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. CONFIG_SANDBOX is defined when building a native board.
  16. The board name is 'sandbox' but the vendor name is unset, so there is a
  17. single board in board/sandbox.
  18. CONFIG_SANDBOX_BIG_ENDIAN should be defined when running on big-endian
  19. machines.
  20. There are two versions of the sandbox: One using 32-bit-wide integers, and one
  21. using 64-bit-wide integers. The 32-bit version can be build and run on either
  22. 32 or 64-bit hosts by either selecting or deselecting CONFIG_SANDBOX_32BIT; by
  23. default, the sandbox it built for a 32-bit host. The sandbox using 64-bit-wide
  24. integers can only be built on 64-bit hosts.
  25. Note that standalone/API support is not available at present.
  26. Prerequisites
  27. -------------
  28. Here are some packages that are worth installing if you are doing sandbox or
  29. tools development in U-Boot:
  30. python3-pytest lzma lzma-alone lz4 python3 python3-virtualenv
  31. libssl1.0-dev
  32. Basic Operation
  33. ---------------
  34. To run sandbox U-Boot use something like::
  35. make sandbox_defconfig all
  36. ./u-boot
  37. Note: If you get errors about 'sdl-config: Command not found' you may need to
  38. install libsdl2.0-dev or similar to get SDL support. Alternatively you can
  39. build sandbox without SDL (i.e. no display/keyboard support) by removing
  40. the CONFIG_SANDBOX_SDL line in include/configs/sandbox.h or using::
  41. make sandbox_defconfig all NO_SDL=1
  42. ./u-boot
  43. U-Boot will start on your computer, showing a sandbox emulation of the serial
  44. console::
  45. U-Boot 2014.04 (Mar 20 2014 - 19:06:00)
  46. DRAM: 128 MiB
  47. Using default environment
  48. In: serial
  49. Out: lcd
  50. Err: lcd
  51. =>
  52. You can issue commands as your would normally. If the command you want is
  53. not supported you can add it to include/configs/sandbox.h.
  54. To exit, type 'reset' or press Ctrl-C.
  55. Console / LCD support
  56. ---------------------
  57. Assuming that CONFIG_SANDBOX_SDL is defined when building, you can run the
  58. sandbox with LCD and keyboard emulation, using something like::
  59. ./u-boot -d u-boot.dtb -l
  60. This will start U-Boot with a window showing the contents of the LCD. If
  61. that window has the focus then you will be able to type commands as you
  62. would on the console. You can adjust the display settings in the device
  63. tree file - see arch/sandbox/dts/sandbox.dts.
  64. Command-line Options
  65. --------------------
  66. Various options are available, mostly for test purposes. Use -h to see
  67. available options. Some of these are described below:
  68. * -t, --terminal <arg>
  69. - The terminal is normally in what is called 'raw-with-sigs' mode. This means
  70. that you can use arrow keys for command editing and history, but if you
  71. press Ctrl-C, U-Boot will exit instead of handling this as a keypress.
  72. Other options are 'raw' (so Ctrl-C is handled within U-Boot) and 'cooked'
  73. (where the terminal is in cooked mode and cursor keys will not work, Ctrl-C
  74. will exit).
  75. * -l
  76. - Show the LCD emulation window.
  77. * -d <device_tree>
  78. - A device tree binary file can be provided with -d. If you edit the source
  79. (it is stored at arch/sandbox/dts/sandbox.dts) you must rebuild U-Boot to
  80. recreate the binary file.
  81. * -D
  82. - To use the default device tree, use -D.
  83. * -T
  84. - To use the test device tree, use -T.
  85. * -c [<cmd>;]<cmd>
  86. - To execute commands directly, use the -c option. You can specify a single
  87. command, or multiple commands separated by a semicolon, as is normal in
  88. U-Boot. Be careful with quoting as the shell will normally process and
  89. swallow quotes. When -c is used, U-Boot exits after the command is complete,
  90. but you can force it to go to interactive mode instead with -i.
  91. * -i
  92. - Go to interactive mode after executing the commands specified by -c.
  93. Memory Emulation
  94. ----------------
  95. Memory emulation is supported, with the size set by CONFIG_SYS_SDRAM_SIZE.
  96. The -m option can be used to read memory from a file on start-up and write
  97. it when shutting down. This allows preserving of memory contents across
  98. test runs. You can tell U-Boot to remove the memory file after it is read
  99. (on start-up) with the --rm_memory option.
  100. To access U-Boot's emulated memory within the code, use map_sysmem(). This
  101. function is used throughout U-Boot to ensure that emulated memory is used
  102. rather than the U-Boot application memory. This provides memory starting
  103. at 0 and extending to the size of the emulation.
  104. Storing State
  105. -------------
  106. With sandbox you can write drivers which emulate the operation of drivers on
  107. real devices. Some of these drivers may want to record state which is
  108. preserved across U-Boot runs. This is particularly useful for testing. For
  109. example, the contents of a SPI flash chip should not disappear just because
  110. U-Boot exits.
  111. State is stored in a device tree file in a simple format which is driver-
  112. specific. You then use the -s option to specify the state file. Use -r to
  113. make U-Boot read the state on start-up (otherwise it starts empty) and -w
  114. to write it on exit (otherwise the stored state is left unchanged and any
  115. changes U-Boot made will be lost). You can also use -n to tell U-Boot to
  116. ignore any problems with missing state. This is useful when first running
  117. since the state file will be empty.
  118. The device tree file has one node for each driver - the driver can store
  119. whatever properties it likes in there. See 'Writing Sandbox Drivers' below
  120. for more details on how to get drivers to read and write their state.
  121. Running and Booting
  122. -------------------
  123. Since there is no machine architecture, sandbox U-Boot cannot actually boot
  124. a kernel, but it does support the bootm command. Filesystems, memory
  125. commands, hashing, FIT images, verified boot and many other features are
  126. supported.
  127. When 'bootm' runs a kernel, sandbox will exit, as U-Boot does on a real
  128. machine. Of course in this case, no kernel is run.
  129. It is also possible to tell U-Boot that it has jumped from a temporary
  130. previous U-Boot binary, with the -j option. That binary is automatically
  131. removed by the U-Boot that gets the -j option. This allows you to write
  132. tests which emulate the action of chain-loading U-Boot, typically used in
  133. a situation where a second 'updatable' U-Boot is stored on your board. It
  134. is very risky to overwrite or upgrade the only U-Boot on a board, since a
  135. power or other failure will brick the board and require return to the
  136. manufacturer in the case of a consumer device.
  137. Supported Drivers
  138. -----------------
  139. U-Boot sandbox supports these emulations:
  140. - Block devices
  141. - Chrome OS EC
  142. - GPIO
  143. - Host filesystem (access files on the host from within U-Boot)
  144. - I2C
  145. - Keyboard (Chrome OS)
  146. - LCD
  147. - Network
  148. - Serial (for console only)
  149. - Sound (incomplete - see sandbox_sdl_sound_init() for details)
  150. - SPI
  151. - SPI flash
  152. - TPM (Trusted Platform Module)
  153. A wide range of commands are implemented. Filesystems which use a block
  154. device are supported.
  155. Also sandbox supports driver model (CONFIG_DM) and associated commands.
  156. Sandbox Variants
  157. ----------------
  158. There are unfortunately quite a few variants at present:
  159. sandbox:
  160. should be used for most tests
  161. sandbox64:
  162. special build that forces a 64-bit host
  163. sandbox_flattree:
  164. builds with dev_read\_...() functions defined as inline.
  165. We need this build so that we can test those inline functions, and we
  166. cannot build with both the inline functions and the non-inline functions
  167. since they are named the same.
  168. sandbox_spl:
  169. builds sandbox with SPL support, so you can run spl/u-boot-spl
  170. and it will start up and then load ./u-boot. It is also possible to
  171. run ./u-boot directly.
  172. Of these sandbox_spl can probably be removed since it is a superset of sandbox.
  173. Most of the config options should be identical between these variants.
  174. Linux RAW Networking Bridge
  175. ---------------------------
  176. The sandbox_eth_raw driver bridges traffic between the bottom of the network
  177. stack and the RAW sockets API in Linux. This allows much of the U-Boot network
  178. functionality to be tested in sandbox against real network traffic.
  179. For Ethernet network adapters, the bridge utilizes the RAW AF_PACKET API. This
  180. is needed to get access to the lowest level of the network stack in Linux. This
  181. means that all of the Ethernet frame is included. This allows the U-Boot network
  182. stack to be fully used. In other words, nothing about the Linux network stack is
  183. involved in forming the packets that end up on the wire. To receive the
  184. responses to packets sent from U-Boot the network interface has to be set to
  185. promiscuous mode so that the network card won't filter out packets not destined
  186. for its configured (on Linux) MAC address.
  187. The RAW sockets Ethernet API requires elevated privileges in Linux. You can
  188. either run as root, or you can add the capability needed like so::
  189. sudo /sbin/setcap "CAP_NET_RAW+ep" /path/to/u-boot
  190. The default device tree for sandbox includes an entry for eth0 on the sandbox
  191. host machine whose alias is "eth1". The following are a few examples of network
  192. operations being tested on the eth0 interface.
  193. .. code-block:: none
  194. sudo /path/to/u-boot -D
  195. DHCP
  196. ....
  197. setenv autoload no
  198. setenv ethrotate no
  199. setenv ethact eth1
  200. dhcp
  201. PING
  202. ....
  203. setenv autoload no
  204. setenv ethrotate no
  205. setenv ethact eth1
  206. dhcp
  207. ping $gatewayip
  208. TFTP
  209. ....
  210. setenv autoload no
  211. setenv ethrotate no
  212. setenv ethact eth1
  213. dhcp
  214. setenv serverip WWW.XXX.YYY.ZZZ
  215. tftpboot u-boot.bin
  216. The bridge also supports (to a lesser extent) the localhost interface, 'lo'.
  217. The 'lo' interface cannot use the RAW AF_PACKET API because the lo interface
  218. doesn't support Ethernet-level traffic. It is a higher-level interface that is
  219. expected only to be used at the AF_INET level of the API. As such, the most raw
  220. we can get on that interface is the RAW AF_INET API on UDP. This allows us to
  221. set the IP_HDRINCL option to include everything except the Ethernet header in
  222. the packets we send and receive.
  223. Because only UDP is supported, ICMP traffic will not work, so expect that ping
  224. commands will time out.
  225. The default device tree for sandbox includes an entry for lo on the sandbox
  226. host machine whose alias is "eth5". The following is an example of a network
  227. operation being tested on the lo interface.
  228. .. code-block:: none
  229. TFTP
  230. ....
  231. setenv ethrotate no
  232. setenv ethact eth5
  233. tftpboot u-boot.bin
  234. SPI Emulation
  235. -------------
  236. Sandbox supports SPI and SPI flash emulation.
  237. The device can be enabled via a device tree, for example::
  238. spi@0 {
  239. #address-cells = <1>;
  240. #size-cells = <0>;
  241. reg = <0 1>;
  242. compatible = "sandbox,spi";
  243. cs-gpios = <0>, <&gpio_a 0>;
  244. spi.bin@0 {
  245. reg = <0>;
  246. compatible = "spansion,m25p16", "jedec,spi-nor";
  247. spi-max-frequency = <40000000>;
  248. sandbox,filename = "spi.bin";
  249. };
  250. };
  251. The file must be created in advance::
  252. $ dd if=/dev/zero of=spi.bin bs=1M count=2
  253. $ u-boot -T
  254. Here, you can use "-T" or "-D" option to specify test.dtb or u-boot.dtb,
  255. respectively, or "-d <file>" for your own dtb.
  256. With this setup you can issue SPI flash commands as normal::
  257. =>sf probe
  258. SF: Detected M25P16 with page size 64 KiB, total 2 MiB
  259. =>sf read 0 0 10000
  260. SF: 65536 bytes @ 0x0 Read: OK
  261. Since this is a full SPI emulation (rather than just flash), you can
  262. also use low-level SPI commands::
  263. =>sspi 0:0 32 9f
  264. FF202015
  265. This is issuing a READ_ID command and getting back 20 (ST Micro) part
  266. 0x2015 (the M25P16).
  267. Block Device Emulation
  268. ----------------------
  269. U-Boot can use raw disk images for block device emulation. To e.g. list
  270. the contents of the root directory on the second partion of the image
  271. "disk.raw", you can use the following commands::
  272. =>host bind 0 ./disk.raw
  273. =>ls host 0:2
  274. A disk image can be created using the following commands::
  275. $> truncate -s 1200M ./disk.raw
  276. $> echo -e "label: gpt\n,64M,U\n,,L" | /usr/sbin/sgdisk ./disk.raw
  277. $> lodev=`sudo losetup -P -f --show ./disk.raw`
  278. $> sudo mkfs.vfat -n EFI -v ${lodev}p1
  279. $> sudo mkfs.ext4 -L ROOT -v ${lodev}p2
  280. or utilize the device described in test/py/make_test_disk.py::
  281. #!/usr/bin/python
  282. import make_test_disk
  283. make_test_disk.makeDisk()
  284. Writing Sandbox Drivers
  285. -----------------------
  286. Generally you should put your driver in a file containing the word 'sandbox'
  287. and put it in the same directory as other drivers of its type. You can then
  288. implement the same hooks as the other drivers.
  289. To access U-Boot's emulated memory, use map_sysmem() as mentioned above.
  290. If your driver needs to store configuration or state (such as SPI flash
  291. contents or emulated chip registers), you can use the device tree as
  292. described above. Define handlers for this with the SANDBOX_STATE_IO macro.
  293. See arch/sandbox/include/asm/state.h for documentation. In short you provide
  294. a node name, compatible string and functions to read and write the state.
  295. Since writing the state can expand the device tree, you may need to use
  296. state_setprop() which does this automatically and avoids running out of
  297. space. See existing code for examples.
  298. Debugging the init sequence
  299. ---------------------------
  300. If you get a failure in the initcall sequence, like this::
  301. initcall sequence 0000560775957c80 failed at call 0000000000048134 (err=-96)
  302. Then you use can use grep to see which init call failed, e.g.::
  303. $ grep 0000000000048134 u-boot.map
  304. stdio_add_devices
  305. Of course another option is to run it with a debugger such as gdb::
  306. $ gdb u-boot
  307. ...
  308. (gdb) br initcall.h:41
  309. Breakpoint 1 at 0x4db9d: initcall.h:41. (2 locations)
  310. Note that two locations are reported, since this function is used in both
  311. board_init_f() and board_init_r().
  312. .. code-block:: none
  313. (gdb) r
  314. Starting program: /tmp/b/sandbox/u-boot
  315. [Thread debugging using libthread_db enabled]
  316. Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
  317. U-Boot 2018.09-00264-ge0c2ba9814-dirty (Sep 22 2018 - 12:21:46 -0600)
  318. DRAM: 128 MiB
  319. MMC:
  320. Breakpoint 1, initcall_run_list (init_sequence=0x5555559619e0 <init_sequence_f>)
  321. at /scratch/sglass/cosarm/src/third_party/u-boot/files/include/initcall.h:41
  322. 41 printf("initcall sequence %p failed at call %p (err=%d)\n",
  323. (gdb) print *init_fnc_ptr
  324. $1 = (const init_fnc_t) 0x55555559c114 <stdio_add_devices>
  325. (gdb)
  326. This approach can be used on normal boards as well as sandbox.
  327. SDL_CONFIG
  328. ----------
  329. If sdl-config is on a different path from the default, set the SDL_CONFIG
  330. environment variable to the correct pathname before building U-Boot.
  331. Using valgrind / memcheck
  332. -------------------------
  333. It is possible to run U-Boot under valgrind to check memory allocations::
  334. valgrind u-boot
  335. If you are running sandbox SPL or TPL, then valgrind will not by default
  336. notice when U-Boot jumps from TPL to SPL, or from SPL to U-Boot proper. To
  337. fix this, use::
  338. valgrind --trace-children=yes u-boot
  339. Testing
  340. -------
  341. U-Boot sandbox can be used to run various tests, mostly in the test/
  342. directory. These include:
  343. command_ut:
  344. Unit tests for command parsing and handling
  345. compression:
  346. Unit tests for U-Boot's compression algorithms, useful for
  347. security checking. It supports gzip, bzip2, lzma and lzo.
  348. driver model:
  349. Run this pytest::
  350. ./test/py/test.py --bd sandbox --build -k ut_dm -v
  351. image:
  352. Unit tests for images:
  353. test/image/test-imagetools.sh - multi-file images
  354. test/image/test-fit.py - FIT images
  355. tracing:
  356. test/trace/test-trace.sh tests the tracing system (see README.trace)
  357. verified boot:
  358. See test/vboot/vboot_test.sh for this
  359. If you change or enhance any of the above subsystems, you shold write or
  360. expand a test and include it with your patch series submission. Test
  361. coverage in U-Boot is limited, as we need to work to improve it.
  362. Note that many of these tests are implemented as commands which you can
  363. run natively on your board if desired (and enabled).
  364. To run all tests use "make check".
  365. To run a single test in an existing sandbox build, you can use -T to use the
  366. test device tree, and -c to select the test:
  367. /tmp/b/sandbox/u-boot -T -c "ut dm pci_busdev"
  368. This runs dm_test_pci_busdev() which is in test/dm/pci.c
  369. Memory Map
  370. ----------
  371. Sandbox has its own emulated memory starting at 0. Here are some of the things
  372. that are mapped into that memory:
  373. ======= ======================== ===============================
  374. Addr Config Usage
  375. ======= ======================== ===============================
  376. 0 CONFIG_SYS_FDT_LOAD_ADDR Device tree
  377. e000 CONFIG_BLOBLIST_ADDR Blob list
  378. 10000 CONFIG_MALLOC_F_ADDR Early memory allocation
  379. f0000 CONFIG_PRE_CON_BUF_ADDR Pre-console buffer
  380. 100000 CONFIG_TRACE_EARLY_ADDR Early trace buffer (if enabled)
  381. ======= ======================== ===============================