lkml.org 
[lkml]   [2017]   [Mar]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2/3] firmware: qcom: scm: Expose download-mode control
On Fri, Mar 17, 2017 at 09:15:22PM -0700, Bjorn Andersson wrote:
> In order to aid post-mortem debugging the Qualcomm platforms provides a
> "memory download mode", where the boot loader will provide an interface
> for custom tools to "download" the content of RAM to a host machine.
>
> The mode is triggered by writing a magic value somehwere in RAM, that is
> read in the boot code path after a warm-restart. Two mechanism for
> setting this magic value are supported in modern platforms; a direct SCM
> call to enable the mode or through a secure io write of a magic value.
>
> In order for a normal reboot not to trigger "download mode" the magic
> must be cleared during a clean reboot.
>
> Download mode has to be enabled by including qcom_scm.download_mode=1 on
> the command line.
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> .../devicetree/bindings/firmware/qcom,scm.txt | 1 +
> drivers/firmware/qcom_scm-32.c | 6 ++++
> drivers/firmware/qcom_scm-64.c | 16 +++++++++
> drivers/firmware/qcom_scm.c | 42 ++++++++++++++++++++++
> drivers/firmware/qcom_scm.h | 2 ++
> 5 files changed, 67 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/firmware/qcom,scm.txt b/Documentation/devicetree/bindings/firmware/qcom,scm.txt
> index 20f26fbce875..8467a181f22c 100644
> --- a/Documentation/devicetree/bindings/firmware/qcom,scm.txt
> +++ b/Documentation/devicetree/bindings/firmware/qcom,scm.txt
> @@ -18,6 +18,7 @@ Required properties:
> * Core, iface, and bus clocks required for "qcom,scm"
> - clock-names: Must contain "core" for the core clock, "iface" for the interface
> clock and "bus" for the bus clock per the requirements of the compatible.
> +- qcom,dload-mode-addr: Specifies the address for the download mode magic (optional)

Size? 1 cell, 2 cell(, red cell, blue cell) or follows #addr-cells?

Rob

\
 
 \ /
  Last update: 2017-03-24 16:07    [W:0.057 / U:0.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site