You've already forked documentation
mirror of
https://github.com/Dasharo/documentation.git
synced 2026-03-06 15:26:51 -08:00
3d16dd6432
Adds relevant info for SBL performance table that will be added to the Firmware Performance Data Table with the PR noted below. https://github.com/slimbootloader/slimbootloader/pull/1890 Also adds a section on how to obtain performance measurements from the OsLoader shell. Signed-off-by: Atharva Lele <atharva.lele@intel.com>
125 lines
5.7 KiB
ReStructuredText
Executable File
125 lines
5.7 KiB
ReStructuredText
Executable File
Boot Performance
|
|
------------------
|
|
|
|
|SPN| aims to boot very quickly. This is mandatory, for some use cases, e.g., turning on rear-view camera system when a car is started.
|
|
|
|
Boot performance is designed in every stage of |SPN|. There are some trade-offs to be considered when one optimizes the boot time.
|
|
|
|
* Type of boot media (e.g., fast boot media such as eMMC)
|
|
* Security features (signing or hashing algorithms, use of hardware acceleration)
|
|
* Hardware configuration (processor frequency, memory size, device configuration etc)
|
|
* Image size with compression algorithm (e.g. Lz4)
|
|
* Generic features (e.g. splash screen, number of boot options)
|
|
|
|
Measuring Boot Performance
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
|SPN| measures boot performance throughout the execution of the bootloader. Measurements are obtained by capturing timestamp values
|
|
during the execution of the bootloader. Each timestamp is associated with an ID that denotes some event in the boot flow. This data
|
|
is passed through a hand-off block (HOB) denoted by the GUID ``gLoaderPerformanceInfoGuid`` to the payload.
|
|
|
|
.. code-block:: C
|
|
|
|
gLoaderPerformanceInfoGuid = { 0x868204be, 0x23d0, 0x4ff9, { 0xac, 0x34, 0xb9, 0x95, 0xac, 0x04, 0xb1, 0xb9 } }
|
|
|
|
This data can be viewed in the the OsLoader shell using the ``perf`` command. An example output is shown below --
|
|
|
|
.. code-block:: text
|
|
|
|
Shell> perf
|
|
Loader Performance Info
|
|
=======================
|
|
|
|
Id | Time (ms) | Delta (ms) | Description
|
|
------+------------+------------+---------------------------
|
|
1000 | 2 ms | 2 ms | Reset vector
|
|
1010 | 9 ms | 7 ms | Stage1A entry point
|
|
1040 | 11 ms | 2 ms | Board PostTempRamInit hook
|
|
1060 | 16 ms | 5 ms | Stage1A continuation
|
|
1080 | 31 ms | 15 ms | Load Stage1B
|
|
10A0 | 82 ms | 51 ms | Verify Stage1B
|
|
10B0 | 84 ms | 2 ms | Decompress Stage1B
|
|
2000 | 84 ms | 0 ms | Stage1B entry point
|
|
2020 | 197 ms | 113 ms | Board PreMemoryInit hook
|
|
2030 | 229 ms | 32 ms | FSP MemoryInit
|
|
2040 | 266 ms | 37 ms | Board PostMemoryInit hook
|
|
2050 | 276 ms | 10 ms | Board PreTempRamExit hook
|
|
2060 | 281 ms | 5 ms | FSP TempRamExit
|
|
2070 | 281 ms | 0 ms | Board PostTempRamExit hook
|
|
2080 | 283 ms | 2 ms | Load Stage2
|
|
2090 | 285 ms | 2 ms | Copy Stage2 to memory
|
|
20A0 | 361 ms | 76 ms | Verify Stage2
|
|
20B0 | 364 ms | 3 ms | Decompress Stage2
|
|
20C0 | 364 ms | 0 ms | Extend Stage2 hash
|
|
20D0 | 365 ms | 1 ms | Rebase Stage2
|
|
3000 | 370 ms | 5 ms | Stage2 entry point
|
|
3010 | 466 ms | 96 ms | Board PreSiliconInit hook
|
|
3020 | 467 ms | 1 ms | Save NVS data
|
|
3030 | 490 ms | 23 ms | FSP SiliconInit
|
|
3040 | 492 ms | 2 ms | Board PostSiliconInit hook
|
|
3050 | 515 ms | 23 ms | Display splash
|
|
3060 | 520 ms | 5 ms | MP wake up
|
|
3080 | 524 ms | 4 ms | MP init run
|
|
3090 | 526 ms | 2 ms | Board PrePciEnumeration hook
|
|
30A0 | 536 ms | 10 ms | PCI enumeration
|
|
30B0 | 543 ms | 7 ms | Board PostPciEnumeration hook
|
|
30C0 | 545 ms | 2 ms | FSP PostPciEnumeration notify
|
|
30D0 | 561 ms | 16 ms | ACPI init
|
|
30E0 | 564 ms | 3 ms | Board PrePayloadLoading hook
|
|
3100 | 567 ms | 3 ms | Load payload
|
|
3110 | 568 ms | 1 ms | Locate payload
|
|
3120 | 577 ms | 9 ms | Copy payload to memory
|
|
3130 | 675 ms | 98 ms | Verify payload
|
|
3140 | 744 ms | 69 ms | Decompress payload
|
|
3150 | 744 ms | 0 ms | Extend payload hash
|
|
31A0 | 746 ms | 2 ms | Board PostPayloadLoading hook
|
|
31B0 | 749 ms | 3 ms | Decode payload format
|
|
31F0 | 749 ms | 0 ms | End of stage2
|
|
------+------------+------------+---------------------------
|
|
|
|
|
|
This performance data is also printed out to the debug port when OsLoader launches the operating system.
|
|
|
|
FPDT Entry
|
|
~~~~~~~~~~
|
|
|
|
OsLoader obtains the performance data from the performance HOB and adds its own execution times to the data.
|
|
OsLoader will also create and publish the SBL Performance ACPI Table (SBLT). This table is pointed
|
|
to by the Firmware Performance Data Table (FPDT). Refer to ACPI Specification for more details on FPDT.
|
|
|
|
|
|
This image shows the FPDT structure after adding SBLT to the FPDT.
|
|
|
|
.. image:: /images/developer-guides/perf_data_fpdt.png
|
|
:width: 800
|
|
|
|
The SBL Boot Performance data is saved using the following struct:
|
|
|
|
.. code-block:: C
|
|
|
|
typedef struct {
|
|
EFI_ACPI_5_0_FPDT_PERFORMANCE_RECORD_HEADER Header;
|
|
UINT32 Reserved;
|
|
///
|
|
/// Time taken for Stage 1 execution in nanoseconds
|
|
///
|
|
UINT64 Stage1Time;
|
|
///
|
|
/// Time taken for Stage 2 execution in nanoseconds
|
|
///
|
|
UINT64 Stage2Time;
|
|
///
|
|
/// Time taken for OsLoader execution in nanoseconds
|
|
///
|
|
UINT64 OsLoaderTime;
|
|
|
|
} SBL_PERFORMANCE_RECORD;
|
|
|
|
The SBL Boot Performance Data can then be accessed via ACPI. It is denoted by the Signature ``SBLT``.
|
|
|
|
.. code-block:: text
|
|
|
|
SBLT @ 0x00000000452B88CC
|
|
0000: 53 42 4C 54 28 00 00 00 00 30 20 01 00 00 00 00 SBLT(....0 .....
|
|
0010: 83 04 00 00 00 00 00 00 B9 0A 00 00 00 00 00 00 ................
|
|
0020: 82 9E 00 00 00 00 00 00 ........ |