| Message ID | 20181008101642.8040-1-jerome.forissier@linaro.org |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | [v2] Documentation: dt: Add binding for /secure-chosen/stdout-path | expand |
On Mon, Oct 08, 2018 at 06:16:42PM +0800, Jerome Forissier wrote: > Some platforms may use a single device tree to describe two address > spaces, as described in d9f43babb998 ("Documentation: dt: Add bindings > for Secure-only devices"). For these platforms it makes sense to define > a secure counterpart of /chosen, namely: /secure-chosen. This new node > is meant to be used by the secure firmware to pass data to the secure > OS. Only the stdout-path property is supported for now. > > Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org> > --- > > Notes: > Sending this again, slightly modified. Previous submission was in March > 2017 [1]. Since then, OP-TEE has implemented this binding for platforms > that use DT [2] (fallback to /chosen/stdout-path to be implemented in > [3]). A patch for QEMU has been proposed [4], to which the maintainer > responded "Are the DT bindings upstream yet?" ;-) > > [1] https://patchwork.kernel.org/patch/9602401/ > [2] https://github.com/OP-TEE/optee_os/commit/4dc31c52544a > [3] https://github.com/OP-TEE/optee_os/pull/2569 > [4] https://patchwork.ozlabs.org/patch/979345/ > > Changes since v1: > - Use "should" instead of "may" ("...the Secure OS should use the value > of /chosen/stdout-path..."). > > Documentation/devicetree/bindings/arm/secure.txt | 19 ++++++++++++++++++- > 1 file changed, 18 insertions(+), 1 deletion(-) Applied. Rob
diff --git a/Documentation/devicetree/bindings/arm/secure.txt b/Documentation/devicetree/bindings/arm/secure.txt index e31303fb233a..f27bbff2c780 100644 --- a/Documentation/devicetree/bindings/arm/secure.txt +++ b/Documentation/devicetree/bindings/arm/secure.txt @@ -32,7 +32,8 @@ describe the view of Secure world using the standard bindings. These secure- bindings only need to be used where both the Secure and Normal world views need to be described in a single device tree. -Valid Secure world properties: +Valid Secure world properties +----------------------------- - secure-status : specifies whether the device is present and usable in the secure world. The combination of this with "status" allows @@ -51,3 +52,19 @@ Valid Secure world properties: status = "disabled"; secure-status = "okay"; /* S-only */ status = "disabled"; /* disabled in both */ status = "disabled"; secure-status = "disabled"; /* disabled in both */ + +The secure-chosen node +---------------------- + +Similar to the /chosen node which serves as a place for passing data +between firmware and the operating system, the /secure-chosen node may +be used to pass data to the Secure OS. Only the properties defined +below may appear in the /secure-chosen node. + +- stdout-path : specifies the device to be used by the Secure OS for + its console output. The syntax is the same as for /chosen/stdout-path. + If the /secure-chosen node exists but the stdout-path property is not + present, the Secure OS should not perform any console output. If + /secure-chosen does not exist, the Secure OS should use the value of + /chosen/stdout-path instead (that is, use the same device as the + Normal world OS).
Some platforms may use a single device tree to describe two address spaces, as described in d9f43babb998 ("Documentation: dt: Add bindings for Secure-only devices"). For these platforms it makes sense to define a secure counterpart of /chosen, namely: /secure-chosen. This new node is meant to be used by the secure firmware to pass data to the secure OS. Only the stdout-path property is supported for now. Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org> --- Notes: Sending this again, slightly modified. Previous submission was in March 2017 [1]. Since then, OP-TEE has implemented this binding for platforms that use DT [2] (fallback to /chosen/stdout-path to be implemented in [3]). A patch for QEMU has been proposed [4], to which the maintainer responded "Are the DT bindings upstream yet?" ;-) [1] https://patchwork.kernel.org/patch/9602401/ [2] https://github.com/OP-TEE/optee_os/commit/4dc31c52544a [3] https://github.com/OP-TEE/optee_os/pull/2569 [4] https://patchwork.ozlabs.org/patch/979345/ Changes since v1: - Use "should" instead of "may" ("...the Secure OS should use the value of /chosen/stdout-path..."). Documentation/devicetree/bindings/arm/secure.txt | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-)