? - Show Internal Command Help or Evaluate an Expression

Display help for internal Kernel Debugger and Dump Formatter commands and evaluate complex expressions.

Syntax:

───── ? ──┬─────────────────┬──────────────────────────────────
           ├───   expr    ───┤
           └───  string   ───┘

Parameters:

• default)
  Displays a help summary for most of the Dump Formatter and Kernel Debugger internal commands.

  Note:

  Some of the information displayed is out-of-date.

  Two pages of information are displayed with an intervening --More-- prompt.

  expr
  An expression that resolves to either a simple numeric value or an address using any of the expression evaluation operators. Symbols of addresses and symbols of absolute values may be specified.
  string
  A string enclosed in single or double quotes.

  Results & Notes:

  If an expression is specified then it is evaluated. If it resolves to an address then it is displayed in equivalent forms, as follows:

  sel:offset %linaddr %%physaddr

  Where:

  sel:offset

  Specifies the selector and offset form of the address if the expression resolves to a sel:offset form.
  %linaddr
  Specifies the linear address equivalent of the expression if it resolves to either a sel:offset or %linaddr form.
  %physaddr
  Specifies the physical address equivalent of the expression. If the expression resolves to a virtual address then the page tables must be present to perform the address translation.

  See the DP command for information on displaying page table entries and the .I command for information on paging in memory.

  if the evaluated expression resolves to an absolute value then it is displayed in hexadecimal, decimal, octal, binary, character and boolean forms. For example:

  -------------------------------------------------------------------------------##? 5
  05H 5T 5Q 00000101Y '.' TRUE
  ? bmp_segsize
  12H 18T 22Q 00010010Y '.' TRUE
  -------------------------------------------------------------------------------
  

  Notes

  Each arithmetic value is suffixed with a modifier that indicates the base used:

  H

  Signifies hexadecimal
  T
  Signifies decimal (Tens)
  Q
  Signifies octal (Qctal?)
  Y
  Signifies binary (Yes/no?)

  In the last example above, bmp_segsize is an absolute symbol of value 0x0012 defined in map OS2KRNL.

  If a string expression is displayed then it is echoed back to the console. For example:

  -------------------------------------------------------------------------------##? "This is a way of anotating the debug log from this session's analysis"
  This is a way of annotating the debug log from this session's analysis
  
  ##
  -------------------------------------------------------------------------------
  

  Note:

  Evaluation of simple expressions involving two absolute expressions may be done using the H command.

  ---

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