summaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
authorBjorn Andersson <bjorn.andersson@linaro.org>2017-08-14 15:46:18 -0700
committerAndy Gross <andy.gross@linaro.org>2017-10-11 23:48:27 -0500
commit8c1b7dc9ba2294c6dbd1870a3d2e534bfda3047a (patch)
tree8d9823b880adb03cdf422d6773c720b79c6233e5 /Documentation
parent4e659dbe2d02a56ca0df25c77e099760252a329c (diff)
downloadop-kernel-dev-8c1b7dc9ba2294c6dbd1870a3d2e534bfda3047a.zip
op-kernel-dev-8c1b7dc9ba2294c6dbd1870a3d2e534bfda3047a.tar.gz
firmware: qcom: scm: Expose download-mode control
In order to aid post-mortem debugging the Qualcomm platforms provide 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 somewhere 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. Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Andy Gross <andy.gross@linaro.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/firmware/qcom,scm.txt2
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/firmware/qcom,scm.txt b/Documentation/devicetree/bindings/firmware/qcom,scm.txt
index 20f26fb..7b40054 100644
--- a/Documentation/devicetree/bindings/firmware/qcom,scm.txt
+++ b/Documentation/devicetree/bindings/firmware/qcom,scm.txt
@@ -18,6 +18,8 @@ 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: phandle to the TCSR hardware block and offset of the
+ download mode control register (optional)
Example for MSM8916:
OpenPOWER on IntegriCloud