1 .. SPDX-License-Identifier: GPL-2.0+ */
2 .. Copyright (c) 2014 The Chromium OS Authors.
3 .. sectionauthor:: Simon Glass <sjg@chromium.org>
8 Native Execution of U-Boot
9 --------------------------
11 The 'sandbox' architecture is designed to allow U-Boot to run under Linux on
12 almost any hardware. To achieve this it builds U-Boot (so far as possible)
13 as a normal C application with a main() and normal C libraries.
15 All of U-Boot's architecture-specific code therefore cannot be built as part
16 of the sandbox U-Boot. The purpose of running U-Boot under Linux is to test
17 all the generic code, not specific to any one architecture. The idea is to
18 create unit tests which we can run to test this upper level code.
20 CONFIG_SANDBOX is defined when building a native board.
22 The board name is 'sandbox' but the vendor name is unset, so there is a
23 single board in board/sandbox.
25 CONFIG_SANDBOX_BIG_ENDIAN should be defined when running on big-endian
28 There are two versions of the sandbox: One using 32-bit-wide integers, and one
29 using 64-bit-wide integers. The 32-bit version can be build and run on either
30 32 or 64-bit hosts by either selecting or deselecting CONFIG_SANDBOX_32BIT; by
31 default, the sandbox it built for a 32-bit host. The sandbox using 64-bit-wide
32 integers can only be built on 64-bit hosts.
34 Note that standalone/API support is not available at present.
40 To run sandbox U-Boot use something like::
42 make sandbox_defconfig all
45 Note: If you get errors about 'sdl-config: Command not found' you may need to
46 install libsdl1.2-dev or similar to get SDL support. Alternatively you can
47 build sandbox without SDL (i.e. no display/keyboard support) by removing
48 the CONFIG_SANDBOX_SDL line in include/configs/sandbox.h or using::
50 make sandbox_defconfig all NO_SDL=1
53 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 use the default device tree, use -D. To use the test device tree, use -T.
108 To execute commands directly, use the -c option. You can specify a single
109 command, or multiple commands separated by a semicolon, as is normal in
110 U-Boot. Be careful with quoting as the shell will normally process and
111 swallow quotes. When -c is used, U-Boot exits after the command is complete,
112 but you can force it to go to interactive mode instead with -i.
118 Memory emulation is supported, with the size set by CONFIG_SYS_SDRAM_SIZE.
119 The -m option can be used to read memory from a file on start-up and write
120 it when shutting down. This allows preserving of memory contents across
121 test runs. You can tell U-Boot to remove the memory file after it is read
122 (on start-up) with the --rm_memory option.
124 To access U-Boot's emulated memory within the code, use map_sysmem(). This
125 function is used throughout U-Boot to ensure that emulated memory is used
126 rather than the U-Boot application memory. This provides memory starting
127 at 0 and extending to the size of the emulation.
133 With sandbox you can write drivers which emulate the operation of drivers on
134 real devices. Some of these drivers may want to record state which is
135 preserved across U-Boot runs. This is particularly useful for testing. For
136 example, the contents of a SPI flash chip should not disappear just because
139 State is stored in a device tree file in a simple format which is driver-
140 specific. You then use the -s option to specify the state file. Use -r to
141 make U-Boot read the state on start-up (otherwise it starts empty) and -w
142 to write it on exit (otherwise the stored state is left unchanged and any
143 changes U-Boot made will be lost). You can also use -n to tell U-Boot to
144 ignore any problems with missing state. This is useful when first running
145 since the state file will be empty.
147 The device tree file has one node for each driver - the driver can store
148 whatever properties it likes in there. See 'Writing Sandbox Drivers' below
149 for more details on how to get drivers to read and write their state.
155 Since there is no machine architecture, sandbox U-Boot cannot actually boot
156 a kernel, but it does support the bootm command. Filesystems, memory
157 commands, hashing, FIT images, verified boot and many other features are
160 When 'bootm' runs a kernel, sandbox will exit, as U-Boot does on a real
161 machine. Of course in this case, no kernel is run.
163 It is also possible to tell U-Boot that it has jumped from a temporary
164 previous U-Boot binary, with the -j option. That binary is automatically
165 removed by the U-Boot that gets the -j option. This allows you to write
166 tests which emulate the action of chain-loading U-Boot, typically used in
167 a situation where a second 'updatable' U-Boot is stored on your board. It
168 is very risky to overwrite or upgrade the only U-Boot on a board, since a
169 power or other failure will brick the board and require return to the
170 manufacturer in the case of a consumer device.
176 U-Boot sandbox supports these emulations:
181 - Host filesystem (access files on the host from within U-Boot)
183 - Keyboard (Chrome OS)
186 - Serial (for console only)
187 - Sound (incomplete - see sandbox_sdl_sound_init() for details)
190 - TPM (Trusted Platform Module)
192 A wide range of commands are implemented. Filesystems which use a block
193 device are supported.
195 Also sandbox supports driver model (CONFIG_DM) and associated commands.
201 There are unfortunately quite a few variants at present:
204 should be used for most tests
206 special build that forces a 64-bit host
208 builds with dev_read\_...() functions defined as inline.
209 We need this build so that we can test those inline functions, and we
210 cannot build with both the inline functions and the non-inline functions
211 since they are named the same.
213 builds sandbox with SPL support, so you can run spl/u-boot-spl
214 and it will start up and then load ./u-boot. It is also possible to
215 run ./u-boot directly.
217 Of these sandbox_spl can probably be removed since it is a superset of sandbox.
219 Most of the config options should be identical between these variants.
222 Linux RAW Networking Bridge
223 ---------------------------
225 The sandbox_eth_raw driver bridges traffic between the bottom of the network
226 stack and the RAW sockets API in Linux. This allows much of the U-Boot network
227 functionality to be tested in sandbox against real network traffic.
229 For Ethernet network adapters, the bridge utilizes the RAW AF_PACKET API. This
230 is needed to get access to the lowest level of the network stack in Linux. This
231 means that all of the Ethernet frame is included. This allows the U-Boot network
232 stack to be fully used. In other words, nothing about the Linux network stack is
233 involved in forming the packets that end up on the wire. To receive the
234 responses to packets sent from U-Boot the network interface has to be set to
235 promiscuous mode so that the network card won't filter out packets not destined
236 for its configured (on Linux) MAC address.
238 The RAW sockets Ethernet API requires elevated privileges in Linux. You can
239 either run as root, or you can add the capability needed like so::
241 sudo /sbin/setcap "CAP_NET_RAW+ep" /path/to/u-boot
243 The default device tree for sandbox includes an entry for eth0 on the sandbox
244 host machine whose alias is "eth1". The following are a few examples of network
245 operations being tested on the eth0 interface.
249 sudo /path/to/u-boot -D
275 setenv serverip WWW.XXX.YYY.ZZZ
278 The bridge also supports (to a lesser extent) the localhost interface, 'lo'.
280 The 'lo' interface cannot use the RAW AF_PACKET API because the lo interface
281 doesn't support Ethernet-level traffic. It is a higher-level interface that is
282 expected only to be used at the AF_INET level of the API. As such, the most raw
283 we can get on that interface is the RAW AF_INET API on UDP. This allows us to
284 set the IP_HDRINCL option to include everything except the Ethernet header in
285 the packets we send and receive.
287 Because only UDP is supported, ICMP traffic will not work, so expect that ping
288 commands will time out.
290 The default device tree for sandbox includes an entry for lo on the sandbox
291 host machine whose alias is "eth5". The following is an example of a network
292 operation being tested on the lo interface.
307 Sandbox supports SPI and SPI flash emulation.
309 This is controlled by the spi_sf argument, the format of which is::
314 cs - SPI chip select number
315 device - SPI device emulation name
316 file - File on disk containing the data
320 dd if=/dev/zero of=spi.bin bs=1M count=4
321 ./u-boot --spi_sf 0:0:M25P16:spi.bin
323 With this setup you can issue SPI flash commands as normal::
326 SF: Detected M25P16 with page size 64 KiB, total 2 MiB
328 SF: 65536 bytes @ 0x0 Read: OK
330 Since this is a full SPI emulation (rather than just flash), you can
331 also use low-level SPI commands::
336 This is issuing a READ_ID command and getting back 20 (ST Micro) part
339 Drivers are connected to a particular bus/cs using sandbox's state
340 structure (see the 'spi' member). A set of operations must be provided
344 Configuration settings for the curious are:
346 CONFIG_SANDBOX_SPI_MAX_BUS:
347 The maximum number of SPI buses supported by the driver (default 1).
349 CONFIG_SANDBOX_SPI_MAX_CS:
350 The maximum number of chip selects supported by the driver (default 10).
353 The idle value on the SPI bus
356 Block Device Emulation
357 ----------------------
359 U-Boot can use raw disk images for block device emulation. To e.g. list
360 the contents of the root directory on the second partion of the image
361 "disk.raw", you can use the following commands::
363 =>host bind 0 ./disk.raw
366 A disk image can be created using the following commands::
368 $> truncate -s 1200M ./disk.raw
369 $> echo -e "label: gpt\n,64M,U\n,,L" | /usr/sbin/sgdisk ./disk.raw
370 $> lodev=`sudo losetup -P -f --show ./disk.raw`
371 $> sudo mkfs.vfat -n EFI -v ${lodev}p1
372 $> sudo mkfs.ext4 -L ROOT -v ${lodev}p2
374 or utilize the device described in test/py/make_test_disk.py::
377 import make_test_disk
378 make_test_disk.makeDisk()
380 Writing Sandbox Drivers
381 -----------------------
383 Generally you should put your driver in a file containing the word 'sandbox'
384 and put it in the same directory as other drivers of its type. You can then
385 implement the same hooks as the other drivers.
387 To access U-Boot's emulated memory, use map_sysmem() as mentioned above.
389 If your driver needs to store configuration or state (such as SPI flash
390 contents or emulated chip registers), you can use the device tree as
391 described above. Define handlers for this with the SANDBOX_STATE_IO macro.
392 See arch/sandbox/include/asm/state.h for documentation. In short you provide
393 a node name, compatible string and functions to read and write the state.
394 Since writing the state can expand the device tree, you may need to use
395 state_setprop() which does this automatically and avoids running out of
396 space. See existing code for examples.
399 Debugging the init sequence
400 ---------------------------
402 If you get a failure in the initcall sequence, like this::
404 initcall sequence 0000560775957c80 failed at call 0000000000048134 (err=-96)
406 Then you use can use grep to see which init call failed, e.g.::
408 $ grep 0000000000048134 u-boot.map
411 Of course another option is to run it with a debugger such as gdb::
415 (gdb) br initcall.h:41
416 Breakpoint 1 at 0x4db9d: initcall.h:41. (2 locations)
418 Note that two locations are reported, since this function is used in both
419 board_init_f() and board_init_r().
424 Starting program: /tmp/b/sandbox/u-boot
425 [Thread debugging using libthread_db enabled]
426 Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
428 U-Boot 2018.09-00264-ge0c2ba9814-dirty (Sep 22 2018 - 12:21:46 -0600)
433 Breakpoint 1, initcall_run_list (init_sequence=0x5555559619e0 <init_sequence_f>)
434 at /scratch/sglass/cosarm/src/third_party/u-boot/files/include/initcall.h:41
435 41 printf("initcall sequence %p failed at call %p (err=%d)\n",
436 (gdb) print *init_fnc_ptr
437 $1 = (const init_fnc_t) 0x55555559c114 <stdio_add_devices>
441 This approach can be used on normal boards as well as sandbox.
447 If sdl-config is on a different path from the default, set the SDL_CONFIG
448 environment variable to the correct pathname before building U-Boot.
451 Using valgrind / memcheck
452 -------------------------
454 It is possible to run U-Boot under valgrind to check memory allocations::
458 If you are running sandbox SPL or TPL, then valgrind will not by default
459 notice when U-Boot jumps from TPL to SPL, or from SPL to U-Boot proper. To
462 valgrind --trace-children=yes u-boot
468 U-Boot sandbox can be used to run various tests, mostly in the test/
469 directory. These include:
472 Unit tests for command parsing and handling
474 Unit tests for U-Boot's compression algorithms, useful for
475 security checking. It supports gzip, bzip2, lzma and lzo.
479 ./test/py/test.py --bd sandbox --build -k ut_dm -v
482 Unit tests for images:
483 test/image/test-imagetools.sh - multi-file images
484 test/image/test-fit.py - FIT images
486 test/trace/test-trace.sh tests the tracing system (see README.trace)
488 See test/vboot/vboot_test.sh for this
490 If you change or enhance any of the above subsystems, you shold write or
491 expand a test and include it with your patch series submission. Test
492 coverage in U-Boot is limited, as we need to work to improve it.
494 Note that many of these tests are implemented as commands which you can
495 run natively on your board if desired (and enabled).
497 To run all tests use "make check".
499 To run a single test in an existing sandbox build, you can use -T to use the
500 test device tree, and -c to select the test:
502 /tmp/b/sandbox/u-boot -T -c "ut dm pci_busdev"
504 This runs dm_test_pci_busdev() which is in test/dm/pci.c
510 Sandbox has its own emulated memory starting at 0. Here are some of the things
511 that are mapped into that memory:
513 ======= ======================== ===============================
515 ======= ======================== ===============================
516 0 CONFIG_SYS_FDT_LOAD_ADDR Device tree
517 e000 CONFIG_BLOBLIST_ADDR Blob list
518 10000 CONFIG_MALLOC_F_ADDR Early memory allocation
519 f0000 CONFIG_PRE_CON_BUF_ADDR Pre-console buffer
520 100000 CONFIG_TRACE_EARLY_ADDR Early trace buffer (if enabled)
521 ======= ======================== ===============================