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>
diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
index a60e4b9..83f171c 100644
--- a/drivers/firmware/qcom_scm.h
+++ b/drivers/firmware/qcom_scm.h
@@ -14,9 +14,11 @@
#define QCOM_SCM_SVC_BOOT 0x1
#define QCOM_SCM_BOOT_ADDR 0x1
+#define QCOM_SCM_SET_DLOAD_MODE 0x10
#define QCOM_SCM_BOOT_ADDR_MC 0x11
#define QCOM_SCM_SET_REMOTE_STATE 0xa
extern int __qcom_scm_set_remote_state(struct device *dev, u32 state, u32 id);
+extern int __qcom_scm_set_dload_mode(struct device *dev, bool enable);
#define QCOM_SCM_FLAG_HLOS 0x01
#define QCOM_SCM_FLAG_COLDBOOT_MC 0x02