1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * Copyright (c) 2014 The Chromium OS Authors.
6 Native Execution of U-Boot
7 ==========================
9 The 'sandbox' architecture is designed to allow U-Boot to run under Linux on
10 almost any hardware. To achieve this it builds U-Boot (so far as possible)
11 as a normal C application with a main() and normal C libraries.
13 All of U-Boot's architecture-specific code therefore cannot be built as part
14 of the sandbox U-Boot. The purpose of running U-Boot under Linux is to test
15 all the generic code, not specific to any one architecture. The idea is to
16 create unit tests which we can run to test this upper level code.
18 CONFIG_SANDBOX is defined when building a native board.
20 The board name is 'sandbox' but the vendor name is unset, so there is a
21 single board in board/sandbox.
23 CONFIG_SANDBOX_BIG_ENDIAN should be defined when running on big-endian
26 There are two versions of the sandbox: One using 32-bit-wide integers, and one
27 using 64-bit-wide integers. The 32-bit version can be build and run on either
28 32 or 64-bit hosts by either selecting or deselecting CONFIG_SANDBOX_32BIT; by
29 default, the sandbox it built for a 32-bit host. The sandbox using 64-bit-wide
30 integers can only be built on 64-bit hosts.
32 Note that standalone/API support is not available at present.
38 To run sandbox U-Boot use something like:
40 make sandbox_defconfig all
44 If you get errors about 'sdl-config: Command not found' you may need to
45 install libsdl1.2-dev or similar to get SDL support. Alternatively you can
46 build sandbox without SDL (i.e. no display/keyboard support) by removing
47 the CONFIG_SANDBOX_SDL line in include/configs/sandbox.h or using:
49 make sandbox_defconfig all NO_SDL=1
52 U-Boot will start on your computer, showing a sandbox emulation of the serial
56 U-Boot 2014.04 (Mar 20 2014 - 19:06:00)
59 Using default environment
66 You can issue commands as your would normally. If the command you want is
67 not supported you can add it to include/configs/sandbox.h.
69 To exit, type 'reset' or press Ctrl-C.
75 Assuming that CONFIG_SANDBOX_SDL is defined when building, you can run the
76 sandbox with LCD and keyboard emulation, using something like:
78 ./u-boot -d u-boot.dtb -l
80 This will start U-Boot with a window showing the contents of the LCD. If
81 that window has the focus then you will be able to type commands as you
82 would on the console. You can adjust the display settings in the device
83 tree file - see arch/sandbox/dts/sandbox.dts.
89 Various options are available, mostly for test purposes. Use -h to see
90 available options. Some of these are described below.
92 The terminal is normally in what is called 'raw-with-sigs' mode. This means
93 that you can use arrow keys for command editing and history, but if you
94 press Ctrl-C, U-Boot will exit instead of handling this as a keypress.
96 Other options are 'raw' (so Ctrl-C is handled within U-Boot) and 'cooked'
97 (where the terminal is in cooked mode and cursor keys will not work, Ctrl-C
100 As mentioned above, -l causes the LCD emulation window to be shown.
102 A device tree binary file can be provided with -d. If you edit the source
103 (it is stored at arch/sandbox/dts/sandbox.dts) you must rebuild U-Boot to
104 recreate the binary file.
106 To execute commands directly, use the -c option. You can specify a single
107 command, or multiple commands separated by a semicolon, as is normal in
108 U-Boot. Be careful with quoting as the shell will normally process and
109 swallow quotes. When -c is used, U-Boot exits after the command is complete,
110 but you can force it to go to interactive mode instead with -i.
116 Memory emulation is supported, with the size set by CONFIG_SYS_SDRAM_SIZE.
117 The -m option can be used to read memory from a file on start-up and write
118 it when shutting down. This allows preserving of memory contents across
119 test runs. You can tell U-Boot to remove the memory file after it is read
120 (on start-up) with the --rm_memory option.
122 To access U-Boot's emulated memory within the code, use map_sysmem(). This
123 function is used throughout U-Boot to ensure that emulated memory is used
124 rather than the U-Boot application memory. This provides memory starting
125 at 0 and extending to the size of the emulation.
131 With sandbox you can write drivers which emulate the operation of drivers on
132 real devices. Some of these drivers may want to record state which is
133 preserved across U-Boot runs. This is particularly useful for testing. For
134 example, the contents of a SPI flash chip should not disappear just because
137 State is stored in a device tree file in a simple format which is driver-
138 specific. You then use the -s option to specify the state file. Use -r to
139 make U-Boot read the state on start-up (otherwise it starts empty) and -w
140 to write it on exit (otherwise the stored state is left unchanged and any
141 changes U-Boot made will be lost). You can also use -n to tell U-Boot to
142 ignore any problems with missing state. This is useful when first running
143 since the state file will be empty.
145 The device tree file has one node for each driver - the driver can store
146 whatever properties it likes in there. See 'Writing Sandbox Drivers' below
147 for more details on how to get drivers to read and write their state.
153 Since there is no machine architecture, sandbox U-Boot cannot actually boot
154 a kernel, but it does support the bootm command. Filesystems, memory
155 commands, hashing, FIT images, verified boot and many other features are
158 When 'bootm' runs a kernel, sandbox will exit, as U-Boot does on a real
159 machine. Of course in this case, no kernel is run.
161 It is also possible to tell U-Boot that it has jumped from a temporary
162 previous U-Boot binary, with the -j option. That binary is automatically
163 removed by the U-Boot that gets the -j option. This allows you to write
164 tests which emulate the action of chain-loading U-Boot, typically used in
165 a situation where a second 'updatable' U-Boot is stored on your board. It
166 is very risky to overwrite or upgrade the only U-Boot on a board, since a
167 power or other failure will brick the board and require return to the
168 manufacturer in the case of a consumer device.
174 U-Boot sandbox supports these emulations:
179 - Host filesystem (access files on the host from within U-Boot)
181 - Keyboard (Chrome OS)
184 - Serial (for console only)
185 - Sound (incomplete - see sandbox_sdl_sound_init() for details)
188 - TPM (Trusted Platform Module)
190 A wide range of commands are implemented. Filesystems which use a block
191 device are supported.
193 Also sandbox supports driver model (CONFIG_DM) and associated commands.
199 There are unfortunately quite a few variants at present:
201 sandbox - should be used for most tests
202 sandbox64 - special build that forces a 64-bit host
203 sandbox_flattree - builds with dev_read_...() functions defined as inline.
204 We need this build so that we can test those inline functions, and we
205 cannot build with both the inline functions and the non-inline functions
206 since they are named the same.
207 sandbox_noblk - builds without CONFIG_BLK, which means the legacy block
208 drivers are used. We cannot use both the legacy and driver-model block
209 drivers since they implement the same functions
210 sandbox_spl - builds sandbox with SPL support, so you can run spl/u-boot-spl
211 and it will start up and then load ./u-boot. It is also possible to
212 run ./u-boot directly.
214 Of these sandbox_noblk can be removed once CONFIG_BLK is used everwhere, and
215 sandbox_spl can probably be removed since it is a superset of sandbox.
217 Most of the config options should be identical between these variants.
220 Linux RAW Networking Bridge
221 ---------------------------
223 The sandbox_eth_raw driver bridges traffic between the bottom of the network
224 stack and the RAW sockets API in Linux. This allows much of the U-Boot network
225 functionality to be tested in sandbox against real network traffic.
227 For Ethernet network adapters, the bridge utilizes the RAW AF_PACKET API. This
228 is needed to get access to the lowest level of the network stack in Linux. This
229 means that all of the Ethernet frame is included. This allows the U-Boot network
230 stack to be fully used. In other words, nothing about the Linux network stack is
231 involved in forming the packets that end up on the wire. To receive the
232 responses to packets sent from U-Boot the network interface has to be set to
233 promiscuous mode so that the network card won't filter out packets not destined
234 for its configured (on Linux) MAC address.
236 The RAW sockets Ethernet API requires elevated privileges in Linux. You can
237 either run as root, or you can add the capability needed like so:
239 sudo /sbin/setcap "CAP_NET_RAW+ep" /path/to/u-boot
241 The default device tree for sandbox includes an entry for eth0 on the sandbox
242 host machine whose alias is "eth1". The following are a few examples of network
243 operations being tested on the eth0 interface.
245 sudo /path/to/u-boot -D
271 setenv serverip WWW.XXX.YYY.ZZZ
274 The bridge also supports (to a lesser extent) the localhost interface, 'lo'.
276 The 'lo' interface cannot use the RAW AF_PACKET API because the lo interface
277 doesn't support Ethernet-level traffic. It is a higher-level interface that is
278 expected only to be used at the AF_INET level of the API. As such, the most raw
279 we can get on that interface is the RAW AF_INET API on UDP. This allows us to
280 set the IP_HDRINCL option to include everything except the Ethernet header in
281 the packets we send and receive.
283 Because only UDP is supported, ICMP traffic will not work, so expect that ping
284 commands will time out.
286 The default device tree for sandbox includes an entry for lo on the sandbox
287 host machine whose alias is "eth5". The following is an example of a network
288 operation being tested on the lo interface.
301 Sandbox supports SPI and SPI flash emulation.
303 This is controlled by the spi_sf argument, the format of which is:
308 cs - SPI chip select number
309 device - SPI device emulation name
310 file - File on disk containing the data
314 dd if=/dev/zero of=spi.bin bs=1M count=4
315 ./u-boot --spi_sf 0:0:M25P16:spi.bin
317 With this setup you can issue SPI flash commands as normal:
320 SF: Detected M25P16 with page size 64 KiB, total 2 MiB
322 SF: 65536 bytes @ 0x0 Read: OK
325 Since this is a full SPI emulation (rather than just flash), you can
326 also use low-level SPI commands:
331 This is issuing a READ_ID command and getting back 20 (ST Micro) part
334 Drivers are connected to a particular bus/cs using sandbox's state
335 structure (see the 'spi' member). A set of operations must be provided
339 Configuration settings for the curious are:
341 CONFIG_SANDBOX_SPI_MAX_BUS
342 The maximum number of SPI buses supported by the driver (default 1).
344 CONFIG_SANDBOX_SPI_MAX_CS
345 The maximum number of chip selects supported by the driver
349 The idle value on the SPI bus
352 Block Device Emulation
353 ----------------------
355 U-Boot can use raw disk images for block device emulation. To e.g. list
356 the contents of the root directory on the second partion of the image
357 "disk.raw", you can use the following commands:
359 =>host bind 0 ./disk.raw
362 A disk image can be created using the following commands:
364 $> truncate -s 1200M ./disk.raw
365 $> echo -e "label: gpt\n,64M,U\n,,L" | /usr/sbin/sgdisk ./disk.raw
366 $> lodev=`sudo losetup -P -f --show ./disk.raw`
367 $> sudo mkfs.vfat -n EFI -v ${lodev}p1
368 $> sudo mkfs.ext4 -L ROOT -v ${lodev}p2
370 or utilize the device described in test/py/make_test_disk.py:
373 import make_test_disk
374 make_test_disk.makeDisk()
376 Writing Sandbox Drivers
377 -----------------------
379 Generally you should put your driver in a file containing the word 'sandbox'
380 and put it in the same directory as other drivers of its type. You can then
381 implement the same hooks as the other drivers.
383 To access U-Boot's emulated memory, use map_sysmem() as mentioned above.
385 If your driver needs to store configuration or state (such as SPI flash
386 contents or emulated chip registers), you can use the device tree as
387 described above. Define handlers for this with the SANDBOX_STATE_IO macro.
388 See arch/sandbox/include/asm/state.h for documentation. In short you provide
389 a node name, compatible string and functions to read and write the state.
390 Since writing the state can expand the device tree, you may need to use
391 state_setprop() which does this automatically and avoids running out of
392 space. See existing code for examples.
395 Debugging the init sequence
396 ---------------------------
398 If you get a failure in the initcall sequence, like this:
400 initcall sequence 0000560775957c80 failed at call 0000000000048134 (err=-96)
402 Then you use can use grep to see which init call failed, e.g.:
404 $ grep 0000000000048134 u-boot.map
407 Of course another option is to run it with a debugger such as gdb:
411 (gdb) br initcall.h:41
412 Breakpoint 1 at 0x4db9d: initcall.h:41. (2 locations)
414 Note that two locations are reported, since this function is used in both
415 board_init_f() and board_init_r().
418 Starting program: /tmp/b/sandbox/u-boot
419 [Thread debugging using libthread_db enabled]
420 Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
422 U-Boot 2018.09-00264-ge0c2ba9814-dirty (Sep 22 2018 - 12:21:46 -0600)
427 Breakpoint 1, initcall_run_list (init_sequence=0x5555559619e0 <init_sequence_f>)
428 at /scratch/sglass/cosarm/src/third_party/u-boot/files/include/initcall.h:41
429 41 printf("initcall sequence %p failed at call %p (err=%d)\n",
430 (gdb) print *init_fnc_ptr
431 $1 = (const init_fnc_t) 0x55555559c114 <stdio_add_devices>
435 This approach can be used on normal boards as well as sandbox.
441 U-Boot sandbox can be used to run various tests, mostly in the test/
442 directory. These include:
445 - Unit tests for command parsing and handling
447 - Unit tests for U-Boot's compression algorithms, useful for
448 security checking. It supports gzip, bzip2, lzma and lzo.
451 ./test/py/test.py --bd sandbox --build -k ut_dm -v
453 - Unit tests for images:
454 test/image/test-imagetools.sh - multi-file images
455 test/image/test-fit.py - FIT images
457 - test/trace/test-trace.sh tests the tracing system (see README.trace)
459 - See test/vboot/vboot_test.sh for this
461 If you change or enhance any of the above subsystems, you shold write or
462 expand a test and include it with your patch series submission. Test
463 coverage in U-Boot is limited, as we need to work to improve it.
465 Note that many of these tests are implemented as commands which you can
466 run natively on your board if desired (and enabled).
468 To run all tests use "make check".
474 Sandbox has its own emulated memory starting at 0. Here are some of the things
475 that are mapped into that memory:
477 0 CONFIG_SYS_FDT_LOAD_ADDR Device tree
478 e000 CONFIG_BLOBLIST_ADDR Blob list
479 10000 CONFIG_MALLOC_F_ADDR Early memory allocation
483 Simon Glass <sjg@chromium.org>