--- /dev/null
+.. SPDX-License-Identifier: GPL-2.0+
+
+.. index::
+ single: itest (command)
+
+itest command
+=============
+
+Synopsis
+--------
+
+::
+
+ itest[.b | .w | .l | .q | .s] [*]<value1> <op> [*]<value2>
+
+Description
+-----------
+
+The itest command is used to compare two values. The return value $? is set
+accordingly.
+
+By default it is assumed that the values are 4 byte integers. By appending a
+postfix (.b, .w, .l, .q, .s) the size can be specified:
+
+======= ======================================================
+postfix meaning
+======= ======================================================
+.b 1 byte integer
+.w 2 byte integer
+.l 4 byte integer
+.q 8 byte integer (only available if CONFIG_PHYS_64BIT=y)
+.s string
+======= ======================================================
+
+value1, value2
+ values to compare. Numeric values are hexadecimal. If '*' is prefixed a
+ hexadecimal address is passed, which points to the value to be compared.
+
+op
+ operator, see table
+
+ ======== ======================
+ operator meaning
+ ======== ======================
+ -lt less than
+ < less than
+ -le less or equal
+ <= less or equal
+ -eq equal
+ == equal
+ -ne not equal
+ != not equal
+ <> not equal
+ -ge greater or equal
+ >= greater or equal
+ -gt greater than
+ > greater than
+ ======== ======================
+
+Examples
+========
+
+The itest command sets the result variable $? to true (0) or false (1):
+
+::
+
+ => itest 3 < 4; echo $?
+ 0
+ => itest 3 == 4; echo $?
+ 1
+
+This value can be used in the :doc:`if <if>` command:
+
+::
+
+ => if itest 0x3002 < 0x4001; then echo true; else echo false; fi
+ true
+
+Numbers will be truncated according to the postfix before comparing:
+
+::
+
+ => if itest.b 0x3002 < 0x4001; then echo true; else echo false; fi
+ false
+
+Postfix .s causes a string compare. The string '0xa1234' is alphabetically
+smaller than '0xb'.
+
+ => if itest.s 0xa1234 < 0xb; then echo true; else echo false; fi
+ true
+
+A value prefixed by '*' is a pointer to the value in memory.
+
+::
+
+ => mm 0x4000
+ 00004000: 00000004 ?
+ 00004004: 00000003 ? =>
+ => if itest *0x4000 == 4; then echo true; else echo false; fi
+ true
+ => if itest *0x4004 == 3; then echo true; else echo false; fi
+ true
+
+Configuration
+-------------
+
+The command is only available if CONFIG_CMD_ITEST=y.
+
+Return value
+------------
+
+The return value $? is 0 (true) if the condition is true and 1 (false)
+otherwise.