From 8c1b7dc9ba2294c6dbd1870a3d2e534bfda3047a Mon Sep 17 00:00:00 2001 From: Bjorn Andersson Date: Mon, 14 Aug 2017 15:46:18 -0700 Subject: 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 Signed-off-by: Bjorn Andersson Signed-off-by: Andy Gross --- drivers/firmware/Kconfig | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'drivers/firmware/Kconfig') diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig index 6e4ed5a9c6fd..fa87a055905e 100644 --- a/drivers/firmware/Kconfig +++ b/drivers/firmware/Kconfig @@ -215,6 +215,17 @@ config QCOM_SCM_64 def_bool y depends on QCOM_SCM && ARM64 +config QCOM_SCM_DOWNLOAD_MODE_DEFAULT + bool "Qualcomm download mode enabled by default" + depends on QCOM_SCM + help + A device with "download mode" enabled will upon an unexpected + warm-restart enter a special debug mode that allows the user to + "download" memory content over USB for offline postmortem analysis. + The feature can be enabled/disabled on the kernel command line. + + Say Y here to enable "download mode" by default. + config TI_SCI_PROTOCOL tristate "TI System Control Interface (TISCI) Message Protocol" depends on TI_MESSAGE_MANAGER -- cgit v1.2.3