From: Tom Rini <trini@ti.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH v3 5/6] arm: debug: add Kconfig entries for lowlevel debug
Date: Sat, 6 Sep 2014 08:03:17 -0400 [thread overview]
Message-ID: <20140906120317.GP25506@bill-the-cat> (raw)
In-Reply-To: <CAPnjgZ1tLMaQmkLG0fYD-_fdDZzPRfv0zMsMCk3c8RFhTEJ4KA@mail.gmail.com>
On Wed, Sep 03, 2014 at 06:01:44PM -0600, Simon Glass wrote:
> Hi Masahiro,
>
> On 31 August 2014 20:06, Masahiro Yamada <yamada.m@jp.panasonic.com> wrote:
> > We have not had a good method to debug the early boot stage such as
> > lowlevel_init function. I guess developers generally use dedicated
> > debuggers for that, but it is difficult in some cases.
> > (For example, my debugger cannot connect to the ARM processor when
> > it is in the secure state. It sometimes happens when I need to
> > debug the early boot stage on ARM SoCs with secure extension.)
> >
> > The low level debug feature in Linux would be also helpful for U-boot
> > when we are stucking in nasty problems where the console is not
> > available yet.
> >
> > You have to enable CONFIG_DEBUG_LL to use this feature.
> > For now, only 8250-compatible UART devices are supported.
> > You can add a header file under arch/arm/include/debug/ directory
> > to support your UART device if necessary.
> >
> > Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
>
> Is it possible to use the existing drivers for this? It seems
> unfortunate to duplicate the ns16550 driver (if that is what has
> happened).
No, the point of this driver (and the similar ones that exist here and
elsewhere) is to have something small and seperate that we know is not
the cause of the problem.
--
Tom
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next prev parent reply other threads:[~2014-09-06 12:03 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-01 2:06 [U-Boot] [PATCH v3 0/6] Introduce low-level debug for ARM architecture Masahiro Yamada
2014-09-01 2:06 ` [U-Boot] [PATCH v3 1/6] vexpress64: kconfig: consolidate CONFIG_TARGET_VEXPRESS_AEMV8A_SEMI Masahiro Yamada
2014-09-03 20:59 ` Masahiro YAMADA
2014-09-01 2:06 ` [U-Boot] [PATCH v3 2/6] kconfig: armv8: move CONFIG_ARM64 to Kconfig Masahiro Yamada
2014-09-01 2:06 ` [U-Boot] [PATCH v3 3/6] arm: debug: import debug files from Linux 3.16 Masahiro Yamada
2014-09-01 2:06 ` [U-Boot] [PATCH v3 4/6] arm: debug: replace license blocks with SPDX Masahiro Yamada
2014-09-01 2:06 ` [U-Boot] [PATCH v3 5/6] arm: debug: add Kconfig entries for lowlevel debug Masahiro Yamada
2014-09-04 0:01 ` Simon Glass
2014-09-05 2:55 ` Masahiro Yamada
2014-09-05 21:16 ` Simon Glass
2014-09-06 12:03 ` Tom Rini [this message]
2014-09-08 17:31 ` Simon Glass
2014-09-01 2:06 ` [U-Boot] [PATCH v3 6/6] arm: debug: adjust for U-Boot Masahiro Yamada
2014-10-27 0:06 ` [U-Boot] [PATCH v3 0/6] Introduce low-level debug for ARM architecture Albert ARIBAUD
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