cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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dcdbas.rst (3984B)


      1===================================
      2Dell Systems Management Base Driver
      3===================================
      4
      5Overview
      6========
      7
      8The Dell Systems Management Base Driver provides a sysfs interface for
      9systems management software such as Dell OpenManage to perform system
     10management interrupts and host control actions (system power cycle or
     11power off after OS shutdown) on certain Dell systems.
     12
     13Dell OpenManage requires this driver on the following Dell PowerEdge systems:
     14300, 1300, 1400, 400SC, 500SC, 1500SC, 1550, 600SC, 1600SC, 650, 1655MC,
     15700, and 750.  Other Dell software such as the open source libsmbios project
     16is expected to make use of this driver, and it may include the use of this
     17driver on other Dell systems.
     18
     19The Dell libsmbios project aims towards providing access to as much BIOS
     20information as possible.  See http://linux.dell.com/libsmbios/main/ for
     21more information about the libsmbios project.
     22
     23
     24System Management Interrupt
     25===========================
     26
     27On some Dell systems, systems management software must access certain
     28management information via a system management interrupt (SMI).  The SMI data
     29buffer must reside in 32-bit address space, and the physical address of the
     30buffer is required for the SMI.  The driver maintains the memory required for
     31the SMI and provides a way for the application to generate the SMI.
     32The driver creates the following sysfs entries for systems management
     33software to perform these system management interrupts::
     34
     35	/sys/devices/platform/dcdbas/smi_data
     36	/sys/devices/platform/dcdbas/smi_data_buf_phys_addr
     37	/sys/devices/platform/dcdbas/smi_data_buf_size
     38	/sys/devices/platform/dcdbas/smi_request
     39
     40Systems management software must perform the following steps to execute
     41a SMI using this driver:
     42
     431) Lock smi_data.
     442) Write system management command to smi_data.
     453) Write "1" to smi_request to generate a calling interface SMI or
     46   "2" to generate a raw SMI.
     474) Read system management command response from smi_data.
     485) Unlock smi_data.
     49
     50
     51Host Control Action
     52===================
     53
     54Dell OpenManage supports a host control feature that allows the administrator
     55to perform a power cycle or power off of the system after the OS has finished
     56shutting down.  On some Dell systems, this host control feature requires that
     57a driver perform a SMI after the OS has finished shutting down.
     58
     59The driver creates the following sysfs entries for systems management software
     60to schedule the driver to perform a power cycle or power off host control
     61action after the system has finished shutting down:
     62
     63/sys/devices/platform/dcdbas/host_control_action
     64/sys/devices/platform/dcdbas/host_control_smi_type
     65/sys/devices/platform/dcdbas/host_control_on_shutdown
     66
     67Dell OpenManage performs the following steps to execute a power cycle or
     68power off host control action using this driver:
     69
     701) Write host control action to be performed to host_control_action.
     712) Write type of SMI that driver needs to perform to host_control_smi_type.
     723) Write "1" to host_control_on_shutdown to enable host control action.
     734) Initiate OS shutdown.
     74   (Driver will perform host control SMI when it is notified that the OS
     75   has finished shutting down.)
     76
     77
     78Host Control SMI Type
     79=====================
     80
     81The following table shows the value to write to host_control_smi_type to
     82perform a power cycle or power off host control action:
     83
     84=================== =====================
     85PowerEdge System    Host Control SMI Type
     86=================== =====================
     87      300             HC_SMITYPE_TYPE1
     88     1300             HC_SMITYPE_TYPE1
     89     1400             HC_SMITYPE_TYPE2
     90      500SC           HC_SMITYPE_TYPE2
     91     1500SC           HC_SMITYPE_TYPE2
     92     1550             HC_SMITYPE_TYPE2
     93      600SC           HC_SMITYPE_TYPE2
     94     1600SC           HC_SMITYPE_TYPE2
     95      650             HC_SMITYPE_TYPE2
     96     1655MC           HC_SMITYPE_TYPE2
     97      700             HC_SMITYPE_TYPE3
     98      750             HC_SMITYPE_TYPE3
     99=================== =====================