From: Qianru Huang <qianru.huang@xxxxxxxxx>
Add a section to describe the ISH firmware loading process for Lunar Lake
and later generations.
Signed-off-by: Qianru Huang <qianru.huang@xxxxxxxxx>
Signed-off-by: Zhang Lixu <lixu.zhang@xxxxxxxxx>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
---
Documentation/hid/intel-ish-hid.rst | 65 +++++++++++++++++++++++++++++
1 file changed, 65 insertions(+)
diff --git a/Documentation/hid/intel-ish-hid.rst b/Documentation/hid/intel-ish-hid.rst
index 12613cb2be43..55cbaa719a79 100644
--- a/Documentation/hid/intel-ish-hid.rst
+++ b/Documentation/hid/intel-ish-hid.rst
@@ -339,6 +339,71 @@ End to End HID transport Sequence Diagram
| | | |
+ISH Firmware Loading from Host Flow
+-----------------------------------
+
+Starting from the Lunar Lake generation, the ISH firmware has been divided into two components for better space optimization and increased flexibility. These components include a bootloader that is integrated into the BIOS, and a main firmware that is stored within the operating system's file system.
+
+The process works as follows:
+
+- Initially, the ISHTP driver sends a command, HOST_START_REQ_CMD, to the ISH bootloader. In response, the bootloader sends back a HOST_START_RES_CMD. This response includes the ISHTP_SUPPORT_CAP_LOADER bit. Subsequently, the ISHTP driver checks if this bit is set. If it is, the firmware loading process from the host begins.
+
+- During this process, the ISHTP driver first invokes the request_firmware() function, followed by sending a LOADER_CMD_XFER_QUERY command. Upon receiving a response from the bootloader, the ISHTP driver sends a LOADER_CMD_XFER_FRAGMENT command. After receiving another response, the ISHTP driver sends a LOADER_CMD_START command. The bootloader responds and then proceeds to the Main Firmware.
+
+- After the process concludes, the ISHTP driver calls the release_firmware() function.
+
+For more detailed information, please refer to the flow descriptions provided below:
+
+::
+
+ +---------------+ +-----------------+
+ | ISHTP Driver | | ISH Bootloader |
+ +---------------+ +-----------------+
+ | |
+ |~~~Send HOST_START_REQ_CMD~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|
+ | |
+ |<--Send HOST_START_RES_CMD(Includes ISHTP_SUPPORT_CAP_LOADER bit)----|
+ | |
+ ****************************************************************************************
+ * if ISHTP_SUPPORT_CAP_LOADER bit is set *
+ ****************************************************************************************
+ | |
+ |~~~start loading firmware from host process~~~+ |
+ | | |
+ |<---------------------------------------------+ |
+ | |
+ --------------------------- |
+ | Call request_firmware() | |
+ --------------------------- |
+ | |
+ |~~~Send LOADER_CMD_XFER_QUERY~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|
+ | |
+ |<--Send response-----------------------------------------------------|
+ | |
+ |~~~Send LOADER_CMD_XFER_FRAGMENT~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|
+ | |
+ |<--Send response-----------------------------------------------------|
+ | |
+ |~~~Send LOADER_CMD_START~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|
+ | |
+ |<--Send response-----------------------------------------------------|
+ | |
+ | |~~~Jump to Main Firmware~~~+
+ | | |
+ | |<--------------------------+
+ | |
+ --------------------------- |
+ | Call release_firmware() | |
+ --------------------------- |
+ | |
+ ****************************************************************************************
+ * end if *
+ ****************************************************************************************
+ | |
+ +---------------+ +-----------------+
+ | ISHTP Driver | | ISH Bootloader |
+ +---------------+ +-----------------+
+
ISH Debugging
-------------
--
2.34.1
