From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Rini Date: Wed, 26 Jun 2013 16:24:35 -0400 Subject: [U-Boot] [PATCH v2 0/21] Add tracing functionality to U-Boot In-Reply-To: <1370974493-21822-1-git-send-email-sjg@chromium.org> References: <1370974493-21822-1-git-send-email-sjg@chromium.org> Message-ID: <20130626202435.GN28078@bill-the-cat> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Tue, Jun 11, 2013 at 11:14:32AM -0700, Simon Glass wrote: > This series adds a tracing feature to U-Boot which is useful for > profiling boot time and other purposes. > > The core trace library relies on standard gcc function instrumentation > and a microsecond timer which should work correctly on almost any > architecture. Generic board is used to avoid the need to add the same > code in multiple places (CONFIG_SYS_GENERIC_BOARD). > > Tracing must be built into the U-Boot image at build time, but can be > paused and resumed while running. A trace buffer is used to collect > trace information. This buffer can then be transmitted to a host for > processing. A host-based processing tool is provided which converts the > data to the same format used by Linux, and that can be read by the > pytimechart GUI tool. > > A U-Boot 'trace' command provides access to the trace information, > including support for writing it to memory in a few forms. > > Support is provided for stopping tracing at the last possible moment in > the bootm process (just before U-Boot jumps to the OS). This is done with > a new 'fake go' command, which allows bootm to go through the motions of > an OS boot without actually committing to it. Once the 'fake go' is > complete, U-Boot can stop tracing and continue execution to transmit the > trace information to the host, before jumping to the OS for real. > > The system is tested on sandbox, x86 and smdk5250/snow. It may work > correctly on Tegra and other machines but unfortunately has not been > tested. A simple test script is provided for sandbox, along with > documentation on how to use the feature. > > This feature has been successfully used alongside bootstage to locate > bottlenecks and reduce overall boot time. With v3 of 17/21, applied to u-boot/master, thanks! -- Tom -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: