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