| Address |  | Virtual Address Main Memory (MM) |
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KDB commands can only be entered when KDB is in supervisory mode. The command is entered after month day hour:min:sec node:KDB: is displayed on the terminal.
Upper or lowercase letters are allowed for the command name, numeric, register name, and option character. There is a distinction made between upper and lowercase letters for symbolic name.
The following is KDB command format.
where
| command name | |
| The KDB command. | |
| address | Indicates the target address. Address format is discussed further in Section 3.3. |
| option | These parameters are command dependent. |
| [ ] | Parameters enclosed in brackets are optional. Do not type the brackets ([ ]) when entering the command. To do so causes an error. |
| | | This symbol indicates that there is a choice of specifications. The characters that appear before or after the | can be used. Do not type the symbol (|) when entering the command. To do so causes an error. |
| ; | Commands can be separated by semi-colons (;). This is known as multicommand. Execution begins with the left-most command. If an error is detected during execution, the commands following the one containing the error are ignored. (This does not apply to the command sequence that is followed by TRP. See Section 4.2 for details.) |
The maximum number of characters allowed per line is 76.
If a command does not fit on one line, add a hyphen (-) at the end of the line or press CNT instead of Execute. This allows the command line to continue on the next line. The maximum number of characters allowed per command is 130; the total number of lines is 5.
To repeat a command sequence, add ";*" at the end of the command sequence. This reexecutes the sequence until a suspension is indicated. See Section 3.4 for more information about suspending command execution.
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All the numeric values in a KDB command are hexadecimal numbers except for the register number, which is a decimal. Upper or lowercase letters are allowed for hexadecimal numbers a to f. There are several rules for specifying the numeric values in hex.
Example:
| + | Add |
| - | Subtract |
| * | Multiply |
| < | Left shift |
| > | Right shift |
The following example is equivalent to (8 + 2) * 3 (which equals 30).
Example:
The addresses used in KDB commands are classified as follows.
| Address | | Virtual Address Main Memory (MM) |
Individual address formats are explained in the following sections.
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Format:
where
| * | Means indirect addressing. Up to a maximum of 16 levels can be specified. Ignore the tag in the pointer. |
| PID | Specifies the process ID. |
| [n] | Specifies the proc table entry number that manages the PID. The brackets ( [ ] ) must be entered. |
| TID | Specifies the task ID.
When both the PID ( [n]) and TID are omitted, PID ([n]) of the current process and TID of the current task are assumed for the trap function. Previously displayed PID ([n]) and TID are assumed for the display function, or PID ([n]) and TID previously specified for the patch command are assumed for the patch function. When only PID ([n]) is omitted, TID specified here is in effect and PID ([n]) of the current process is assumed for the trap function. Previously displayed PID ([n]) is assumed for the display function, or PID ([n]) specified for the patch command is assumed for the patch function. When only TID is omitted, PID ([n]) specified here is in effect and TID of the current task is assumed for the trap function. Previously displayed TID is assumed for the display function, or TID previously specified for the patch command is assumed for the patch function. |
| ptr | Specifies the address in virtual address space. Address format is discussed in Section 3.3.3. |
The main memory (MM) absolute address specifies the location in physical MM.
Format:
where
| * | Means indirect addressing. |
| ptr | Specifies the address in MM physical address space. Address format is discussed in Section 3.3.3. |
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Two types of specification, symbolic and numeric, are possible for ptr of each address.
Format:
where
| & | Key character that indicates symbolic specification. It can be omitted if an underbar (_), a character from g to z, or a character from G to Z is one of the symbolic names. |
| symbol name | |
| The name in the symbol table of the kernel. This table maps function names and
external variable names to corresponding addresses.
A distinction between upper and lowercase is made for a symbol name. | |
| + | - numeric values | |
 | Add (+) or subtract (-) numeric values to/from the symbol table address. |
Format:
where
| + | - numeric values | |
| Add (+) or subtract (-) the following numeric values to/from the current effective address. If the + | - symbol is omitted, the current effective address is bypassed and the address is specified by the numeric value entered. With the trap command, the default address is the one displayed at the IC message when KDB is activated. With the display or patch command, it is the address created by adding display length or patch length to the address specified by the previous display or patch function. |
Press the ATT key to suspend an executing command.
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