dm command

Synopis

dm compat
dm devres
dm drivers
dm static
dm tree [-s]
dm uclass

Description

The dm command allows viewing information about driver model, including the tree of devices and list of available uclasses.

dm compat

This shows the compatible strings associated with each driver. Often there is only one, but multiple strings are shown on their own line. These strings can be looked up in the device tree files for each board, to see which driver is used for each node.

dm devres

This shows a list of a devres (device resource) records for a device. Some drivers use the devres API to allocate memory, so that it can be freed automatically (without any code needed in the driver’s remove() method) when the device is removed.

This feature is controlled by CONFIG_DEVRES so no useful output is obtained if this option is disabled.

dm drivers

This shows all the available drivers, their uclass and a list of devices that use that driver, each on its own line. Drivers with no devices are shown with <none> as the driver name.

dm mem

This subcommand is really just for debugging and exploration. It can be enabled with the CONFIG_DM_STATS option.

All output is in hex except that in brackets which is decimal.

The output consists of a header shows the size of the main device model structures (struct udevice, struct driver, struct uclass and struct uc_driver) and the count and memory used by each (number of devices, memory used by devices, memory used by device names, number of uclasses, memory used by uclasses).

After that is a table of information about each type of data that can be attached to a device, showing the number that have non-null data for that type, the total size of all that data, the amount of memory used in total, the amount that would be used if this type uses tags instead and the amount that would be thus saved.

The driver_data line shows the number of devices which have non-NULL driver data.

The tags line shows the number of tags and the memory used by those.

At the bottom is an indication of the total memory usage obtained by undertaking various changes, none of which is currently implemented in U-Boot:

With tags

Using tags instead of all attached types

Singly linked

Using a singly linked list

driver index

Using a driver index instead of a pointer

uclass index

Using a uclass index instead of a pointer

Drop device name

Using empty device names

dm static

This shows devices bound by platform data, i.e. not from the device tree. There are normally none of these, but some boards may use static devices for space reasons.

dm tree

This shows the full tree of devices including the following fields:

uclass

Shows the name of the uclass for the device

Index

Shows the index number of the device, within the uclass. This shows the ordering within the uclass, but not the sequence number.

Probed

Shows + if the device is active

Driver

Shows the name of the driver that this device uses

Name

Shows the device name as well as the tree structure, since child devices are shown attached to their parent.

If -s is given, the top-level devices (those which are children of the root device) are shown sorted in order of uclass ID, so it is easier to find a particular device type.

dm uclass

This shows each uclass along with a list of devices in that uclass. The uclass ID is shown (e.g. uclass 7) and its name.

For each device, the format is:

n    name @ a, seq s

where n is the index within the uclass, a is the address of the device in memory and s is the sequence number of the device.

Examples

dm compat

This example shows an abridged version of the sandbox output:

=> dm compat
Driver                Compatible
--------------------------------
act8846_reg
sandbox_adder         sandbox,adder
axi_sandbox_bus       sandbox,axi
blk_partition
bootcount-rtc         u-boot,bootcount-rtc
...
rockchip_rk805        rockchip,rk805
                      rockchip,rk808
                      rockchip,rk809
                      rockchip,rk816
                      rockchip,rk817
                      rockchip,rk818
root_driver
rtc-rv8803            microcrystal,rv8803
                      epson,rx8803
                      epson,rx8900
...
wdt_gpio              linux,wdt-gpio
wdt_sandbox           sandbox,wdt

dm devres

This example shows an abridged version of the sandbox test output (running U-Boot with the -T flag):

=> dm devres
- root_driver
- demo_shape_drv
- demo_simple_drv
- demo_shape_drv
...
- h-test
- devres-test
    00000000130194e0 (100 byte) devm_kmalloc_release  BIND
- another-test
...
- syscon@3
- a-mux-controller
    0000000013025e60 (96 byte) devm_kmalloc_release  PROBE
    0000000013025f00 (24 byte) devm_kmalloc_release  PROBE
    0000000013026010 (24 byte) devm_kmalloc_release  PROBE
    0000000013026070 (24 byte) devm_kmalloc_release  PROBE
    00000000130260d0 (24 byte) devm_kmalloc_release  PROBE
- syscon@3
- a-mux-controller
    0000000013026150 (96 byte) devm_kmalloc_release  PROBE
    00000000130261f0 (24 byte) devm_kmalloc_release  PROBE
    0000000013026300 (24 byte) devm_kmalloc_release  PROBE
    0000000013026360 (24 byte) devm_kmalloc_release  PROBE
    00000000130263c0 (24 byte) devm_kmalloc_release  PROBE
- emul-mux-controller
    0000000013025fa0 (32 byte) devm_kmalloc_release  PROBE
- testfdtm0
- testfdtm1
...
- pinmux_spi0_pins
- pinmux_uart0_pins
- pinctrl-single-bits
    0000000013229180 (320 byte) devm_kmalloc_release  PROBE
    0000000013229300 (40 byte) devm_kmalloc_release  PROBE
    0000000013229370 (160 byte) devm_kmalloc_release  PROBE
    000000001322c190 (40 byte) devm_kmalloc_release  PROBE
    000000001322c200 (32 byte) devm_kmalloc_release  PROBE
- pinmux_i2c0_pins
...
- reg@0
- reg@1

dm drivers

This example shows an abridged version of the sandbox output:

=> dm drivers
Driver                    uid uclass               Devices
----------------------------------------------------------
act8846_reg               087 regulator            <none>
sandbox_adder             021 axi                  adder
                                                adder
axi_sandbox_bus           021 axi                  axi@0
...
da7219                    061 misc                 <none>
demo_shape_drv            001 demo                 demo_shape_drv
                                                demo_shape_drv
                                                demo_shape_drv
demo_simple_drv           001 demo                 demo_simple_drv
                                                demo_simple_drv
testfdt_drv               003 testfdt              a-test
                                                b-test
                                                d-test
                                                e-test
                                                f-test
                                                g-test
                                                another-test
                                                chosen-test
testbus_drv               005 testbus              some-bus
                                                mmio-bus@0
                                                mmio-bus@1
dsa-port                  039 ethernet             lan0
                                                lan1
dsa_sandbox               035 dsa                  dsa-test
eep_sandbox               121 w1_eeprom            <none>
...
pfuze100_regulator        087 regulator            <none>
phy_sandbox               077 phy                  bind-test-child1
                                                gen_phy@0
                                                gen_phy@1
                                                gen_phy@2
pinconfig                 078 pinconfig            gpios
                                                gpio0
                                                gpio1
                                                gpio2
                                                gpio3
                                                i2c
                                                groups
                                                pins
                                                i2s
                                                spi
                                                cs
                                                pinmux_pwm_pins
                                                pinmux_spi0_pins
                                                pinmux_uart0_pins
                                                pinmux_i2c0_pins
                                                pinmux_lcd_pins
pmc_sandbox               017 power-mgr            pci@1e,0
act8846 pmic              080 pmic                 <none>
max77686_pmic             080 pmic                 <none>
mc34708_pmic              080 pmic                 pmic@41
...
wdt_gpio                  122 watchdog             gpio-wdt
wdt_sandbox               122 watchdog             wdt@0
=>

dm mem

This example shows the sandbox output:

> dm mem
Struct sizes: udevice b0, driver 80, uclass 30, uc_driver 78
Memory: device fe:aea0, device names a16, uclass 5e:11a0

Attached type    Count   Size    Cur   Tags   Save
---------------  -----  -----  -----  -----  -----
plat                45    a8f   aea0   a7c4    6dc (1756)
parent_plat         1a    3b8   aea0   a718    788 (1928)
uclass_plat         3d    6b4   aea0   a7a4    6fc (1788)
priv                8a   68f3   aea0   a8d8    5c8 (1480)
parent_priv          8   38a0   aea0   a6d0    7d0 (2000)
uclass_priv         4e   14a6   aea0   a7e8    6b8 (1720)
driver_data          f      0   aea0   a6ec    7b4 (1972)
uclass               6     20
Attached total     191   cb54                  3164 (12644)
tags                 0      0

Total size: 18b94 (101268)

With tags:       15a30 (88624)
- singly-linked: 14260 (82528)
- driver index:  13b6e (80750)
- uclass index:  1347c (78972)
Drop device name (not SRAM): a16 (2582)
=>

dm static

This example shows the sandbox output:

=> dm static
Driver                    Address
---------------------------------
demo_shape_drv            0000562edab8dca0
demo_simple_drv           0000562edab8dca0
demo_shape_drv            0000562edab8dc90
demo_simple_drv           0000562edab8dc80
demo_shape_drv            0000562edab8dc80
test_drv                  0000562edaae8840
test_drv                  0000562edaae8848
test_drv                  0000562edaae8850
sandbox_gpio              0000000000000000
mod_exp_sw                0000000000000000
sandbox_test_proc         0000562edabb5330
qfw_sandbox               0000000000000000
sandbox_timer             0000000000000000
sandbox_serial            0000562edaa8ed00
sysreset_sandbox          0000000000000000

dm tree

This example shows the abridged sandbox output:

=> dm tree
Class     Index  Probed  Driver                Name
-----------------------------------------------------------
root          0  [ + ]   root_driver           root_driver
demo          0  [   ]   demo_shape_drv        |-- demo_shape_drv
demo          1  [   ]   demo_simple_drv       |-- demo_simple_drv
demo          2  [   ]   demo_shape_drv        |-- demo_shape_drv
demo          3  [   ]   demo_simple_drv       |-- demo_simple_drv
demo          4  [   ]   demo_shape_drv        |-- demo_shape_drv
test          0  [   ]   test_drv              |-- test_drv
test          1  [   ]   test_drv              |-- test_drv
test          2  [   ]   test_drv              |-- test_drv
..
sysreset      0  [   ]   sysreset_sandbox      |-- sysreset_sandbox
bootstd       0  [   ]   bootstd_drv           |-- bootstd
bootmeth      0  [   ]   bootmeth_distro       |   |-- syslinux
bootmeth      1  [   ]   bootmeth_efi          |   `-- efi
reboot-mod    0  [   ]   reboot-mode-gpio      |-- reboot-mode0
reboot-mod    1  [   ]   reboot-mode-rtc       |-- reboot-mode@14
...
ethernet      7  [ + ]   dsa-port              |   `-- lan1
pinctrl       0  [ + ]   sandbox_pinctrl_gpio  |-- pinctrl-gpio
gpio          1  [ + ]   sandbox_gpio          |   |-- base-gpios
nop           0  [ + ]   gpio_hog              |   |   |-- hog_input_active_low
nop           1  [ + ]   gpio_hog              |   |   |-- hog_input_active_high
nop           2  [ + ]   gpio_hog              |   |   |-- hog_output_low
nop           3  [ + ]   gpio_hog              |   |   `-- hog_output_high
gpio          2  [   ]   sandbox_gpio          |   |-- extra-gpios
gpio          3  [   ]   sandbox_gpio          |   `-- pinmux-gpios
i2c           0  [ + ]   sandbox_i2c           |-- i2c@0
i2c_eeprom    0  [   ]   i2c_eeprom            |   |-- eeprom@2c
i2c_eeprom    1  [   ]   i2c_eeprom_partition  |   |   `-- bootcount@10
rtc           0  [   ]   sandbox_rtc           |   |-- rtc@43
rtc           1  [ + ]   sandbox_rtc           |   |-- rtc@61
i2c_emul_p    0  [ + ]   sandbox_i2c_emul_par  |   |-- emul
i2c_emul      0  [   ]   sandbox_i2c_eeprom_e  |   |   |-- emul-eeprom
i2c_emul      1  [   ]   sandbox_i2c_rtc_emul  |   |   |-- emul0
i2c_emul      2  [ + ]   sandbox_i2c_rtc_emul  |   |   |-- emull
i2c_emul      3  [   ]   sandbox_i2c_pmic_emu  |   |   |-- pmic-emul0
i2c_emul      4  [   ]   sandbox_i2c_pmic_emu  |   |   `-- pmic-emul1
pmic          0  [   ]   sandbox_pmic          |   |-- sandbox_pmic
regulator     0  [   ]   sandbox_buck          |   |   |-- buck1
regulator     1  [   ]   sandbox_buck          |   |   |-- buck2
regulator     2  [   ]   sandbox_ldo           |   |   |-- ldo1
regulator     3  [   ]   sandbox_ldo           |   |   |-- ldo2
regulator     4  [   ]   sandbox_buck          |   |   `-- no_match_by_nodename
pmic          1  [   ]   mc34708_pmic          |   `-- pmic@41
bootcount     0  [ + ]   bootcount-rtc         |-- bootcount@0
bootcount     1  [   ]   bootcount-i2c-eeprom  |-- bootcount
...
clk           4  [   ]   fixed_clock           |-- osc
firmware      0  [   ]   sandbox_firmware      |-- sandbox-firmware
scmi_agent    0  [   ]   sandbox-scmi_agent    `-- scmi
clk           5  [   ]   scmi_clk                  |-- protocol@14
reset         2  [   ]   scmi_reset_domain         |-- protocol@16
nop           8  [   ]   scmi_voltage_domain       `-- regulators
regulator     5  [   ]   scmi_regulator                |-- reg@0
regulator     6  [   ]   scmi_regulator                `-- reg@1
=>

dm uclass

This example shows the abridged sandbox output:

=> dm uclass
uclass 0: root
0   * root_driver @ 03015460, seq 0

uclass 1: demo
0     demo_shape_drv @ 03015560, seq 0
1     demo_simple_drv @ 03015620, seq 1
2     demo_shape_drv @ 030156e0, seq 2
3     demo_simple_drv @ 030157a0, seq 3
4     demo_shape_drv @ 03015860, seq 4

uclass 2: test
0     test_drv @ 03015980, seq 0
1     test_drv @ 03015a60, seq 1
2     test_drv @ 03015b40, seq 2
...
uclass 20: audio-codec
0     audio-codec @ 030168e0, seq 0

uclass 21: axi
0     adder @ 0301db60, seq 1
1     adder @ 0301dc40, seq 2
2     axi@0 @ 030217d0, seq 0

uclass 22: blk
0     mmc2.blk @ 0301ca00, seq 0
1     mmc1.blk @ 0301cee0, seq 1
2     mmc0.blk @ 0301d380, seq 2

uclass 23: bootcount
0   * bootcount@0 @ 0301b3f0, seq 0
1     bootcount @ 0301b4b0, seq 1
2     bootcount_4@0 @ 0301b570, seq 2
3     bootcount_2@0 @ 0301b630, seq 3

uclass 24: bootdev
0     mmc2.bootdev @ 0301cbb0, seq 0
1     mmc1.bootdev @ 0301d050, seq 1
2     mmc0.bootdev @ 0301d4f0, seq 2

...
uclass 78: pinconfig
0     gpios @ 03022410, seq 0
1     gpio0 @ 030224d0, seq 1
2     gpio1 @ 03022590, seq 2
3     gpio2 @ 03022650, seq 3
4     gpio3 @ 03022710, seq 4
5     i2c @ 030227d0, seq 5
6     groups @ 03022890, seq 6
7     pins @ 03022950, seq 7
8     i2s @ 03022a10, seq 8
9     spi @ 03022ad0, seq 9
10    cs @ 03022b90, seq 10
11    pinmux_pwm_pins @ 03022e10, seq 11
12    pinmux_spi0_pins @ 03022ed0, seq 12
13    pinmux_uart0_pins @ 03022f90, seq 13
14  * pinmux_i2c0_pins @ 03023130, seq 14
15  * pinmux_lcd_pins @ 030231f0, seq 15

...
uclass 119: virtio
0     sandbox_virtio1 @ 030220d0, seq 0
1     sandbox_virtio2 @ 03022190, seq 1

uclass 120: w1
uclass 121: w1_eeprom
uclass 122: watchdog
0   * gpio-wdt @ 0301c070, seq 0
1   * wdt@0 @ 03021710, seq 1

=>