sandbox.rst 17 KB

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  1. .. SPDX-License-Identifier: GPL-2.0+ */
  2. .. Copyright (c) 2014 The Chromium OS Authors.
  3. .. sectionauthor:: Simon Glass <sjg@chromium.org>
  4. Sandbox
  5. =======
  6. Native Execution of U-Boot
  7. --------------------------
  8. The 'sandbox' architecture is designed to allow U-Boot to run under Linux on
  9. almost any hardware. To achieve this it builds U-Boot (so far as possible)
  10. as a normal C application with a main() and normal C libraries.
  11. All of U-Boot's architecture-specific code therefore cannot be built as part
  12. of the sandbox U-Boot. The purpose of running U-Boot under Linux is to test
  13. all the generic code, not specific to any one architecture. The idea is to
  14. create unit tests which we can run to test this upper level code.
  15. Sandbox allows development of many types of new features in a traditional way,
  16. rather than needing to test each iteration on real hardware. Many U-Boot
  17. features were developed on sandbox, including the core driver model, most
  18. uclasses, verified boot, bloblist, logging and dozens of others. Sandbox has
  19. enabled many large-scale code refactors as well.
  20. CONFIG_SANDBOX is defined when building a native board.
  21. The board name is 'sandbox' but the vendor name is unset, so there is a
  22. single board in board/sandbox.
  23. CONFIG_SANDBOX_BIG_ENDIAN should be defined when running on big-endian
  24. machines.
  25. There are two versions of the sandbox: One using 32-bit-wide integers, and one
  26. using 64-bit-wide integers. The 32-bit version can be build and run on either
  27. 32 or 64-bit hosts by either selecting or deselecting CONFIG_SANDBOX_32BIT; by
  28. default, the sandbox it built for a 32-bit host. The sandbox using 64-bit-wide
  29. integers can only be built on 64-bit hosts.
  30. Note that standalone/API support is not available at present.
  31. Prerequisites
  32. -------------
  33. Install the dependencies noted in :doc:`../build/gcc`.
  34. Basic Operation
  35. ---------------
  36. To run sandbox U-Boot use something like::
  37. make sandbox_defconfig all
  38. ./u-boot
  39. Note: If you get errors about 'sdl-config: Command not found' you may need to
  40. install libsdl2.0-dev or similar to get SDL support. Alternatively you can
  41. build sandbox without SDL (i.e. no display/keyboard support) by removing
  42. the CONFIG_SANDBOX_SDL line in include/configs/sandbox.h or using::
  43. make sandbox_defconfig all NO_SDL=1
  44. ./u-boot
  45. U-Boot will start on your computer, showing a sandbox emulation of the serial
  46. console::
  47. U-Boot 2014.04 (Mar 20 2014 - 19:06:00)
  48. DRAM: 128 MiB
  49. Using default environment
  50. In: serial
  51. Out: lcd
  52. Err: lcd
  53. =>
  54. You can issue commands as your would normally. If the command you want is
  55. not supported you can add it to include/configs/sandbox.h.
  56. To exit, type 'poweroff' or press Ctrl-C.
  57. Console / LCD support
  58. ---------------------
  59. Assuming that CONFIG_SANDBOX_SDL is defined when building, you can run the
  60. sandbox with LCD and keyboard emulation, using something like::
  61. ./u-boot -d u-boot.dtb -l
  62. This will start U-Boot with a window showing the contents of the LCD. If
  63. that window has the focus then you will be able to type commands as you
  64. would on the console. You can adjust the display settings in the device
  65. tree file - see arch/sandbox/dts/sandbox.dts.
  66. Command-line Options
  67. --------------------
  68. Various options are available, mostly for test purposes. Use -h to see
  69. available options. Some of these are described below:
  70. -t, --terminal <arg>
  71. The terminal is normally in what is called 'raw-with-sigs' mode. This means
  72. that you can use arrow keys for command editing and history, but if you
  73. press Ctrl-C, U-Boot will exit instead of handling this as a keypress.
  74. Other options are 'raw' (so Ctrl-C is handled within U-Boot) and 'cooked'
  75. (where the terminal is in cooked mode and cursor keys will not work, Ctrl-C
  76. will exit).
  77. -l
  78. Show the LCD emulation window.
  79. -d <device_tree>
  80. A device tree binary file can be provided with -d. If you edit the source
  81. (it is stored at arch/sandbox/dts/sandbox.dts) you must rebuild U-Boot to
  82. recreate the binary file.
  83. -D
  84. To use the default device tree, use -D.
  85. -T
  86. To use the test device tree, use -T.
  87. -c [<cmd>;]<cmd>
  88. To execute commands directly, use the -c option. You can specify a single
  89. command, or multiple commands separated by a semicolon, as is normal in
  90. U-Boot. Be careful with quoting as the shell will normally process and
  91. swallow quotes. When -c is used, U-Boot exits after the command is complete,
  92. but you can force it to go to interactive mode instead with -i.
  93. -i
  94. Go to interactive mode after executing the commands specified by -c.
  95. Environment Variables
  96. ---------------------
  97. UBOOT_SB_TIME_OFFSET
  98. This environment variable stores the offset of the emulated real time clock
  99. to the host's real time clock in seconds. The offset defaults to zero.
  100. Memory Emulation
  101. ----------------
  102. Memory emulation is supported, with the size set by CONFIG_SYS_SDRAM_SIZE.
  103. The -m option can be used to read memory from a file on start-up and write
  104. it when shutting down. This allows preserving of memory contents across
  105. test runs. You can tell U-Boot to remove the memory file after it is read
  106. (on start-up) with the --rm_memory option.
  107. To access U-Boot's emulated memory within the code, use map_sysmem(). This
  108. function is used throughout U-Boot to ensure that emulated memory is used
  109. rather than the U-Boot application memory. This provides memory starting
  110. at 0 and extending to the size of the emulation.
  111. Storing State
  112. -------------
  113. With sandbox you can write drivers which emulate the operation of drivers on
  114. real devices. Some of these drivers may want to record state which is
  115. preserved across U-Boot runs. This is particularly useful for testing. For
  116. example, the contents of a SPI flash chip should not disappear just because
  117. U-Boot exits.
  118. State is stored in a device tree file in a simple format which is driver-
  119. specific. You then use the -s option to specify the state file. Use -r to
  120. make U-Boot read the state on start-up (otherwise it starts empty) and -w
  121. to write it on exit (otherwise the stored state is left unchanged and any
  122. changes U-Boot made will be lost). You can also use -n to tell U-Boot to
  123. ignore any problems with missing state. This is useful when first running
  124. since the state file will be empty.
  125. The device tree file has one node for each driver - the driver can store
  126. whatever properties it likes in there. See 'Writing Sandbox Drivers' below
  127. for more details on how to get drivers to read and write their state.
  128. Running and Booting
  129. -------------------
  130. Since there is no machine architecture, sandbox U-Boot cannot actually boot
  131. a kernel, but it does support the bootm command. Filesystems, memory
  132. commands, hashing, FIT images, verified boot and many other features are
  133. supported.
  134. When 'bootm' runs a kernel, sandbox will exit, as U-Boot does on a real
  135. machine. Of course in this case, no kernel is run.
  136. It is also possible to tell U-Boot that it has jumped from a temporary
  137. previous U-Boot binary, with the -j option. That binary is automatically
  138. removed by the U-Boot that gets the -j option. This allows you to write
  139. tests which emulate the action of chain-loading U-Boot, typically used in
  140. a situation where a second 'updatable' U-Boot is stored on your board. It
  141. is very risky to overwrite or upgrade the only U-Boot on a board, since a
  142. power or other failure will brick the board and require return to the
  143. manufacturer in the case of a consumer device.
  144. Supported Drivers
  145. -----------------
  146. U-Boot sandbox supports these emulations:
  147. - Block devices
  148. - Chrome OS EC
  149. - GPIO
  150. - Host filesystem (access files on the host from within U-Boot)
  151. - I2C
  152. - Keyboard (Chrome OS)
  153. - LCD
  154. - Network
  155. - Serial (for console only)
  156. - Sound (incomplete - see sandbox_sdl_sound_init() for details)
  157. - SPI
  158. - SPI flash
  159. - TPM (Trusted Platform Module)
  160. A wide range of commands are implemented. Filesystems which use a block
  161. device are supported.
  162. Also sandbox supports driver model (CONFIG_DM) and associated commands.
  163. Sandbox Variants
  164. ----------------
  165. There are unfortunately quite a few variants at present:
  166. sandbox:
  167. should be used for most tests
  168. sandbox64:
  169. special build that forces a 64-bit host
  170. sandbox_flattree:
  171. builds with dev_read\_...() functions defined as inline.
  172. We need this build so that we can test those inline functions, and we
  173. cannot build with both the inline functions and the non-inline functions
  174. since they are named the same.
  175. sandbox_spl:
  176. builds sandbox with SPL support, so you can run spl/u-boot-spl
  177. and it will start up and then load ./u-boot. It is also possible to
  178. run ./u-boot directly.
  179. Of these sandbox_spl can probably be removed since it is a superset of sandbox.
  180. Most of the config options should be identical between these variants.
  181. Linux RAW Networking Bridge
  182. ---------------------------
  183. The sandbox_eth_raw driver bridges traffic between the bottom of the network
  184. stack and the RAW sockets API in Linux. This allows much of the U-Boot network
  185. functionality to be tested in sandbox against real network traffic.
  186. For Ethernet network adapters, the bridge utilizes the RAW AF_PACKET API. This
  187. is needed to get access to the lowest level of the network stack in Linux. This
  188. means that all of the Ethernet frame is included. This allows the U-Boot network
  189. stack to be fully used. In other words, nothing about the Linux network stack is
  190. involved in forming the packets that end up on the wire. To receive the
  191. responses to packets sent from U-Boot the network interface has to be set to
  192. promiscuous mode so that the network card won't filter out packets not destined
  193. for its configured (on Linux) MAC address.
  194. The RAW sockets Ethernet API requires elevated privileges in Linux. You can
  195. either run as root, or you can add the capability needed like so::
  196. sudo /sbin/setcap "CAP_NET_RAW+ep" /path/to/u-boot
  197. The default device tree for sandbox includes an entry for eth0 on the sandbox
  198. host machine whose alias is "eth1". The following are a few examples of network
  199. operations being tested on the eth0 interface.
  200. .. code-block:: none
  201. sudo /path/to/u-boot -D
  202. DHCP
  203. ....
  204. setenv autoload no
  205. setenv ethrotate no
  206. setenv ethact eth1
  207. dhcp
  208. PING
  209. ....
  210. setenv autoload no
  211. setenv ethrotate no
  212. setenv ethact eth1
  213. dhcp
  214. ping $gatewayip
  215. TFTP
  216. ....
  217. setenv autoload no
  218. setenv ethrotate no
  219. setenv ethact eth1
  220. dhcp
  221. setenv serverip WWW.XXX.YYY.ZZZ
  222. tftpboot u-boot.bin
  223. The bridge also supports (to a lesser extent) the localhost interface, 'lo'.
  224. The 'lo' interface cannot use the RAW AF_PACKET API because the lo interface
  225. doesn't support Ethernet-level traffic. It is a higher-level interface that is
  226. expected only to be used at the AF_INET level of the API. As such, the most raw
  227. we can get on that interface is the RAW AF_INET API on UDP. This allows us to
  228. set the IP_HDRINCL option to include everything except the Ethernet header in
  229. the packets we send and receive.
  230. Because only UDP is supported, ICMP traffic will not work, so expect that ping
  231. commands will time out.
  232. The default device tree for sandbox includes an entry for lo on the sandbox
  233. host machine whose alias is "eth5". The following is an example of a network
  234. operation being tested on the lo interface.
  235. .. code-block:: none
  236. TFTP
  237. ....
  238. setenv ethrotate no
  239. setenv ethact eth5
  240. tftpboot u-boot.bin
  241. SPI Emulation
  242. -------------
  243. Sandbox supports SPI and SPI flash emulation.
  244. The device can be enabled via a device tree, for example::
  245. spi@0 {
  246. #address-cells = <1>;
  247. #size-cells = <0>;
  248. reg = <0 1>;
  249. compatible = "sandbox,spi";
  250. cs-gpios = <0>, <&gpio_a 0>;
  251. spi.bin@0 {
  252. reg = <0>;
  253. compatible = "spansion,m25p16", "jedec,spi-nor";
  254. spi-max-frequency = <40000000>;
  255. sandbox,filename = "spi.bin";
  256. };
  257. };
  258. The file must be created in advance::
  259. $ dd if=/dev/zero of=spi.bin bs=1M count=2
  260. $ u-boot -T
  261. Here, you can use "-T" or "-D" option to specify test.dtb or u-boot.dtb,
  262. respectively, or "-d <file>" for your own dtb.
  263. With this setup you can issue SPI flash commands as normal::
  264. =>sf probe
  265. SF: Detected M25P16 with page size 64 KiB, total 2 MiB
  266. =>sf read 0 0 10000
  267. SF: 65536 bytes @ 0x0 Read: OK
  268. Since this is a full SPI emulation (rather than just flash), you can
  269. also use low-level SPI commands::
  270. =>sspi 0:0 32 9f
  271. FF202015
  272. This is issuing a READ_ID command and getting back 20 (ST Micro) part
  273. 0x2015 (the M25P16).
  274. Block Device Emulation
  275. ----------------------
  276. U-Boot can use raw disk images for block device emulation. To e.g. list
  277. the contents of the root directory on the second partion of the image
  278. "disk.raw", you can use the following commands::
  279. =>host bind 0 ./disk.raw
  280. =>ls host 0:2
  281. The device can be marked removeable with 'host bind -r'.
  282. A disk image can be created using the following commands::
  283. $> truncate -s 1200M ./disk.raw
  284. $> echo -e "label: gpt\n,64M,U\n,,L" | /usr/sbin/sgdisk ./disk.raw
  285. $> lodev=`sudo losetup -P -f --show ./disk.raw`
  286. $> sudo mkfs.vfat -n EFI -v ${lodev}p1
  287. $> sudo mkfs.ext4 -L ROOT -v ${lodev}p2
  288. or utilize the device described in test/py/make_test_disk.py::
  289. #!/usr/bin/python
  290. import make_test_disk
  291. make_test_disk.makeDisk()
  292. Writing Sandbox Drivers
  293. -----------------------
  294. Generally you should put your driver in a file containing the word 'sandbox'
  295. and put it in the same directory as other drivers of its type. You can then
  296. implement the same hooks as the other drivers.
  297. To access U-Boot's emulated memory, use map_sysmem() as mentioned above.
  298. If your driver needs to store configuration or state (such as SPI flash
  299. contents or emulated chip registers), you can use the device tree as
  300. described above. Define handlers for this with the SANDBOX_STATE_IO macro.
  301. See arch/sandbox/include/asm/state.h for documentation. In short you provide
  302. a node name, compatible string and functions to read and write the state.
  303. Since writing the state can expand the device tree, you may need to use
  304. state_setprop() which does this automatically and avoids running out of
  305. space. See existing code for examples.
  306. Debugging the init sequence
  307. ---------------------------
  308. If you get a failure in the initcall sequence, like this::
  309. initcall sequence 0000560775957c80 failed at call 0000000000048134 (err=-96)
  310. Then you use can use grep to see which init call failed, e.g.::
  311. $ grep 0000000000048134 u-boot.map
  312. stdio_add_devices
  313. Of course another option is to run it with a debugger such as gdb::
  314. $ gdb u-boot
  315. ...
  316. (gdb) br initcall.h:41
  317. Breakpoint 1 at 0x4db9d: initcall.h:41. (2 locations)
  318. Note that two locations are reported, since this function is used in both
  319. board_init_f() and board_init_r().
  320. .. code-block:: none
  321. (gdb) r
  322. Starting program: /tmp/b/sandbox/u-boot
  323. [Thread debugging using libthread_db enabled]
  324. Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
  325. U-Boot 2018.09-00264-ge0c2ba9814-dirty (Sep 22 2018 - 12:21:46 -0600)
  326. DRAM: 128 MiB
  327. MMC:
  328. Breakpoint 1, initcall_run_list (init_sequence=0x5555559619e0 <init_sequence_f>)
  329. at /scratch/sglass/cosarm/src/third_party/u-boot/files/include/initcall.h:41
  330. 41 printf("initcall sequence %p failed at call %p (err=%d)\n",
  331. (gdb) print *init_fnc_ptr
  332. $1 = (const init_fnc_t) 0x55555559c114 <stdio_add_devices>
  333. (gdb)
  334. This approach can be used on normal boards as well as sandbox.
  335. SDL_CONFIG
  336. ----------
  337. If sdl-config is on a different path from the default, set the SDL_CONFIG
  338. environment variable to the correct pathname before building U-Boot.
  339. Using valgrind / memcheck
  340. -------------------------
  341. It is possible to run U-Boot under valgrind to check memory allocations::
  342. valgrind u-boot
  343. If you are running sandbox SPL or TPL, then valgrind will not by default
  344. notice when U-Boot jumps from TPL to SPL, or from SPL to U-Boot proper. To
  345. fix this, use::
  346. valgrind --trace-children=yes u-boot
  347. Testing
  348. -------
  349. U-Boot sandbox can be used to run various tests, mostly in the test/
  350. directory.
  351. See :doc:`../develop/tests_sandbox` for more information and
  352. :doc:`../develop/testing` for information about testing generally.
  353. Memory Map
  354. ----------
  355. Sandbox has its own emulated memory starting at 0. Here are some of the things
  356. that are mapped into that memory:
  357. ======= ======================== ===============================
  358. Addr Config Usage
  359. ======= ======================== ===============================
  360. 0 CONFIG_SYS_FDT_LOAD_ADDR Device tree
  361. c000 CONFIG_BLOBLIST_ADDR Blob list
  362. 10000 CONFIG_MALLOC_F_ADDR Early memory allocation
  363. f0000 CONFIG_PRE_CON_BUF_ADDR Pre-console buffer
  364. 100000 CONFIG_TRACE_EARLY_ADDR Early trace buffer (if enabled). Also used
  365. as the SPL load buffer in spl_test_load().
  366. 200000 CONFIG_SYS_TEXT_BASE Load buffer for U-Boot (sandbox_spl only)
  367. ======= ======================== ===============================