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Diffstat (limited to 'cxmanage_api/ubootenv.py')
| -rw-r--r-- | cxmanage_api/ubootenv.py | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/cxmanage_api/ubootenv.py b/cxmanage_api/ubootenv.py new file mode 100644 index 0000000..b5b8272 --- /dev/null +++ b/cxmanage_api/ubootenv.py @@ -0,0 +1,255 @@ +# Copyright (c) 2012, Calxeda Inc. +# +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# * Redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in the +# documentation and/or other materials provided with the distribution. +# * Neither the name of Calxeda Inc. nor the names of its contributors +# may be used to endorse or promote products derived from this software +# without specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS +# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE +# COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, +# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS +# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR +# TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF +# THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH +# DAMAGE. + + +import struct + +from cxmanage_api.simg import has_simg, get_simg_contents +from cxmanage_api.crc32 import get_crc32 +from cxmanage_api.cx_exceptions import UnknownBootCmdError + + +ENVIRONMENT_SIZE = 8192 +UBOOTENV_V1_VARIABLES = ["bootcmd_default", "bootcmd_sata", "bootcmd_pxe", + "bootdevice"] +UBOOTENV_V2_VARIABLES = ["bootcmd0", "init_scsi", "bootcmd_scsi", "init_pxe", + "bootcmd_pxe", "devnum"] + + +class UbootEnv: + """Represents a U-Boot Environment. + + >>> from cxmanage_api.ubootenv import UbootEnv + >>> uboot = UbootEnv() + + :param contents: UBootEnvironment contnents. + :type contents: string + + """ + + def __init__(self, contents=None): + """Default constructor for the UbootEnv class.""" + self.variables = {} + + if (contents != None): + if (has_simg(contents)): + contents = get_simg_contents(contents) + + contents = contents.rstrip("%c%c" % (chr(0), chr(255)))[4:] + lines = contents.split(chr(0)) + for line in lines: + part = line.partition("=") + self.variables[part[0]] = part[2] + + def set_boot_order(self, boot_args): + """Sets the boot order specified in the uboot environment. + + >>> uboot.set_boot_order(boot_args=['disk', 'pxe']) + + .. note:: + * Valid Args: + pxe - boot from pxe server\n + disk - boot from default sata device\n + diskX - boot from sata device X\n + diskX:Y - boot from sata device X, partition Y\n + retry - retry last boot device indefinitely\n + reset - reset A9\n + + :param boot_args: Boot args (boot order). A list of strings. + :type boot_args: list + + :raises ValueError: If an invalid boot device is specified. + :raises ValueError: If 'retry' and 'reset' args are used together. + :raises Exception: If the u-boot environment is unrecognized + + """ + validate_boot_args(boot_args) + if boot_args == self.get_boot_order(): + return + + commands = [] + retry = False + reset = False + + if all(x in self.variables for x in UBOOTENV_V1_VARIABLES): + version = 1 + elif all(x in self.variables for x in UBOOTENV_V2_VARIABLES): + version = 2 + else: + raise Exception("Unrecognized u-boot environment") + + for arg in boot_args: + if arg == "retry": + retry = True + elif arg == "reset": + reset = True + elif version == 1: + if arg == "pxe": + commands.append("run bootcmd_pxe") + elif arg == "disk": + commands.append("run bootcmd_sata") + elif arg.startswith("disk"): + try: + dev, part = map(int, arg[4:].split(":")) + bootdevice = "%i:%i" % (dev, part) + except ValueError: + bootdevice = str(int(arg[4:])) + commands.append("setenv bootdevice %s && run bootcmd_sata" + % bootdevice) + elif version == 2: + if arg == "pxe": + commands.append("run init_pxe && run bootcmd_pxe") + elif arg == "disk": + commands.append("run init_scsi && run bootcmd_scsi") + elif arg.startswith("disk"): + try: + dev, part = map(int, arg[4:].split(":")) + bootdevice = "%i:%i" % (dev, part) + except ValueError: + bootdevice = str(int(arg[4:])) + commands.append( + "setenv devnum %s && run init_scsi && run bootcmd_scsi" + % bootdevice) + + if retry and reset: + raise ValueError("retry and reset are mutually exclusive") + elif retry: + commands[-1] = "while true\ndo\n%s\nsleep 1\ndone" % commands[-1] + elif reset: + commands.append("reset") + + if version == 1: + self.variables["bootcmd_default"] = "; ".join(commands) + else: + self.variables["bootcmd0"] = "; ".join(commands) + + def get_boot_order(self): + """Gets the boot order specified in the uboot environment. + + >>> uboot.get_boot_order() + ['disk', 'pxe'] + + :returns: Boot order for this U-Boot Environment. + :rtype: string + + :raises UnknownBootCmdError: If a boot command is unrecognized. + + """ + boot_args = [] + + if self.variables["bootcmd0"] == "run boot_iter": + for target in self.variables["boot_targets"].split(): + if target == "pxe": + boot_args.append("pxe") + elif target == "scsi": + boot_args.append("disk") + else: + raise UnknownBootCmdError("Unrecognized boot target: %s" + % target) + else: + if "bootcmd_default" in self.variables: + commands = self.variables["bootcmd_default"].split("; ") + else: + commands = self.variables["bootcmd0"].split("; ") + + retry = False + for command in commands: + if command.startswith("while true"): + retry = True + command = command.split("\n")[2] + + if command in ["run bootcmd_pxe", + "run init_pxe && run bootcmd_pxe"]: + boot_args.append("pxe") + elif command in ["run bootcmd_sata", + "run init_scsi && run bootcmd_scsi"]: + boot_args.append("disk") + elif (command.startswith("setenv bootdevice") or + command.startswith("setenv devnum")): + boot_args.append("disk%s" % command.split()[2]) + elif (command == "reset"): + boot_args.append("reset") + break + else: + raise UnknownBootCmdError("Unrecognized boot command: %s" + % command) + + if retry: + boot_args.append("retry") + break + + if not boot_args: + boot_args = ["none"] + + validate_boot_args(boot_args) # sanity check + return boot_args + + def get_contents(self): + """Returns a raw string representation of the uboot environment. + + >>> uboot.get_contents() + 'j4\x88\xb7bootcmd_default=run bootcmd_sata; run bootcmd_pxe ... ' + >>> # + >>> # Output trimmed for brevity ... + >>> # + + :returns: Raw string representation of the UBoot Environment. + :rtype: string + + """ + contents = "" + # Add variables + for variable in self.variables: + contents += "%s=%s\0" % (variable, self.variables[variable]) + contents += "\0" + # Add padding to end + contents += "".join([chr(255) + for _ in range(ENVIRONMENT_SIZE - len(contents) - 4)]) + # Add crc32 to beginning + crc32 = get_crc32(contents, 0xFFFFFFFF) ^ 0xFFFFFFFF + contents = struct.pack("<I", crc32) + contents + return contents + + +def validate_boot_args(boot_args): + """ Validate boot arguments. Raises a ValueError if the args are invalid.""" + for arg in boot_args: + if arg in ["retry", "reset", "pxe", "disk", "none"]: + continue + elif arg.startswith("disk"): + try: + map(int, arg[4:].split(":")) + except ValueError: + try: + int(arg[4:]) + except ValueError: + raise ValueError("Invalid boot arg: %s" % arg) + else: + raise ValueError("Invalid boot arg: %s" % arg) |