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<!DOCTYPE html>
<html>
  <head>
    <title>SoC</title>
  </head>
  <body>

<h1>x86 System on a Chip (SoC) Development</h1>
<p>
  SoC development is best done in parallel with development for a specific
  board.  The combined steps are listed
  <a target="_blank" href="../development.html">here</a>.
  The development steps for the SoC are listed below:
</p>
<ol>
  <li><a target="_blank" href="../fsp1_1.html#RequiredFiles">FSP 1.1</a> required files</li>
  <li>SoC <a href="#RequiredFiles">Required Files</a></li>
  <li><a href="#Descriptor">Start Booting</a></li>
  <li><a href="#EarlyDebug">Early Debug</a></li>
  <li><a href="#Bootblock">Bootblock</a></li>
  <li><a href="#TempRamInit">TempRamInit</a></li>
  <li><a href="#Romstage">Romstage</a>
    <ol type="A">
      <li>Enable <a href="#SerialOutput">Serial Output"</a></li>
      <li>Get the <a href="#PreviousSleepState">Previous Sleep State</a></li>
      <li>Add the <a href="#MemoryInit">MemoryInit</a> Support</li>
    </ol>
  </li>
  <li><a href="#Ramstage">Ramstage</a>
    <ol type="A">
      <li><a href="#DeviceTree">Start Device Tree Processing</a></li>
      <li>Set up the <a href="#MemoryMap">Memory Map"</a></li>
    </ol>
  </li>
  <li><a href="#AcpiTables">ACPI Tables</a></li>
</ol>


<hr>
<h1><a name="RequiredFiles">Required Files</a></h1>
<p>
  Create the directory as src/soc/&lt;Vendor&gt;/&lt;Chip Family&gt;.
</p>

<p>
  The following files are required to build a new SoC:
</p>
<ul>
  <li>Include files
    <ul>
      <li>include/soc/pei_data.h</li>
      <li>include/soc/pm.h</li>
    </ul>
  </li>
  <li>Kconfig - Defines the Kconfig value for the SoC and selects the tool
    chains for the various stages:
    <ul>
      <li>select ARCH_BOOTBLOCK_&lt;Tool Chain&gt;</li>
      <li>select ARCH_RAMSTAGE_&lt;Tool Chain&gt;</li>
      <li>select ARCH_ROMSTAGE_&lt;Tool Chain&gt;</li>
      <li>select ARCH_VERSTAGE_&lt;Tool Chain&gt;</li>
    </ul>
  </li>
  <li>Makefile.inc - Specify the include paths</li>
  <li>memmap.c - Top of usable RAM</li>
</ul>


<hr>
<h1><a name="Descriptor">Start Booting</a></h1>
<p>
  Some SoC parts require additional firmware components in the flash.
  This section describes how to add those pieces.
</p>

<h2>Intel Firmware Descriptor</h2>
<p>
  The Intel Firmware Descriptor (IFD) is located at the base of the flash part.
  The following command overwrites the base of the flash image with the Intel
  Firmware Descriptor:
</p>
<pre><code>dd if=descriptor.bin of=build/coreboot.rom conv=notrunc >/dev/null 2>&1</code></pre>


<h2><a name="MEB">Management Engine Binary</a></h2>
<p>
  Some SoC parts contain and require that the Management Engine (ME) be running
  before it is possible to bring the x86 processor out of reset.  A binary file
  containing the management engine code must be added to the firmware using the
  ifdtool.  The following commands add this binary blob:
</p>
<pre><code>util/ifdtool/ifdtool -i ME:me.bin  build/coreboot.rom
mv build/coreboot.rom.new build/coreboot.rom
</code></pre>


<h2><a name="EarlyDebug">Early Debug</a></h2>
<p>
  Early debugging between the reset vector and the time the serial port is enabled
  is most easily done by writing values to port 0x80.
</p>


<h2>Success</h2>
<p>
  When the reset vector is successfully invoked, port 0x80 will output the following value:
</p>
<ul>
  <li>0x01: <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/include/console/post_codes.h;hb=HEAD#l45">POST_RESET_VECTOR_CORRECT</a>
    - Bootblock successfully executed the
    <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/cpu/x86/16bit/reset16.inc;hb=HEAD#l4">reset vector</a>
    and entered the 16-bit code at
    <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/cpu/x86/16bit/entry16.inc;hb=HEAD#l35">_start</a>
  </li>
</ul>


<hr>
<h1><a name="Bootblock">Bootblock</a></h1>
<p>
  Implement the bootblock using the following steps:
</p>
<ol>
  <li>Create the directory as src/soc/&lt;Vendor&gt;/&lt;Chip Family&gt;/bootblock</li>
  <li>Add the timestamp.inc file which initializes the floating point registers and saves
    the initial timestamp.
  </li>
  <li>Add the bootblock.c file which:
    <ol type="A">
      <li>Enables memory-mapped PCI config access</li>
      <li>Updates the microcode by calling intel_update_microcode_from_cbfs</li>
      <li>Enable ROM caching</li>
    </ol>
  </li>
  <li>Edit the src/soc/&lt;Vendor&gt;/&lt;Chip Family&gt;/Kconfig file
    <ol type="A">
      <li>Add the BOOTBLOCK_CPU_INIT value to point to the bootblock.c file</li>
      <li>Add the CHIPSET_BOOTBLOCK_INCLUDE value to point to the timestamp.inc file</li>
    </ol>
  </li>
  <li>Edit the src/soc/&lt;Vendor&gt;/&lt;Chip Family&gt;/Makefile.inc file
    <ol type="A">
      <li>Add the bootblock subdirectory</li>
    </ol>
  </li>
  <li>Edit the src/soc/&lt;Vendor&gt;/&lt;Chip Family&gt;/memmap.c file
    <ol type="A">
      <li>Add the fsp/memmap.h include file</li>
      <li>Add the mmap_region_granularity routine</li>
    </ol>
  </li>
  <li>Add the necessary .h files to define the necessary values and structures</li>
  <li>When successful port 0x80 will output the following values:
    <ol type="A">
      <li>0x01: <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/include/console/post_codes.h;hb=HEAD#l45">POST_RESET_VECTOR_CORRECT</a>
        - Bootblock successfully executed the
        <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/cpu/x86/16bit/reset16.inc;hb=HEAD#l4">reset vector</a>
        and entered the 16-bit code at
        <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/cpu/x86/16bit/entry16.inc;hb=HEAD#l35">_start</a>
      </li>
      <li>0x10: <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/include/console/post_codes.h;hb=HEAD#l53">POST_ENTER_PROTECTED_MODE</a>
        - Bootblock executing in
        <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/cpu/x86/32bit/entry32.inc;hb=HEAD#l55">32-bit mode</a>
      </li>
      <li>0x10 - Verstage/romstage reached 32-bit mode</li>
    </ol>
  </li>
</ol>

<p>
  <b>Build Note:</b> The following files are included into the default bootblock image:
</p>
<ul>
  <li><a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/arch/x86/bootblock_romcc.S;hb=HEAD">src/arch/x86/bootblock_romcc.S</a>
    added by   <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/arch/x86/Makefile.inc;hb=HEAD#l133">src/arch/x86/Makefile.inc</a>
    and includes the following files:
    <ul>
      <li><a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/arch/x86/prologue.inc">src/arch/x86/prologue.inc</a></li>
      <li><a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/cpu/x86/16bit/reset16.inc">src/cpu/x86/16bit/reset16.inc</a></li>
      <li><a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/cpu/x86/16bit/entry16.inc">src/cpu/x86/16bit/entry16.inc</a></li>
      <li><a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/cpu/x86/32bit/entry32.inc">src/cpu/x86/32bit/entry32.inc</a></li>
      <li>The code in
        <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/arch/x86/bootblock_romcc.S">src/arch/x86/bootblock_romcc.S</a>
        includes src/soc/&lt;Vendor&gt;/&lt;Chip Family&gt;/bootblock/timestamp.inc using the
        CONFIG_CHIPSET_BOOTBLOCK_INCLUDE value set above
      </li>
      <li><a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/cpu/x86/sse_enable.inc">src/cpu/x86/sse_enable.inc</a></li>
      <li>The code in
        <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/arch/x86/Makefile.inc;hb=HEAD#l156">src/arch/x86/Makefile.inc</a>
        invokes the ROMCC tool to convert the following "C" code into assembler as bootblock.inc:
        <ul>
          <li><a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/arch/x86/include/arch/bootblock_romcc.h">src/arch/x86/include/arch/bootblock_romcc.h</a></li>
          <li><a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/cpu/x86/lapic/boot_cpu.c">src/cpu/x86/lapic/boot_cpu.c</a></li>
          <li>The CONFIG_BOOTBLOCK_CPU_INIT value set above typically points to the code in
            src/soc/&lt;Vendor&gt;/&lt;Chip Family&gt;/bootblock/bootblock.c
          </li>
        </ul>
      </li>
    </ul>
  </li>
  <li><a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/arch/x86/id.S">src/arch/x86/id.S</a>
    added by <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/arch/x86/Makefile.inc;hb=HEAD#l110">src/arch/x86/Makefile.inc</a>
  </li>
  <li><a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/cpu/intel/fit/fit.S">src/cpu/intel/fit/fit.S</a>
    added by <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/cpu/intel/fit/Makefile.inc;hb=HEAD">src/cpu/intel/fit/Makefile.inc</a>
  </li>
  <li><a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/arch/x86/walkcbfs.S">src/arch/x86/walkcbfs.S</a>
    added by <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/arch/x86/Makefile.inc;hb=HEAD#l137">src/arch/x86/Makefile.inc</a>
  </li>
</ul>


<hr>
<h1><a name="TempRamInit">TempRamInit</a></h1>
<p>
  Enable the call to TempRamInit in two stages:
</p>
<ol>
  <li>Finding the FSP binary in the read-only CBFS region</li>
  <li>Call TempRamInit</li>
</ol>


<h2>Find FSP Binary</h2>
<p>
Use the following steps to locate the FSP binary:
</p>
<ol>
  <li>Edit the src/soc/&lt;Vendor&gt;/&lt;Chip Family&gt;/Kconfig file
    <ol type="A">
      <li>Add "select USE_GENERIC_FSP_CAR_INC" to enable the use of
        <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/drivers/intel/fsp1_1/cache_as_ram.inc">src/drivers/intel/fsp1_1/cache_as_ram.inc</a>
      </li>
      <li>Add "select SOC_INTEL_COMMON" to enable the use of the files from src/soc/intel/common
        specifically building
        <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/soc/intel/common/util.c">util.c</a>
      </li>
    </ol>
  </li>
  <li>Debug the result until port 0x80 outputs
    <ol type="A">
      <li>0x90: <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/include/console/post_codes.h;hb=HEAD#l205">POST_FSP_TEMP_RAM_INIT</a>
        - Just before calling
        <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/drivers/intel/fsp1_1/cache_as_ram.inc;hb=HEAD#l73">TempRamInit</a>
      </li>
      <li>Alternating 0xba and 0x01 - The FSP image was not found</li>
    </ol>
  </li>
  <li>Add the <a target="_blank" href="../fsp1_1.html#FspBinary">FSP binary file</a> to the flash image</li>
  <li>Set the following Kconfig values:
    <ul>
      <li>CONFIG_FSP_LOC to the FSP base address specified in the previous step</li>
      <li>CONFIG_FSP_IMAGE_ID_STRING</li>
    </ul>
  </li>
  <li>Debug the result until port 0x80 outputs
    <ol type="A">
      <li>0x90: <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/include/console/post_codes.h;hb=HEAD#l205">POST_FSP_TEMP_RAM_INIT</a>
        - Just before calling
        <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/drivers/intel/fsp1_1/cache_as_ram.inc;hb=HEAD#l73">TempRamInit</a>
      </li>
      <li>Alternating 0xbb and 0x02 - TempRamInit executed, no CPU microcode update found</li>
    </ol>
  </li>
</ol>


<h2>Calling TempRamInit</h2>
<p>
Use the following steps to debug the call to TempRamInit:
</p>
<ol>
  <li>Add the CPU microcode update file
    <ol type="A">
      <li>Add the microcode file with the following command
<pre><code>util/cbfstool/cbfstool build/coreboot.rom add -t microcode -n cpu_microcode_blob.bin -b &lt;base address&gt; -f cpu_microcode_blob.bin</code></pre>
      </li>
      <li>Set the Kconfig values
        <ul>
          <li>CONFIG_CPU_MICROCODE_CBFS_LOC set to the value from the previous step</li>
          <li>CONFIG_CPU_MICROCODE_CBFS_LEN</li>
        </ul>
      </li>
    </ol>
  </li>
  <li>Debug the result until port 0x80 outputs
    <ol type="A">
      <li>0x90: <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/include/console/post_codes.h;hb=HEAD#l205">POST_FSP_TEMP_RAM_INIT</a>
        - Just before calling
        <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/drivers/intel/fsp1_1/cache_as_ram.inc;hb=HEAD#l73">TempRamInit</a>
      </li>
      <li>0x2A - Just before calling
        <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/drivers/intel/fsp1_1/cache_as_ram.inc;hb=HEAD#l151">cache_as_ram_main</a>
        which is the start of the verstage code which may be part of romstage
      </li>
    </ol>
  </li>
</ol>


<hr>
<h1><a name="Romstage">Romstage</a></h1>

<h2><a name="SerialOutput">Serial Output</a></h2>
<p>
  The following steps add the serial output support for romstage:
</p>
<ol>
  <li>Create the romstage subdirectory</li>
  <li>Add romstage/romstage.c
    <ol type="A">
      <li>Program the necessary base addresses</li>
      <li>Disable the TCO</li>
    </ol>
  </li>
  <li>Add romstage/Makefile.inc
    <ol type="A">
      <li>Add romstage.c to romstage</li>
    </ol>
  </li>
  <li>Add gpio configuration support if necessary</li>
  <li>Add the necessary .h files to support the build</li>
  <li>Update Makefile.inc
    <ol type="A">
      <li>Add the romstage subdirectory</li>
      <li>Add the gpio configuration support file to romstage</li>
    </ol>
  </li>
  <li>Set the necessary Kconfig values to enable serial output:
    <ul>
      <li>CONFIG_DRIVERS_UART_&lt;driver&gt;=y</li>
      <li>CONFIG_CONSOLE_SERIAL=y</li>
      <li>CONFIG_UART_FOR_CONSOLE=&lt;port&gt;</li>
      <li>CONFIG_CONSOLE_SERIAL_115200=y</li>
    </ul>
  </li>
</ol>


<h2><a name="PreviousSleepState">Determine Previous Sleep State</a></h2>
<p>
  The following steps implement the code to get the previous sleep state:
</p>
<ol>
  <li>Implement the fill_power_state routine which determines the previous sleep state</li>
  <li>Debug the result until port 0x80 outputs
    <ol type="A">
      <li>0x32:
        - Just after entering
        <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/drivers/intel/fsp1_1/romstage.c;hb=HEAD#l99">romstage_common</a>
      </li>
      <li>0x33 - Just after calling
        <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/drivers/intel/fsp1_1/romstage.c;hb=HEAD#l113">soc_pre_ram_init</a>
      </li>
      <li>0x34:
        - Just after entering
        <a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/drivers/intel/fsp1_1/raminit.c;hb=HEAD#l67">raminit</a>
      </li>
    </ol>
</ol>


<h2><a name="MemoryInit">MemoryInit Support</a></h2>
<p>
  The following steps implement the code to support the FSP MemoryInit call:
</p>
<ol>
  <li>Add the chip.h header file to define the UPD values which get passed
    to MemoryInit.  Skip the values containing SPD addresses and DRAM
    configuration data which is determined by the board.
    <p>
      <b>Build Note</b>: The src/mainboard/&lt;Vendor&gt;/&lt;Board&gt;/devicetree.cb
      file specifies the default values for these parameters.  The build
      process creates the static.c module which contains the config data
      structure containing these values.
    </p>
  </li>
  <li>Edit romstage/romstage.c
    <ol type="A">
      <li>Implement the romstage/romstage.c/soc_memory_init_params routine to
        copy the values from the config structure into the UPD structure
      </li>
      <li>Implement the soc_display_memory_init_params routine to display
        the updated UPD parameters by calling fsp_display_upd_value
      </li>
    </ol>
  </li>
</ol>


<hr>
<h1><a name="Ramstage">Ramstage</a></h1>

<h2><a name="DeviceTree">Start Device Tree Processing</a></h2>
<p>
  The src/mainboard/&lt;Vendor&gt;/&lt;Board&gt;/devicetree.cb file drives the
  execution during ramstage.  This file is processed by the util/sconfig utility
  to generate build/mainboard/&lt;Vendor&gt;/&lt;Board&gt;/static.c.  The various
  state routines in
  src/lib/<a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/lib/hardwaremain.c;hb=HEAD#l128">hardwaremain.c</a>
  call dev_* routines which use the tables in static.c to locate operation tables
  associated with the various chips and devices.  After location the operation
  tables, the state routines call one or more functions depending upon the
  state of the state machine.
</p>

<h3><a name="ChipOperations">Chip Operations</a></h3>
<p>
  Kick-starting the ramstage state machine requires creating the operation table
  for the chip listed in devicetree.cb:
</p>
<ol>
  <li>Edit src/soc/&lt;SoC Vendor&gt;/&lt;SoC Family&gt;/chip.c:
    <ol type="A">
      <li>
        This chip's operation table has the name
        soc_&lt;SoC Vendor&gt;_&lt;SoC Family&gt;_ops which is derived from the
        chip path specified in the devicetree.cb file.
      </li>
      <li>Use the CHIP_NAME macro to specify the name for the chip</li>
      <li>For FSP 1.1, specify a .init routine which calls intel_silicon_init</li>
    </ol>
  </li>
  <li>Edit src/soc/&lt;SoC Vendor&gt;/&lt;SoC Family&gt;/Makefile.inc and add chip.c to ramstage</li>
</ol>

<h3>Domain Operations</h3>
<p>
  coreboot uses the domain operation table to initiate operations on all of the
  devices in the domain.  By default coreboot enables all PCI devices which it
  finds.  Listing a device in devicetree.cb gives the board vendor control over
  the device state.  Non-PCI devices may also be listed under PCI device such as
  the LPC bus or SMbus devices.
</p>
<ol>
  <li>Edit src/soc/&lt;SoC Vendor&gt;/&lt;SoC Family&gt;/chip.c:
    <ol type="A">
      <li>
        The domain operation table is typically placed in
        src/soc/&lt;SoC Vendor&gt;/&lt;SoC Family&gt;/chip.c.
        The table typically looks like the following:
<pre><code>static struct device_operations pci_domain_ops = {
	.read_resources	= pci_domain_read_resources,
	.set_resources	= pci_domain_set_resources,
	.scan_bus	= pci_domain_scan_bus,
	.ops_pci_bus	= pci_bus_default_ops,
};
</code></pre>
      </li>
      <li>
        Create a .enable_dev entry in the chip operations table which points to a
        routine which sets the domain table for the device with the DEVICE_PATH_DOMAIN.
<pre><code>	if (dev->path.type == DEVICE_PATH_DOMAIN) {
		dev->ops = &pci_domain_ops;
	}
</code></pre>
      </li>
      <li>
        During the BS_DEV_ENUMERATE state, ramstage now display the device IDs
        for the PCI devices on the bus.
      </li>
    </ol>
  </li>
  <li>Set CONFIG_DEBUG_BOOT_STATE=y in the .config file</li>
  <li>
    Debug the result until the PCI vendor and device IDs are displayed
    during the BS_DEV_ENUMERATE state.
  </li>
</ol>


<h2><a name="DeviceDrivers">PCI Device Drivers</a></h2>
<p>
  PCI device drivers consist of a ".c" file which contains a "pci_driver" data
  structure at the end of the file with the attribute tag "__pci_driver".  This
  attribute tag places an entry into a link time table listing the various
  coreboot device drivers.
</p>
<p>
  Specify the following fields in the table:
</p>
<ol>
  <li>.vendor - PCI vendor ID value of the device</li>
  <li>.device - PCI device ID value of the device or<br>
  .devices - Address of a zero terminated array of PCI device IDs
  </li>
  <li>.ops - Operations table for the device.  This is the address
    of a "static struct device_operations" data structure specifying
    the routines to execute during the different states and sub-states
    of ramstage's processing.
  </li>
  <li>Turn on the device in mainboard/&lt;Vendor&gt;/&lt;Board&gt;/devicetree.cb</li>
  <li>
    Debug until the device is on and properly configured in coreboot and
    usable by the payload
  </li>
</ol>

<h3><a name="SubsystemIds">Subsystem IDs</a></h3>
<p>
  PCI subsystem IDs are assigned during the BS_DEV_ENABLE state.  The device
  driver may use the common mechanism to assign subsystem IDs by adding
  the ".ops_pci" to the pci_driver data structure.  This field points to
  a "struct pci_operations" that specifies a routine to set the subsystem
  IDs for the device.  The routine might look something like this:
</p>
<pre><code>static void pci_set_subsystem(device_t dev, unsigned vendor, unsigned device)
{
	if (!vendor || !device) {
		vendor = pci_read_config32(dev, PCI_VENDOR_ID);
		device = vendor >> 16;
	}
	printk(BIOS_SPEW,
		"PCI: %02x:%02x:%d subsystem vendor: 0x%04x, device: 0x%04x\n",
		0, PCI_SLOT(dev->path.pci.devfn), PCI_FUNC(dev->path.pci.devfn),
		vendor & 0xffff, device);
	pci_write_config32(dev, PCI_SUBSYSTEM_VENDOR_ID,
			((device & 0xffff) << 16) | (vendor & 0xffff));
}
</code></pre>



<h2>Set up the <a name="MemoryMap">Memory Map</a></h2>
<p>
  The memory map is built by the various PCI device drivers during the
  BS_DEV_RESOURCES state of ramstage.  The northcluster driver will typically
  specify the DRAM resources while the other drivers will typically specify
  the IO resources.  These resources are hung off the device_t data structure by
  src/device/device_util.c/<a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/device/device_util.c;hb=HEAD#l448">new_resource</a>.
</p>
<p>
  During the BS_WRITE_TABLES state, coreboot collects these resources and
  places them into a data structure identified by LB_MEM_TABLE.
</p>
<p>
  Edit the device driver file:
</p>
<ol>
  <li>
    Implement a read_resources routine which calls macros defined in
    src/include/device/<a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/include/device/device.h;hb=HEAD#l237">device.h</a>
    like:
    <ul>
      <li>ram_resource</li>
      <li>reserved_ram_resource</li>
      <li>bad_ram_resource</li>
      <li>uma_resource</li>
      <li>mmio_resource</li>
    </ul>
  </li>
</ol>

<p>
  Testing: Verify that the resources are properly displayed by coreboot during the BS_WRITE_TABLES state.
</p>



<hr>
<h1><a name="AcpiTables">ACPI Tables</a></h1>
<p>
  One of the payloads that needs ACPI tables is the EDK2 CorebootPayloadPkg.
</p>

<h2>FADT</h2>
<p>
  The EDK2 module
  CorebootModulePkg/CbSupportPei/<a target="_blank" href="https://github.com/tianocore/edk2/blob/master/CorebootModulePkg/CbSupportPei/CbSupportPei.c#l342">CbSupportPei.c</a>
  requires that the FADT contains the following values:
</p>
<table border="1">
  <tr bgcolor="#c0ffc0">
    <td>EDK2 Field</td>
    <td>Coreboot Field</td>
  </tr>
  <tr><td>Pm1aCntBlk</td><td>pm1a_cnt_blk</td></tr>
  <tr><td>PmTmrBlk</td><td>pm_tmr_blk</td></tr>
  <tr><td>ResetReg.Address</td><td>reset_reg.</td></tr>
  <tr><td>ResetValue</td><td>reset_value</td></tr>
  <tr><td>Pm1aEvtBlk</td><td>pm1a_evt_blk</td></tr>
  <tr><td>Gpe0Blk</td><td>gpe0_blk</td></tr>
  <tr><td>Gpe0BlkLen</td><td>gpe0_blk_len</td></tr>
</table>
<p>
  The EDK2 data structure is defined in
  MdeModulePkg/Include/IndustryStandard/<a target="_blank" href="https://github.com/tianocore/edk2/blob/master/MdePkg/Include/IndustryStandard/Acpi61.h#l111">Acpi61.h</a>
  The coreboot data structure is defined in
  src/arch/x86/include/arch/<a target="_blank" href="http://review.coreboot.org/gitweb?p=coreboot.git;a=blob;f=src/arch/x86/include/arch/acpi.h;hb=HEAD#l237">acpi.h</a>
</p>

<ol>
  <li>
    Select <a target="_blank" href="../Board/board.html#AcpiTables">HAVE_ACPI_TABLES</a>
    in the board's Kconfig file
  </li>
  <li>Create a acpi.c module:
    <ol type="A">
      <li>Add the acpi_fill_in_fadt routine and initialize the values above</li>
    </ol>
  </li>
</ol>


<hr>
<p>Modified: 20 February 2016</p>
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