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| author | Bjorn Andersson | 2017-08-15 00:46:18 +0200 |
|---|---|---|
| committer | Andy Gross | 2017-10-12 06:48:27 +0200 |
| commit | 8c1b7dc9ba2294c6dbd1870a3d2e534bfda3047a (patch) | |
| tree | 8d9823b880adb03cdf422d6773c720b79c6233e5 /drivers/firmware/qcom_scm-64.c | |
| parent | firmware: qcom: scm: Expose secure IO service (diff) | |
| download | kernel-qcow2-linux-8c1b7dc9ba2294c6dbd1870a3d2e534bfda3047a.tar.gz kernel-qcow2-linux-8c1b7dc9ba2294c6dbd1870a3d2e534bfda3047a.tar.xz kernel-qcow2-linux-8c1b7dc9ba2294c6dbd1870a3d2e534bfda3047a.zip | |
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 'drivers/firmware/qcom_scm-64.c')
| -rw-r--r-- | drivers/firmware/qcom_scm-64.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/firmware/qcom_scm-64.c b/drivers/firmware/qcom_scm-64.c index bf50fb59852e..3fea6f563ca9 100644 --- a/drivers/firmware/qcom_scm-64.c +++ b/drivers/firmware/qcom_scm-64.c @@ -440,6 +440,19 @@ int __qcom_scm_iommu_secure_ptbl_init(struct device *dev, u64 addr, u32 size, return ret; } +int __qcom_scm_set_dload_mode(struct device *dev, bool enable) +{ + struct qcom_scm_desc desc = {0}; + struct arm_smccc_res res; + + desc.args[0] = QCOM_SCM_SET_DLOAD_MODE; + desc.args[1] = enable ? QCOM_SCM_SET_DLOAD_MODE : 0; + desc.arginfo = QCOM_SCM_ARGS(2); + + return qcom_scm_call(dev, QCOM_SCM_SVC_BOOT, QCOM_SCM_SET_DLOAD_MODE, + &desc, &res); +} + int __qcom_scm_io_readl(struct device *dev, phys_addr_t addr, unsigned int *val) { |