diff options
Diffstat (limited to 'gdb/doc/gdb.texinfo')
| -rw-r--r-- | gdb/doc/gdb.texinfo | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index bd20b39..5a83619 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -6952,10 +6952,73 @@ and to read-write memory. Beware that the accessed memory corresponds to the live target and not necessarily to the current replay position. +@item set record btrace cpu @var{identifier} +Set the processor to be used for enabling workarounds for processor +errata when decoding the trace. + +Processor errata are defects in processor operation, caused by its +design or manufacture. They can cause a trace not to match the +specification. This, in turn, may cause trace decode to fail. +@value{GDBN} can detect erroneous trace packets and correct them, thus +avoiding the decoding failures. These corrections are known as +@dfn{errata workarounds}, and are enabled based on the processor on +which the trace was recorded. + +By default, @value{GDBN} attempts to detect the processor +automatically, and apply the necessary workarounds for it. However, +you may need to specify the processor if @value{GDBN} does not yet +support it. This command allows you to do that, and also allows to +disable the workarounds. + +The argument @var{identifier} identifies the @sc{cpu} and is of the +form: @code{@var{vendor}:@var{procesor identifier}}. In addition, +there are two special identifiers, @code{none} and @code{auto} +(default). + +The following vendor identifiers and corresponding processor +identifiers are currently supported: + +@multitable @columnfractions .1 .9 + +@item @code{intel} +@tab @var{family}/@var{model}[/@var{stepping}] + +@end multitable + +On GNU/Linux systems, the processor @var{family}, @var{model}, and +@var{stepping} can be obtained from @code{/proc/cpuinfo}. + +If @var{identifier} is @code{auto}, enable errata workarounds for the +processor on which the trace was recorded. If @var{identifier} is +@code{none}, errata workarounds are disabled. + +For example, when using an old @value{GDBN} on a new system, decode +may fail because @value{GDBN} does not support the new processor. It +often suffices to specify an older processor that @value{GDBN} +supports. + +@smallexample +(gdb) info record +Active record target: record-btrace +Recording format: Intel Processor Trace. +Buffer size: 16kB. +Failed to configure the Intel Processor Trace decoder: unknown cpu. +(gdb) set record btrace cpu intel:6/158 +(gdb) info record +Active record target: record-btrace +Recording format: Intel Processor Trace. +Buffer size: 16kB. +Recorded 84872 instructions in 3189 functions (0 gaps) for thread 1 (...). +@end smallexample + @kindex show record btrace @item show record btrace replay-memory-access Show the current setting of @code{replay-memory-access}. +@item show record btrace cpu +Show the processor to be used for enabling trace decode errata +workarounds. + @kindex set record btrace bts @item set record btrace bts buffer-size @var{size} @itemx set record btrace bts buffer-size unlimited |