the SPL concatenated + # with the SPL dtb (device tree). + data, _, _ = self.collect_contents_to_file( + self._entries.values(), 'spl') + + # We need to convert to node content (see above) into an ELF + # file in order to be processed by bootgen. + self.__ToElf(bytearray(data), spl_elf_fname) + + # Call Bootgen in order to sign the SPL + self.bootgen.sign('zynqmp', spl_elf_fname, pmufw_elf_fname, + psk_fname, ssk_fname, fsbl_config, + auth_params, self._keysrc_enc, bootbin_fname) + + self.SetContents(tools.read_file(bootbin_fname)) + + return True + + # pylint: disable=C0116 + def AddBintools(self, btools): + super().AddBintools(btools) + for entry in self._entries.values(): + entry.AddBintools(btools) + self.bootgen = self.AddBintool(btools, 'bootgen')