Stitch Tool

StitchLoader.py is a utility to replace SBL image in a fully flashable IFWI image. It takes all system firmware components from a working IFWI image and replace the BIOS region with SBL components.

This tool is used to create two output files:

IFWI image with SBL (-o option).
SBL BIOS image for capsule update (-b option). See Firmware Update.

The command line options to perform stitching:

usage: StitchLoader.py [-h] -i IFWI_IN [-o IFWI_OUT] [-b BIOS_OUT]
                       [-s STITCH_IN] [-p PLAT_DATA]

optional arguments:
  -h, --help            show this help message and exit
  -i IFWI_IN, --input-ifwi-file IFWI_IN
                        Specify input template IFWI image file path
  -o IFWI_OUT, --output-ifwi-file IFWI_OUT
                        Specify generated output IFWI image file path
  -b BIOS_OUT, --output-bios-region BIOS_OUT
                        Specify generated output BIOS region image file path
  -s STITCH_IN, --sitch-zip-file STITCH_IN
                        Specify input sitching zip package file path
  -p PLAT_DATA, --platform-data PLAT_DATA
                        Specify a platform specific data (HEX, DWORD) for
                        customization

PLAT_DATA is a DWORD containing platform data to configure debug UART port number. Format is defined below:

For Apollo Lake:
  typedef struct {
      UINT8               PlatformId : 5;    /* Platform ID     */
      UINT8               Reserved1  : 3;
      UINT8               DebugUart  : 2;    /* UART port index */
      UINT8               Reserved2  : 6;
      UINT8               Reserved3;
      UINT8               Marker;            /* 'AA'            */
  } STITCH_DATA;

For Coffee Lake Refresh and Whiskey Lake:
  typedef struct {
      UINT8               PlatformId : 5;    /* Platform ID     */
      UINT8               Reserved1  : 3;
      UINT8               DebugUart;         /* UART port index */
      UINT8               Reserved3;
      UINT8               Marker;            /* 'AA'            */
  } STITCH_DATA;

IFWI Image vs. SBL BIOS Image

IFWI image is used as input to program SPI flash on the hardware, while SBL BIOS image is used as input file to create firmware update capsule image.