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| -rw-r--r-- | Documentation/hid/intel-ish-hid.rst | 65 |
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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 ------------- |