1 | .. SPDX-License-Identifier: CC-BY-SA-4.0 |
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2 | |
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3 | .. Copyright (C) 2018 Chris Johns <chrisj@rtems.org> |
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4 | |
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5 | TFTP and U-Boot |
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6 | --------------- |
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7 | |
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8 | .. index:: TFTP, U-Boot, Testing |
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9 | |
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10 | TFTP and U-Boot provides a simple way to test RTEMS on a network capable |
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11 | target. The RTEMS Tester starts a TFTP server for each test and the target's |
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12 | boot monitor, in this case U-Boot request a file, any file, which the TFTP |
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13 | server supplies. U-Boot loads the executable and boots it using a standard |
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14 | U-Boot script. |
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15 | |
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16 | .. _fig-tester-tftp-u-boot: |
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17 | |
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18 | .. figure:: ../../images/user/test-tftp.png |
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19 | :width: 35% |
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20 | :alt: RTEMS Tester using TFTP and U-Boot |
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21 | :figclass: align-center |
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22 | |
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23 | RTEMS Tester using TFTP and U-Boot. |
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24 | |
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25 | The Figure :ref:`fig-tester-tftp-u-boot` figure shows the structure and |
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26 | control flow of the RTEMS Tester using TFTP and U-boot. The executables are |
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27 | built and the ``rtems-test`` command is run from the top of the build |
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28 | directory. |
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29 | |
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30 | This test mode can only support a single test job running at once. You cannot |
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31 | add more test target hardware and run the tests in parallel. |
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32 | |
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33 | Target Hardware |
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34 | ^^^^^^^^^^^^^^^ |
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35 | |
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36 | The RTEMS Tester TFTP and U-Boot method of testing requires: |
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37 | |
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38 | #. A target with network interface. |
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39 | |
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40 | #. U-Boot, iPXE or similar boot loader with network driver support for your |
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41 | target hardware and support for the TFTP protocol. |
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42 | |
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43 | #. Network power of IO switch. |
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44 | |
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45 | #. Network DHCP server. |
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46 | |
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47 | #. Console interface cable that matches your target's console UART interface. |
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48 | |
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49 | #. Telnet terminal server. See :ref:`TesterConsoles`. |
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50 | |
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51 | The network power or IO switch is a device that can control power or an IO pin |
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52 | over a network connection using a script-able protocol such as Telnet or |
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53 | curl. This device can be used with the target control commands. |
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54 | |
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55 | U-Boot Set Up |
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56 | ~~~~~~~~~~~~~ |
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57 | |
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58 | Obtain a working image of the U-Boot boot loader for your target. We suggest |
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59 | you follow the instructions for you target. |
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60 | |
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61 | Configure U-Boot to network boot using the TFTP protocol. This is U-Boot script |
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62 | for a Zedboard: |
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63 | |
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64 | .. code-block:: shell |
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65 | |
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66 | loadaddr=0x02000000 |
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67 | uenvcmd=echo Booting RTEMS Zed from net; set autoload no; dhcp; set serverip 10.10.5.2; tftpboot zed/rtems.img; bootm; reset; |
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68 | |
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69 | The load address variable ``loadaddr`` is specific to the Zedboard and can be |
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70 | found in the various examples scripts on the internet. The script then sets |
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71 | U-Boot environment variable ``autoload`` to ``no`` causing DHCP to only request |
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72 | a DHCP lease from the DHCP server. The script sets the ``serverip`` to the host |
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73 | that will be running the RTEMS Tester then issues a TFTP request. The file name |
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74 | can be anything because the RTEMS Tester ignores it sending the executable |
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75 | image under test. Finally the script boots the download executable and if that |
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76 | fails the catch all ``reset`` resets the board and starts the boot process |
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77 | over. |
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78 | |
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79 | Test the target boots and U-Boot runs and obtains a valid DHCP lease. Manually |
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80 | connect the console's telnet port. |
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81 | |
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82 | BSP Configuration |
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83 | ^^^^^^^^^^^^^^^^^ |
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84 | |
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85 | The BSP's configuration file must contain the standard fields: |
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86 | |
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87 | - ``bsp`` |
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88 | - ``arch`` |
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89 | - ``jobs`` - Must be set to ``1``. |
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90 | - ``tester`` - Set to ``%{_rtscripts}/tftp.cfg`` |
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91 | |
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92 | For example the Zedboard's configuration is: |
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93 | |
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94 | .. code-block:: ini |
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95 | |
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96 | [xilinx_zynq_zedboard] |
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97 | bsp = xilinx_zynq_zedboard |
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98 | arch = arm |
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99 | jobs = 1 |
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100 | tester = %{_rtscripts}/tftp.cfg |
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101 | |
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102 | The TFTP configuration supports the following field's: |
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103 | |
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104 | ``bsp_tty_dev`` |
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105 | The target's tty console. For telnet this is a host and port pair written in |
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106 | the standard networking format, for example ``serserver:12345``. |
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107 | |
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108 | ``test_restarts`` |
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109 | The number of restarts before the test is considered ``invalid``. |
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110 | |
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111 | ``target_reset_regex`` |
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112 | The target reset regular expression. This is a `Python regular expression |
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113 | <https://docs.python.org/2/library/re.html#regular-expression-syntax>`_ used |
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114 | to filter the console input. If a match is made something has happened during |
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115 | the boot process that requires a reset. The ``target_reset_command`` |
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116 | is issued to perform the reset. This field is typically looks for boot loader |
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117 | error messages that indicate the boot process as failed. |
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118 | |
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119 | ``target_start_regex`` |
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120 | The target start regular expression. This also a Python regular expression to |
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121 | filter the console input to detect if a target has reset. If a board crashes |
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122 | running a test or at any point in time and reset this filter detects this as |
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123 | happened and end the test with a suitable result. |
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124 | |
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125 | ``target_on_command`` |
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126 | The target on command is a host shell command that is called before the first |
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127 | test. This command powers on a target. Targets should be left powered off |
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128 | when not running tests or the target may request TFTP downloads that are for |
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129 | another target interfering with those test results. We recommend you |
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130 | implement this command as a target off command, a pause, then a target on |
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131 | command. |
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132 | |
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133 | ``target_off_command`` |
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134 | The target off command is a host shell command that is called after the last |
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135 | test powering off the target. |
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136 | |
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137 | ``target_reset_command`` |
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138 | The target reset command is a host shell command that is called when the |
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139 | target needs to be reset. This command can power cycle the target or toggle a |
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140 | reset signal connected to the target. If you are power cycling a target make |
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141 | sure you have a suitable pause to let the target completely power down. |
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142 | |
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143 | ``target_pretest_command`` |
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144 | The target pretest command is a host shell comment that is called before the |
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145 | test is run |
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146 | |
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147 | The commands in the listed fields can include parameters that are |
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148 | substituted. The parameters are: |
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149 | |
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150 | ``@ARCH@`` |
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151 | The BSP architecture |
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152 | |
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153 | ``@BSP@`` |
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154 | The BSP's name |
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155 | |
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156 | ``@EXE@`` |
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157 | The executable name. |
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158 | |
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159 | ``@FEXE@`` |
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160 | The |
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161 | . The |
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162 | ``@ARCH`` is the |
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163 | |
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164 | substituted |
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165 | |
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166 | Some of these field are normally provided by a user's configuration. To do this |
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167 | use: |
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168 | |
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169 | .. code-block:: shell |
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170 | |
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171 | requires = bsp_tty_dev, target_on_command, target_off_command, target_reset_command |
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172 | |
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173 | The ``requires`` value requires the user provide these settings in their |
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174 | configuration file. |
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175 | |
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176 | The Zedboard's configuration file is: |
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177 | |
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178 | .. code-block:: ini |
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179 | |
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180 | [xilinx_zynq_zedboard] |
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181 | bsp = xilinx_zynq_zedboard |
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182 | arch = arm |
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183 | jobs = 1 |
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184 | tester = %{_rtscripts}/tftp.cfg |
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185 | test_restarts = 3 |
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186 | target_reset_regex = ^No ethernet found.*|^BOOTP broadcast 6.*|^.+complete\.+ TIMEOUT.* |
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187 | target_start_regex = ^U-Boot SPL .* |
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188 | requires = target_on_command, target_off_command, target_reset_command, bsp_tty_dev |
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189 | |
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190 | The ``target_start_regex`` searches for U-Boot's first console message. This |
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191 | indicate the board can restarted. |
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192 | |
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193 | The ``target_reset_regex`` checks if no ethernet interface is found. This can |
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194 | happen if U-Boot cannot detect the PHY device. It also checks if too many DHCP |
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195 | requests happen and finally a check is made for any timeouts reported by |
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196 | U-Boot. |
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197 | |
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198 | An example of a user configuration for the Zedboard is: |
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199 | |
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200 | .. code-block:: ini |
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201 | |
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202 | [xilinx_zynq_zedboard] |
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203 | bsp_tty_dev = selserver:12345 |
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204 | target_pretest_command = zynq-mkimg @EXE@ |
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205 | target_exe_filter = /\.exe/.exe.img/ |
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206 | target_on_command = power-ctl toggle-on 1 4 |
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207 | target_off_command = power-ctl off 1 |
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208 | target_reset_command = power-ctl toggle-on 1 3 |
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209 | |
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210 | TFTP Sequences |
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211 | ^^^^^^^^^^^^^^ |
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212 | |
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213 | Running a large number of tests on real hardware exposes a range of issues and |
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214 | RTEMS Tester is designed to be tolerant of failures in booting or loading that |
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215 | can happen, for example a hardware design. These sequence diagrams document |
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216 | some of the sequences that can occur when errors happen. |
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217 | |
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218 | The simplest sequence is running a test. The target is powered on, the test is |
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219 | loaded and executed and a pass or fail is determined: |
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220 | |
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221 | .. _fig-tester-tftp-seq-1: |
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222 | |
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223 | .. figure:: ../../images/user/test-tftp-seq-1.png |
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224 | :width: 90% |
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225 | :alt: Test Pass and Fail Sequence |
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226 | :figclass: align-center |
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227 | |
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228 | Test Pass and Fail Sequences |
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229 | |
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230 | The target start filter triggers if a start condition is detected. This can |
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231 | happen if the board crashes or resets with no output. If this happens |
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232 | repeatedly the test result is invalid: |
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233 | |
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234 | .. _fig-tester-tftp-seq-2: |
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235 | |
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236 | .. figure:: ../../images/user/test-tftp-seq-2.png |
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237 | :width: 80% |
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238 | :alt: Target Start Filter Trigger |
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239 | :figclass: align-center |
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240 | |
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241 | Target Start Filter Trigger |
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242 | |
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243 | The reset filter triggers if an error condition is found such as the bootloader |
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244 | not being able to load the test executable. If the filter triggers the |
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245 | ``target_reset_command`` is run: |
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246 | |
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247 | .. _fig-tester-tftp-seq-3: |
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248 | |
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249 | .. figure:: ../../images/user/test-tftp-seq-3.png |
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250 | :width: 50% |
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251 | :alt: Target Reset Filter Trigger |
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252 | :figclass: align-center |
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253 | |
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254 | Target Reset Filter Trigger |
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255 | |
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256 | If the RTEMS Tester does not detect a test has started it can restart the test |
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257 | by resetting the target. The reset command can toggle an IO pin connected to |
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258 | reset, request a JTAG pod issue a reset or turn the power off and on: |
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259 | |
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260 | .. _fig-tester-tftp-seq-4: |
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261 | |
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262 | .. figure:: ../../images/user/test-tftp-seq-4.png |
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263 | :width: 60% |
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264 | :alt: Target Timeout |
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265 | :figclass: align-center |
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266 | |
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267 | Target Timeout |
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