Sakamoto, Yoshinori Sato, Michael Snyder, Corinna Vinschen, and Ulrich
Weigand.
+Christian Zankel, Ross Morley, Bob Wilson, and Maxim Grigoriev from
+Tensilica, Inc.@: contributed support for Xtensa processors. Others
+who have worked on the Xtensa port of @value{GDBN} in the past include
+Steve Tjiang, John Newlin, and Scott Foehner.
+
@node Sample Session
@chapter A Sample @value{GDBN} Session
@b{define(baz,defn(<QUOTE>foo<UNQUOTE>))}
@b{baz}
-@b{C-d}
+@b{Ctrl-d}
m4: End of input: 0: fatal error: EOF in string
@end smallexample
lengths. We allow @code{m4} exit by giving it an EOF as input:
@smallexample
-@b{C-d}
+@b{Ctrl-d}
Program exited normally.
@end smallexample
@item
type @samp{@value{GDBP}} to start @value{GDBN}.
@item
-type @kbd{quit} or @kbd{C-d} to exit.
+type @kbd{quit} or @kbd{Ctrl-d} to exit.
@end itemize
@menu
@item quit @r{[}@var{expression}@r{]}
@itemx q
To exit @value{GDBN}, use the @code{quit} command (abbreviated
-@code{q}), or type an end-of-file character (usually @kbd{C-d}). If you
+@code{q}), or type an end-of-file character (usually @kbd{Ctrl-d}). If you
do not supply @var{expression}, @value{GDBN} will terminate normally;
otherwise it will terminate using the result of @var{expression} as the
error code.
@end table
@cindex interrupt
-An interrupt (often @kbd{C-c}) does not exit from @value{GDBN}, but rather
+An interrupt (often @kbd{Ctrl-c}) does not exit from @value{GDBN}, but rather
terminates the action of any @value{GDBN} command that is in progress and
returns to @value{GDBN} command level. It is safe to type the interrupt
character at any time because @value{GDBN} does not allow it to take effect
Files,,Command files}).
@cindex repeating command sequences
-@kindex C-o @r{(operate-and-get-next)}
-The @kbd{C-o} binding is useful for repeating a complex sequence of
-commands. This command accepts the current line, like @kbd{RET}, and
+@kindex Ctrl-o @r{(operate-and-get-next)}
+The @kbd{Ctrl-o} binding is useful for repeating a complex sequence of
+commands. This command accepts the current line, like @key{RET}, and
then fetches the next line relative to the current line from the history
for editing.
@end table
To quit debugging one of the forked processes, you can either detach
-from it by using the @w{@code{detach-fork}} command (allowing it to
+from it by using the @w{@code{detach fork}} command (allowing it to
run independently), or delete (and kill) it using the
@w{@code{delete fork}} command.
@table @code
-@kindex detach-fork @var{fork-id}
-@item detach-fork @var{fork-id}
+@kindex detach fork @var{fork-id}
+@item detach fork @var{fork-id}
Detach from the process identified by @value{GDBN} fork number
@var{fork-id}, and remove it from the fork list. The process will be
allowed to run independently.
call).
@cindex watchpoints
+@cindex data breakpoints
@cindex memory tracing
@cindex breakpoint on memory address
@cindex breakpoint on variable modification
A @dfn{watchpoint} is a special breakpoint that stops your program
-when the value of an expression changes. You must use a different
-command to set watchpoints (@pxref{Set Watchpoints, ,Setting
-watchpoints}), but aside from that, you can manage a watchpoint like
-any other breakpoint: you enable, disable, and delete both breakpoints
-and watchpoints using the same commands.
+when the value of an expression changes. The expression may be a value
+of a variable, or it could involve values of one or more variables
+combined by operators, such as @samp{a + b}. This is sometimes called
+@dfn{data breakpoints}. You must use a different command to set
+watchpoints (@pxref{Set Watchpoints, ,Setting watchpoints}), but aside
+from that, you can manage a watchpoint like any other breakpoint: you
+enable, disable, and delete both breakpoints and watchpoints using the
+same commands.
You can arrange to have values from your program displayed automatically
whenever @value{GDBN} stops at a breakpoint. @xref{Auto Display,,
@itemx info break @r{[}@var{n}@r{]}
@itemx info watchpoints @r{[}@var{n}@r{]}
Print a table of all breakpoints, watchpoints, and catchpoints set and
-not deleted, with the following columns for each breakpoint:
+not deleted. Optional argument @var{n} means print information only
+about the specified breakpoint (or watchpoint or catchpoint). For
+each breakpoint, following columns are printed:
@table @emph
@item Breakpoint Numbers
@cindex setting watchpoints
You can use a watchpoint to stop execution whenever the value of an
expression changes, without having to predict a particular place where
-this may happen.
+this may happen. (This is sometimes called a @dfn{data breakpoint}.)
+The expression may be as simple as the value of a single variable, or
+as complex as many variables combined by operators. Examples include:
+
+@itemize @bullet
+@item
+A reference to the value of a single variable.
+
+@item
+An address cast to an appropriate data type. For example,
+@samp{*(int *)0x12345678} will watch a 4-byte region at the specified
+address (assuming an @code{int} occupies 4 bytes).
+
+@item
+An arbitrarily complex expression, such as @samp{a*b + c/d}. The
+expression can use any operators valid in the program's native
+language (@pxref{Languages}).
+@end itemize
@cindex software watchpoints
@cindex hardware watchpoints
@table @code
@kindex watch
@item watch @var{expr}
-Set a watchpoint for an expression. @value{GDBN} will break when @var{expr}
-is written into by the program and its value changes.
+Set a watchpoint for an expression. @value{GDBN} will break when the
+expression @var{expr} is written into by the program and its value
+changes. The simplest (and the most popular) use of this command is
+to watch the value of a single variable:
+
+@smallexample
+(@value{GDBP}) watch foo
+@end smallexample
@kindex rwatch
@item rwatch @var{expr}
Set a watchpoint that will break when @var{expr} is either read from
or written into by the program.
-@kindex info watchpoints
+@kindex info watchpoints @r{[}@var{n}@r{]}
@item info watchpoints
This command prints a list of watchpoints, breakpoints, and catchpoints;
it is the same as @code{info break} (@pxref{Set Breaks}).
@noindent
If this happens, delete or disable some of the watchpoints.
+Watching complex expressions that reference many variables can also
+exhaust the resources available for hardware-assisted watchpoints.
+That's because @value{GDBN} needs to watch every variable in the
+expression with separately allocated resources.
+
The SPARClite DSU will generate traps when a program accesses some data
or instruction address that is assigned to the debug registers. For the
data addresses, DSU facilitates the @code{watch} command. However the
A signal is an asynchronous event that can happen in a program. The
operating system defines the possible kinds of signals, and gives each
kind a name and a number. For example, in Unix @code{SIGINT} is the
-signal a program gets when you type an interrupt character (often @kbd{C-c});
+signal a program gets when you type an interrupt character (often @kbd{Ctrl-c});
@code{SIGSEGV} is the signal a program gets from referencing a place in
memory far away from all the areas in use; @code{SIGALRM} occurs when
the alarm clock timer goes off (which happens only if your program has
handle each one. You can use this to see the signal numbers of all
the defined types of signals.
+@item info signals @var{sig}
+Similar, but print information only about the specified signal number.
+
@code{info handle} is an alias for @code{info signals}.
@kindex handle
-@item handle @var{signal} @var{keywords}@dots{}
+@item handle @var{signal} @r{[}@var{keywords}@dots{}@r{]}
Change the way @value{GDBN} handles signal @var{signal}. @var{signal}
can be the number of a signal or its name (with or without the
@samp{SIG} at the beginning); a list of signal numbers of the form
@samp{@var{low}-@var{high}}; or the word @samp{all}, meaning all the
-known signals. The @var{keywords} say what change to make.
+known signals. Optional arguments @var{keywords}, described below,
+say what change to make.
@end table
@c @group
frames in the stack.
You can stop the backtrace at any time by typing the system interrupt
-character, normally @kbd{C-c}.
+character, normally @kbd{Ctrl-c}.
@item backtrace @var{n}
@itemx bt @var{n}
Similar, but print only the outermost @var{n} frames.
@item backtrace full
-Print the values of the local variables also.
@itemx bt full
+@itemx bt full @var{n}
+@itemx bt full -@var{n}
+Print the values of the local variables also. @var{n} specifies the
+number of frames to print, as described above.
@end table
@kindex where
The search path is used to find both program source files and @value{GDBN}
script files (read using the @samp{-command} option and @samp{source} command).
+In addition to the source path, @value{GDBN} provides a set of commands
+that manage a list of source path substitution rules. A @dfn{substitution
+rule} specifies how to rewrite source directories stored in the program's
+debug information in case the sources were moved to a different
+directory between compilation and debugging. A rule is made of
+two strings, the first specifying what needs to be rewritten in
+the path, and the second specifying how it should be rewritten.
+In @ref{set substitute-path}, we name these two parts @var{from} and
+@var{to} respectively. @value{GDBN} does a simple string replacement
+of @var{from} with @var{to} at the start of the directory part of the
+source file name, and uses that result instead of the original file
+name to look up the sources.
+
+Using the previous example, suppose the @file{foo-1.0} tree has been
+moved from @file{/usr/src} to @file{/mnt/cross}, then you can tell
+GDB to replace @file{/usr/src} in all source path names with
+@file{/mnt/cross}. The first lookup will then be
+@file{/mnt/cross/foo-1.0/lib/foo.c} in place of the original location
+of @file{/usr/src/foo-1.0/lib/foo.c}. To define a source path
+substitution rule, use the @code{set substitute-path} command
+(@pxref{set substitute-path}).
+
+To avoid unexpected substitution results, a rule is applied only if the
+@var{from} part of the directory name ends at a directory separator.
+For instance, a rule substituting @file{/usr/source} into
+@file{/mnt/cross} will be applied to @file{/usr/source/foo-1.0} but
+not to @file{/usr/sourceware/foo-2.0}. And because the substitution
+is applied only at the begining of the directory name, this rule will
+not be applied to @file{/root/usr/source/baz.c} either.
+
+In many cases, you can achieve the same result using the @code{directory}
+command. However, @code{set substitute-path} can be more efficient in
+the case where the sources are organized in a complex tree with multiple
+subdirectories. With the @code{directory} command, you need to add each
+subdirectory of your project. If you moved the entire tree while
+preserving its internal organization, then @code{set substitute-path}
+allows you to direct the debugger to all the sources with one single
+command.
+
+@code{set substitute-path} is also more than just a shortcut command.
+The source path is only used if the file at the original location no
+longer exists. On the other hand, @code{set substitute-path} modifies
+the debugger behavior to look at the rewritten location instead. So, if
+for any reason a source file that is not relevant to your executable is
+located at the original location, a substitution rule is the only
+method available to point GDB at the new location.
+
@table @code
@item directory @var{dirname} @dots{}
@item dir @var{dirname} @dots{}
@item show directories
@kindex show directories
Print the source path: show which directories it contains.
+
+@anchor{set substitute-path}
+@item set substitute-path @var{from} @var{to}
+@kindex set substitute-path
+Define a source path substitution rule, and add it at the end of the
+current list of existing substitution rules. If a rule with the same
+@var{from} was already defined, then the old rule is also deleted.
+
+For example, if the file @file{/foo/bar/baz.c} was moved to
+@file{/mnt/cross/baz.c}, then the command
+
+@smallexample
+(@value{GDBP}) set substitute-path /usr/src /mnt/cross
+@end smallexample
+
+@noindent
+will tell @value{GDBN} to replace @samp{/usr/src} with
+@samp{/mnt/cross}, which will allow @value{GDBN} to find the file
+@file{baz.c} even though it was moved.
+
+In the case when more than one substitution rule have been defined,
+the rules are evaluated one by one in the order where they have been
+defined. The first one matching, if any, is selected to perform
+the substitution.
+
+For instance, if we had entered the following commands:
+
+@smallexample
+(@value{GDBP}) set substitute-path /usr/src/include /mnt/include
+(@value{GDBP}) set substitute-path /usr/src /mnt/src
+@end smallexample
+
+@noindent
+@value{GDBN} would then rewrite @file{/usr/src/include/defs.h} into
+@file{/mnt/include/defs.h} by using the first rule. However, it would
+use the second rule to rewrite @file{/usr/src/lib/foo.c} into
+@file{/mnt/src/lib/foo.c}.
+
+
+@item unset substitute-path [path]
+@kindex unset substitute-path
+If a path is specified, search the current list of substitution rules
+for a rule that would rewrite that path. Delete that rule if found.
+A warning is emitted by the debugger if no rule could be found.
+
+If no path is specified, then all substitution rules are deleted.
+
+@item show substitute-path [path]
+@kindex show substitute-path
+If a path is specified, then print the source path substitution rule
+which would rewrite that path, if any.
+
+If no path is specified, then print all existing source path substitution
+rules.
+
@end table
If your source path is cluttered with directories that are no longer of
Depending on the configuration and operating system facilities,
@value{GDBN} may be able to show you this information. For remote
targets, this functionality may further depend on the remote stub's
-support of the @samp{qXfer:auxv:read} packet, see @ref{Remote
-configuration, auxiliary vector}.
+support of the @samp{qXfer:auxv:read} packet, see
+@ref{qXfer auxiliary vector read}.
@table @code
@kindex info auxv
@cindex memory region attributes
@dfn{Memory region attributes} allow you to describe special handling
-required by regions of your target's memory. @value{GDBN} uses attributes
-to determine whether to allow certain types of memory accesses; whether to
-use specific width accesses; and whether to cache target memory.
+required by regions of your target's memory. @value{GDBN} uses
+attributes to determine whether to allow certain types of memory
+accesses; whether to use specific width accesses; and whether to cache
+target memory. By default the description of memory regions is
+fetched from the target (if the current target supports this), but the
+user can override the fetched regions.
Defined memory regions can be individually enabled and disabled. When a
memory region is disabled, @value{GDBN} uses the default attributes when
case: it is treated as the the target's maximum memory address.
(0xffff on 16 bit targets, 0xffffffff on 32 bit targets, etc.)
+@item mem auto
+Discard any user changes to the memory regions and use target-supplied
+regions, if available, or no regions if the target does not support.
+
@kindex delete mem
@item delete mem @var{nums}@dots{}
Remove memory regions @var{nums}@dots{} from the list of regions
specifies a fixed address.
@c FIXME! This would be a good place for an xref to the GNU linker doc.
+Depending on the remote side capabilities, @value{GDBN} may be able to
+load programs into flash memory.
+
@code{load} does not repeat if you press @key{RET} again after using it.
@end table
@cindex interrupting remote programs
@cindex remote programs, interrupting
Whenever @value{GDBN} is waiting for the remote program, if you type the
-interrupt character (often @key{C-C}), @value{GDBN} attempts to stop the
+interrupt character (often @kbd{Ctrl-c}), @value{GDBN} attempts to stop the
program. This may or may not succeed, depending in part on the hardware
and the serial drivers the remote system uses. If you type the
interrupt character once again, @value{GDBN} displays this prompt:
@cindex BREAK signal instead of Ctrl-C
@anchor{set remotebreak}
If set to on, @value{GDBN} sends a @code{BREAK} signal to the remote
-when you press the @key{Ctrl-C} key to interrupt the program running
+when you type @kbd{Ctrl-c} to interrupt the program running
on the remote. If set to off, @value{GDBN} sends the @samp{Ctrl-C}
character instead. The default is off, since most remote systems
expect to see @samp{Ctrl-C} as the interrupt signal.
@itemx set remote hardware-breakpoint-limit @var{limit}
Restrict @value{GDBN} to using @var{limit} remote hardware breakpoint or
watchpoints. A limit of -1, the default, is treated as unlimited.
+@end table
-@item set remote fetch-register-packet
-@itemx set remote set-register-packet
-@itemx set remote P-packet
-@itemx set remote p-packet
-@cindex P-packet
-@cindex fetch registers from remote targets
-@cindex set registers in remote targets
-Determine whether @value{GDBN} can set and fetch registers from the
-remote target using the @samp{P} packets. The default depends on the
-remote stub's support of the @samp{P} packets (@value{GDBN} queries
-the stub when this packet is first required).
-
-@item show remote fetch-register-packet
-@itemx show remote set-register-packet
-@itemx show remote P-packet
-@itemx show remote p-packet
-Show the current setting of using the @samp{P} packets for setting and
-fetching registers from the remote target.
-
-@cindex binary downloads
-@cindex X-packet
-@item set remote binary-download-packet
-@itemx set remote X-packet
-Determine whether @value{GDBN} sends downloads in binary mode using
-the @samp{X} packets. The default is on.
-
-@item show remote binary-download-packet
-@itemx show remote X-packet
-Show the current setting of using the @samp{X} packets for binary
-downloads.
-
-@item set remote read-aux-vector-packet
-@cindex auxiliary vector of remote target
-@cindex @code{auxv}, and remote targets
-Set the use of the remote protocol's @samp{qXfer:auxv:read} (target
-auxiliary vector) request. This request is used to fetch the
-remote target's @dfn{auxiliary vector}, see @ref{OS Information,
-Auxiliary Vector}. The default setting depends on the remote stub's
-support of this request (@value{GDBN} queries the stub when this
-request is first required). @xref{General Query Packets, qXfer}, for
-more information about this request.
-
-@item show remote read-aux-vector-packet
-Show the current setting of use of the @samp{qXfer:auxv:read} request.
-
-@item set remote symbol-lookup-packet
-@cindex remote symbol lookup request
-Set the use of the remote protocol's @samp{qSymbol} (target symbol
-lookup) request. This request is used to communicate symbol
-information to the remote target, e.g., whenever a new shared library
-is loaded by the remote (@pxref{Files, shared libraries}). The
-default setting depends on the remote stub's support of this request
-(@value{GDBN} queries the stub when this request is first required).
-@xref{General Query Packets, qSymbol}, for more information about this
-request.
+@cindex remote packets, enabling and disabling
+The @value{GDBN} remote protocol autodetects the packets supported by
+your debugging stub. If you need to override the autodetection, you
+can use these commands to enable or disable individual packets. Each
+packet can be set to @samp{on} (the remote target supports this
+packet), @samp{off} (the remote target does not support this packet),
+or @samp{auto} (detect remote target support for this packet). They
+all default to @samp{auto}. For more information about each packet,
+see @ref{Remote Protocol}.
-@item show remote symbol-lookup-packet
-Show the current setting of use of the @samp{qSymbol} request.
-
-@item set remote verbose-resume-packet
-@cindex resume remote target
-@cindex signal thread, and remote targets
-@cindex single-step thread, and remote targets
-@cindex thread-specific operations on remote targets
-Set the use of the remote protocol's @samp{vCont} (descriptive resume)
-request. This request is used to resume specific threads in the
-remote target, and to single-step or signal them. The default setting
-depends on the remote stub's support of this request (@value{GDBN}
-queries the stub when this request is first required). This setting
-affects debugging of multithreaded programs: if @samp{vCont} cannot be
-used, @value{GDBN} might be unable to single-step a specific thread,
-especially under @code{set scheduler-locking off}; it is also
-impossible to pause a specific thread. @xref{Packets, vCont}, for
-more details.
-
-@item show remote verbose-resume-packet
-Show the current setting of use of the @samp{vCont} request
-
-@item set remote software-breakpoint-packet
-@itemx set remote hardware-breakpoint-packet
-@itemx set remote write-watchpoint-packet
-@itemx set remote read-watchpoint-packet
-@itemx set remote access-watchpoint-packet
-@itemx set remote Z-packet
-@cindex Z-packet
-@cindex remote hardware breakpoints and watchpoints
-These commands enable or disable the use of @samp{Z} packets for
-setting breakpoints and watchpoints in the remote target. The default
-depends on the remote stub's support of the @samp{Z} packets
-(@value{GDBN} queries the stub when each packet is first required).
-The command @code{set remote Z-packet}, kept for back-compatibility,
-turns on or off all the features that require the use of @samp{Z}
-packets.
-
-@item show remote software-breakpoint-packet
-@itemx show remote hardware-breakpoint-packet
-@itemx show remote write-watchpoint-packet
-@itemx show remote read-watchpoint-packet
-@itemx show remote access-watchpoint-packet
-@itemx show remote Z-packet
-Show the current setting of @samp{Z} packets usage.
-
-@item set remote get-thread-local-storage-address
-@kindex set remote get-thread-local-storage-address
-@cindex thread local storage of remote targets
-This command enables or disables the use of the @samp{qGetTLSAddr}
-(Get Thread Local Storage Address) request packet. The default
-depends on whether the remote stub supports this request.
-@xref{General Query Packets, qGetTLSAddr}, for more details about this
-packet.
+During normal use, you should not have to use any of these commands.
+If you do, that may be a bug in your remote debugging stub, or a bug
+in @value{GDBN}. You may want to report the problem to the
+@value{GDBN} developers.
-@item show remote get-thread-local-storage-address
-@kindex show remote get-thread-local-storage-address
-Show the current setting of @samp{qGetTLSAddr} packet usage.
+The available settings are:
-@item set remote supported-packets
-@kindex set remote supported-packets
-@cindex query supported packets of remote targets
-This command enables or disables the use of the @samp{qSupported}
-request packet. @xref{General Query Packets, qSupported}, for more
-details about this packet. The default is to use @samp{qSupported}.
+@multitable @columnfractions 0.3 0.2 0.35
+@item Command Name
+@tab Remote Packet
+@tab Related Features
-@item show remote supported-packets
-@kindex show remote supported-packets
-Show the current setting of @samp{qSupported} packet usage.
-@end table
+@item @code{fetch-register-packet}
+@tab @code{p}
+@tab @code{info registers}
+
+@item @code{set-register-packet}
+@tab @code{P}
+@tab @code{set}
+
+@item @code{binary-download-packet}
+@tab @code{X}
+@tab @code{load}, @code{set}
+
+@item @code{read-aux-vector-packet}
+@tab @code{qXfer:auxv:read}
+@tab @code{info auxv}
+
+@item @code{symbol-lookup-packet}
+@tab @code{qSymbol}
+@tab Detecting multiple threads
+
+@item @code{verbose-resume-packet}
+@tab @code{vCont}
+@tab Stepping or resuming multiple threads
+
+@item @code{software-breakpoint-packet}
+@tab @code{Z0}
+@tab @code{break}
+
+@item @code{hardware-breakpoint-packet}
+@tab @code{Z1}
+@tab @code{hbreak}
+
+@item @code{write-watchpoint-packet}
+@tab @code{Z2}
+@tab @code{watch}
+
+@item @code{read-watchpoint-packet}
+@tab @code{Z3}
+@tab @code{rwatch}
+
+@item @code{access-watchpoint-packet}
+@tab @code{Z4}
+@tab @code{awatch}
+
+@item @code{get-thread-local-storage-address-packet}
+@tab @code{qGetTLSAddr}
+@tab Displaying @code{__thread} variables
+
+@item @code{supported-packets}
+@tab @code{qSupported}
+@tab Remote communications parameters
+
+@end multitable
@node remote stub
@section Implementing a remote stub
This boolean value controls whether the debuggee should
start a new group or stay in the same group as the debugger.
This affects the way the Windows OS handles
-Ctrl-C.
+@samp{Ctrl-C}.
@kindex show new-group
@item show new-group
Use the @sc{reset} button on the development board
@itemize @bullet
@item
-to interrupt your program (don't use @kbd{ctl-C} on the DOS host---it has
+to interrupt your program (don't use @kbd{Ctrl-c} on the DOS host---it has
no way to pass an interrupt signal to the development board); and
@item
Connect the controlling terminal to the STDBUG command monitor. When
you are done interacting with STDBUG, typing either of two character
sequences gets you back to the @value{GDBN} command prompt:
-@kbd{@key{RET}~.} (Return, followed by tilde and period) or
-@kbd{@key{RET}~@key{C-d}} (Return, followed by tilde and control-D).
+@kbd{@key{RET} ~ .} (Return, followed by tilde and period) or
+@kbd{@key{RET} ~ Ctrl-d} (Return, followed by tilde and control-D).
@end table
@node Z8000
for scrolling. This means they are available for readline when the
active window is the command window. When the command window
does not have the focus, it is necessary to use other readline
-key bindings such as @key{C-p}, @key{C-n}, @key{C-b} and @key{C-f}.
+key bindings such as @kbd{C-p}, @kbd{C-n}, @kbd{C-b} and @kbd{C-f}.
@node TUI Single Key Mode
@section TUI Single Key Mode
it is possible to type most @value{GDBN} commands without interaction
with the TUI @emph{SingleKey} mode. Once the command is entered the TUI
@emph{SingleKey} mode is restored. The only way to permanently leave
-this mode is by hitting @key{q} or @samp{@key{C-x} @key{s}}.
+this mode is by typing @kbd{q} or @kbd{C-x s}.
@node TUI Commands
@item refresh
@kindex refresh
-Refresh the screen. This is similar to using @key{C-L} key.
+Refresh the screen. This is similar to typing @kbd{C-L}.
@item tui reg float
@kindex tui reg
@value{GDBN} @code{down} command.
@end table
-In any source file, the Emacs command @kbd{C-x SPC} (@code{gud-break})
+In any source file, the Emacs command @kbd{C-x @key{SPC}} (@code{gud-break})
tells @value{GDBN} to set a breakpoint on the source line point is on.
If you type @kbd{M-x speedbar}, then Emacs displays a separate frame which
Display a list of the arguments for the frames between @var{low-frame}
and @var{high-frame} (inclusive). If @var{low-frame} and
-@var{high-frame} are not provided, list the arguments for the whole call
-stack.
+@var{high-frame} are not provided, list the arguments for the whole
+call stack. If the two arguments are equal, show the single frame
+at the corresponding level. It is an error if @var{low-frame} is
+larger than the actual number of frames. On the other hand,
+@var{high-frame} may be larger than the actual number of frames, in
+which case only existing frames will be returned.
The @var{show-values} argument must have a value of 0 or 1. A value of
0 means that only the names of the arguments are listed, a value of 1
If invoked without arguments, this command prints a backtrace for the
whole stack. If given two integer arguments, it shows the frames whose
levels are between the two arguments (inclusive). If the two arguments
-are equal, it shows the single frame at the corresponding level.
+are equal, it shows the single frame at the corresponding level. It is
+an error if @var{low-frame} is larger than the actual number of
+frames. On the other hand, @var{high-frame} may be larger than the
+actual number of frames, in which case only existing frames will be returned.
@subsubheading @value{GDBN} Command
The input types are
@table @code
-@findex pre-prompt
-@findex prompt
-@findex post-prompt
+@findex pre-prompt annotation
+@findex prompt annotation
+@findex post-prompt annotation
@item prompt
When @value{GDBN} is prompting for a command (the main @value{GDBN} prompt).
-@findex pre-commands
-@findex commands
-@findex post-commands
+@findex pre-commands annotation
+@findex commands annotation
+@findex post-commands annotation
@item commands
When @value{GDBN} prompts for a set of commands, like in the @code{commands}
command. The annotations are repeated for each command which is input.
-@findex pre-overload-choice
-@findex overload-choice
-@findex post-overload-choice
+@findex pre-overload-choice annotation
+@findex overload-choice annotation
+@findex post-overload-choice annotation
@item overload-choice
When @value{GDBN} wants the user to select between various overloaded functions.
-@findex pre-query
-@findex query
-@findex post-query
+@findex pre-query annotation
+@findex query annotation
+@findex post-query annotation
@item query
When @value{GDBN} wants the user to confirm a potentially dangerous operation.
-@findex pre-prompt-for-continue
-@findex prompt-for-continue
-@findex post-prompt-for-continue
+@findex pre-prompt-for-continue annotation
+@findex prompt-for-continue annotation
+@findex post-prompt-for-continue annotation
@item prompt-for-continue
When @value{GDBN} is asking the user to press return to continue. Note: Don't
expect this to work well; instead use @code{set height 0} to disable
@section Errors
@cindex annotations for errors, warnings and interrupts
-@findex quit
+@findex quit annotation
@smallexample
^Z^Zquit
@end smallexample
This annotation occurs right before @value{GDBN} responds to an interrupt.
-@findex error
+@findex error annotation
@smallexample
^Z^Zerror
@end smallexample
does not necessarily mean that @value{GDBN} is immediately returning all the way
to the top level.
-@findex error-begin
+@findex error-begin annotation
A quit or error annotation may be preceded by
@smallexample
changed.
@table @code
-@findex frames-invalid
+@findex frames-invalid annotation
@item ^Z^Zframes-invalid
The frames (for example, output from the @code{backtrace} command) may
have changed.
-@findex breakpoints-invalid
+@findex breakpoints-invalid annotation
@item ^Z^Zbreakpoints-invalid
The breakpoints may have changed. For example, the user just added or
@section Running the Program
@cindex annotations for running programs
-@findex starting
-@findex stopping
+@findex starting annotation
+@findex stopping annotation
When the program starts executing due to a @value{GDBN} command such as
@code{step} or @code{continue},
annotations describe how the program stopped.
@table @code
-@findex exited
+@findex exited annotation
@item ^Z^Zexited @var{exit-status}
The program exited, and @var{exit-status} is the exit status (zero for
successful exit, otherwise nonzero).
-@findex signalled
-@findex signal-name
-@findex signal-name-end
-@findex signal-string
-@findex signal-string-end
+@findex signalled annotation
+@findex signal-name annotation
+@findex signal-name-end annotation
+@findex signal-string annotation
+@findex signal-string-end annotation
@item ^Z^Zsignalled
The program exited with a signal. After the @code{^Z^Zsignalled}, the
annotation continues:
@var{intro-text}, @var{middle-text}, and @var{end-text} are for the
user's benefit and have no particular format.
-@findex signal
+@findex signal annotation
@item ^Z^Zsignal
The syntax of this annotation is just like @code{signalled}, but @value{GDBN} is
just saying that the program received the signal, not that it was
terminated with it.
-@findex breakpoint
+@findex breakpoint annotation
@item ^Z^Zbreakpoint @var{number}
The program hit breakpoint number @var{number}.
-@findex watchpoint
+@findex watchpoint annotation
@item ^Z^Zwatchpoint @var{number}
The program hit watchpoint number @var{number}.
@end table
@section Displaying Source
@cindex annotations for source display
-@findex source
+@findex source annotation
The following annotation is used instead of displaying source code:
@smallexample
* Interrupts::
* Examples::
* File-I/O remote protocol extension::
+* Memory map format::
@end menu
@node Overview
Reply:
@table @samp
@item @var{XX@dots{}}
-Memory contents; each byte is transmitted as a two-digit hexidecimal
+Memory contents; each byte is transmitted as a two-digit hexadecimal
number. The reply may contain fewer bytes than requested if the
server was able to read only part of the region of memory.
@item E @var{NN}
@cindex @samp{M} packet
Write @var{length} bytes of memory starting at address @var{addr}.
@var{XX@dots{}} is the data; each byte is transmitted as a two-digit
-hexidecimal number.
+hexadecimal number.
Reply:
@table @samp
@anchor{write register packet}
@cindex @samp{P} packet
Write register @var{n@dots{}} with value @var{r@dots{}}. The register
-number @var{n} is in hexidecimal, and @var{r@dots{}} contains two hex
+number @var{n} is in hexadecimal, and @var{r@dots{}} contains two hex
digits for each byte in the register (target byte order).
Reply:
The @samp{vCont} packet is not supported.
@end table
+@item vFlashErase:@var{addr},@var{length}
+@cindex @samp{vFlashErase} packet
+Direct the stub to erase @var{length} bytes of flash starting at
+@var{addr}. The region may enclose any number of flash blocks, but
+its start and end must fall on block boundaries, as indicated by the
+flash block size appearing in the memory map (@pxref{Memory map
+format}). @value{GDBN} groups flash memory programming operations
+together, and sends a @samp{vFlashDone} request after each group; the
+stub is allowed to delay erase operation until the @samp{vFlashDone}
+packet is received.
+
+Reply:
+@table @samp
+@item OK
+for success
+@item E @var{NN}
+for an error
+@end table
+
+@item vFlashWrite:@var{addr}:@var{XX@dots{}}
+@cindex @samp{vFlashWrite} packet
+Direct the stub to write data to flash address @var{addr}. The data
+is passed in binary form using the same encoding as for the @samp{X}
+packet (@pxref{Binary Data}). The memory ranges specified by
+@samp{vFlashWrite} packets preceding a @samp{vFlashDone} packet must
+not overlap, and must appear in order of increasing addresses
+(although @samp{vFlashErase} packets for higher addresses may already
+have been received; the ordering is guaranteed only between
+@samp{vFlashWrite} packets). If a packet writes to an address that was
+neither erased by a preceding @samp{vFlashErase} packet nor by some other
+target-specific method, the results are unpredictable.
+
+
+Reply:
+@table @samp
+@item OK
+for success
+@item E.memtype
+for vFlashWrite addressing non-flash memory
+@item E @var{NN}
+for an error
+@end table
+
+@item vFlashDone
+@cindex @samp{vFlashDone} packet
+Indicate to the stub that flash programming operation is finished.
+The stub is permitted to delay or batch the effects of a group of
+@samp{vFlashErase} and @samp{vFlashWrite} packets until a
+@samp{vFlashDone} packet is received. The contents of the affected
+regions of flash memory are unpredictable until the @samp{vFlashDone}
+request is completed.
+
@item X @var{addr},@var{length}:@var{XX@dots{}}
@anchor{X packet}
@cindex @samp{X} packet
@table @samp
@item S @var{AA}
-The program received signal number @var{AA} (a two-digit hexidecimal
-number).
+The program received signal number @var{AA} (a two-digit hexadecimal
+number). This is equivalent to a @samp{T} response with no
+@var{n}:@var{r} pairs.
@item T @var{AA} @var{n1}:@var{r1};@var{n2}:@var{r2};@dots{}
@cindex @samp{T} packet reply
-The program received signal number @var{AA} (a two-digit hexidecimal
-number). Single-step and breakpoint traps are reported this way. The
-@samp{@var{n}:@var{r}} pairs give the values of important registers or
-other information:
+The program received signal number @var{AA} (a two-digit hexadecimal
+number). This is equivalent to an @samp{S} response, except that the
+@samp{@var{n}:@var{r}} pairs can carry values of important registers
+and other information directly in the stop reply packet, reducing
+round-trip latency. Single-step and breakpoint traps are reported
+this way. Each @samp{@var{n}:@var{r}} pair is interpreted as follows:
@enumerate
@item
-If @var{n} is a hexidecimal number, it is a register number, and the
+If @var{n} is a hexadecimal number, it is a register number, and the
corresponding @var{r} gives that register's value. @var{r} is a
series of bytes in target byte order, with each byte given by a
two-digit hex number.
Reply:
@table @samp
@item QC @var{pid}
-Where @var{pid} is an unsigned hexidecimal process id.
+Where @var{pid} is an unsigned hexadecimal process id.
@item @r{(anything else)}
Any other reply implies the old pid.
@end table
An empty reply indicates that @samp{qGetTLSAddr} is not supported by the stub.
@end table
-Use of this request packet is controlled by the @code{set remote
-get-thread-local-storage-address} command (@pxref{Remote
-configuration, set remote get-thread-local-storage-address}).
-
@item qL @var{startflag} @var{threadcount} @var{nextthread}
Obtain thread information from RTOS. Where: @var{startflag} (one hex
digit) is one to indicate the first query and zero to indicate a
@tab @samp{-}
@tab Yes
+@item @samp{qXfer:memory-map:read}
+@tab No
+@tab @samp{-}
+@tab Yes
+
@end multitable
These are the currently defined stub features, in more detail:
@item qXfer:@var{object}:read:@var{annex}:@var{offset},@var{length}
@cindex read special object, remote request
@cindex @samp{qXfer} packet
+@anchor{qXfer read}
Read uninterpreted bytes from the target's special data area
identified by the keyword @var{object}. Request @var{length} bytes
starting at @var{offset} bytes into the data. The content and
@item qXfer:auxv:read::@var{offset},@var{length}
@anchor{qXfer auxiliary vector read}
Access the target's @dfn{auxiliary vector}. @xref{OS Information,
-auxiliary vector}, and @ref{Remote configuration,
-read-aux-vector-packet}. Note @var{annex} must be empty.
+auxiliary vector}. Note @var{annex} must be empty.
This packet is not probed by default; the remote stub must request it,
by suppling an appropriate @samp{qSupported} response (@pxref{qSupported}).
@end table
+@table @samp
+@item qXfer:memory-map:read::@var{offset},@var{length}
+@anchor{qXfer memory map read}
+Access the target's @dfn{memory-map}. @xref{Memory map format}. The
+annex part of the generic @samp{qXfer} packet must be empty
+(@pxref{qXfer read}).
+
+This packet is not probed by default; the remote stub must request it,
+by supplying an appropriate @samp{qSupported} response (@pxref{qSupported}).
+@end table
+
Reply:
@table @samp
@item m @var{data}
The following @code{g}/@code{G} packets have previously been defined.
In the below, some thirty-two bit registers are transferred as
sixty-four bits. Those registers should be zero/sign extended (which?)
-to fill the space allocated. Register bytes are transfered in target
-byte order. The two nibbles within a register byte are transfered
+to fill the space allocated. Register bytes are transferred in target
+byte order. The two nibbles within a register byte are transferred
most-significant - least-significant.
@table @r
@item MIPS32
-All registers are transfered as thirty-two bit quantities in the order:
+All registers are transferred as thirty-two bit quantities in the order:
32 general-purpose; sr; lo; hi; bad; cause; pc; 32 floating-point
registers; fsr; fir; fp.
@item MIPS64
-All registers are transfered as sixty-four bit quantities (including
+All registers are transferred as sixty-four bit quantities (including
thirty-two bit registers such as @code{sr}). The ordering is the same
as @code{MIPS32}.
@item R @var{mask}
Collect the registers whose bits are set in @var{mask}. @var{mask} is
-a hexidecimal number whose @var{i}'th bit is set if register number
+a hexadecimal number whose @var{i}'th bit is set if register number
@var{i} should be collected. (The least significant bit is numbered
zero.) Note that @var{mask} may be any number of digits long; it may
not fit in a 32-bit word.
number @var{basereg}, plus @var{offset}. If @var{basereg} is
@samp{-1}, then the range has a fixed address: @var{offset} is the
address of the lowest byte to collect. The @var{basereg},
-@var{offset}, and @var{len} parameters are all unsigned hexidecimal
+@var{offset}, and @var{len} parameters are all unsigned hexadecimal
values (the @samp{-1} value for @var{basereg} is a special case).
@item X @var{len},@var{expr}
@table @samp
@item F @var{f}
The selected frame is number @var{n} in the trace frame buffer;
-@var{f} is a hexidecimal number. If @var{f} is @samp{-1}, then there
+@var{f} is a hexadecimal number. If @var{f} is @samp{-1}, then there
was no frame matching the criteria in the request packet.
@item T @var{t}
The selected trace frame records a hit of tracepoint number @var{t};
-@var{t} is a hexidecimal number.
+@var{t} is a hexadecimal number.
@end table
@item QTFrame:pc:@var{addr}
Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the
currently selected frame whose PC is @var{addr};
-@var{addr} is a hexidecimal number.
+@var{addr} is a hexadecimal number.
@item QTFrame:tdp:@var{t}
Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the
currently selected frame that is a hit of tracepoint @var{t}; @var{t}
-is a hexidecimal number.
+is a hexadecimal number.
@item QTFrame:range:@var{start}:@var{end}
Like @samp{QTFrame:@var{n}}, but select the first tracepoint frame after the
currently selected frame whose PC is between @var{start} (inclusive)
-and @var{end} (exclusive); @var{start} and @var{end} are hexidecimal
+and @var{end} (exclusive); @var{start} and @var{end} are hexadecimal
numbers.
@item QTFrame:outside:@var{start}:@var{end}
the target is stopped to allow deterministic access to the target's
memory. Therefore File-I/O is not interruptible by target signals. On
the other hand, it is possible to interrupt File-I/O by a user interrupt
-(Ctrl-C) within @value{GDBN}.
+(@samp{Ctrl-C}) within @value{GDBN}.
The target's request to perform a host system call does not finish
the latest @samp{C}, @samp{c}, @samp{S} or @samp{s} action. That means,
@node The Ctrl-C message
-@subsection The Ctrl-C message
+@subsection The @samp{Ctrl-C} message
@cindex ctrl-c message, in file-i/o protocol
-If the Ctrl-C flag is set in the @value{GDBN}
-reply packet (@pxref{The F reply packet}),
+If the @samp{Ctrl-C} flag is set in the @value{GDBN}
+reply packet (@pxref{The F reply packet}),
the target should behave as if it had
gotten a break message. The meaning for the target is ``system call
interrupted by @code{SIGINT}''. Consequentially, the target should actually stop
(as with a break message) and return to @value{GDBN} with a @code{T02}
-packet.
+packet.
It's important for the target to know in which
state the system call was interrupted. There are two possible cases:
@itemize @bullet
@item
-The user presses @kbd{Ctrl-C}. The behaviour is as explained above, and the
+The user types @kbd{Ctrl-c}. The behaviour is as explained above, and the
@code{read}
system call is treated as finished.
@item
-The user presses @kbd{Enter}. This is treated as end of input with a trailing
+The user presses @key{RET}. This is treated as end of input with a trailing
newline.
@item
-The user presses @kbd{Ctrl-D}. This is treated as end of input. No trailing
-character (neither newline nor Ctrl-D) is appended to the input.
+The user types @kbd{Ctrl-d}. This is treated as end of input. No trailing
+character (neither newline nor @samp{Ctrl-D}) is appended to the input.
@end itemize
-> @code{F-1,9}
@end smallexample
-Example sequence of a read call, user presses Ctrl-C before syscall on
+Example sequence of a read call, user presses @kbd{Ctrl-c} before syscall on
host is called:
@smallexample
<- @code{T02}
@end smallexample
-Example sequence of a read call, user presses Ctrl-C after syscall on
+Example sequence of a read call, user presses @kbd{Ctrl-c} after syscall on
host is called:
@smallexample
<- @code{T02}
@end smallexample
+@node Memory map format
+@section Memory map format
+@cindex memory map format
+
+To be able to write into flash memory, @value{GDBN} needs to obtain a
+memory map from the target. This section describes the format of the
+memory map.
+
+The memory map is obtained using the @samp{qXfer:memory-map:read}
+(@pxref{qXfer memory map read}) packet and is an XML document that
+lists memory regions. The top-level structure of the document is shown below:
+
+@smallexample
+<?xml version="1.0"?>
+<!DOCTYPE memory-map
+ PUBLIC "+//IDN gnu.org//DTD GDB Memory Map V1.0//EN"
+ "http://sourceware.org/gdb/gdb-memory-map.dtd">
+<memory-map>
+ region...
+</memory-map>
+@end smallexample
+
+Each region can be either:
+
+@itemize
+
+@item
+A region of RAM starting at @var{addr} and extending for @var{length}
+bytes from there:
+
+@smallexample
+<memory type="ram" start="@var{addr}" length="@var{length}"/>
+@end smallexample
+
+
+@item
+A region of read-only memory:
+
+@smallexample
+<memory type="rom" start="@var{addr}" length="@var{length}"/>
+@end smallexample
+
+
+@item
+A region of flash memory, with erasure blocks @var{blocksize}
+bytes in length:
+
+@smallexample
+<memory type="flash" start="@var{addr}" length="@var{length}">
+ <property name="blocksize">@var{blocksize}</property>
+</memory>
+@end smallexample
+
+@end itemize
+
+Regions must not overlap. @value{GDBN} assumes that areas of memory not covered
+by the memory map are RAM, and uses the ordinary @samp{M} and @samp{X}
+packets to write to addresses in such ranges.
+
+The formal DTD for memory map format is given below:
+
+@smallexample
+<!-- ................................................... -->
+<!-- Memory Map XML DTD ................................ -->
+<!-- File: memory-map.dtd .............................. -->
+<!-- .................................... .............. -->
+<!-- memory-map.dtd -->
+<!-- memory-map: Root element with versioning -->
+<!ELEMENT memory-map (memory | property)>
+<!ATTLIST memory-map version CDATA #FIXED "1.0.0">
+<!ELEMENT memory (property)>
+<!-- memory: Specifies a memory region,
+ and its type, or device. -->
+<!ATTLIST memory type CDATA #REQUIRED
+ start CDATA #REQUIRED
+ length CDATA #REQUIRED
+ device CDATA #IMPLIED>
+<!-- property: Generic attribute tag -->
+<!ELEMENT property (#PCDATA | property)*>
+<!ATTLIST property name CDATA #REQUIRED>
+@end smallexample
+
@include agentexpr.texi
@include gpl.texi
projects / binutils.git / blobdiff