Name

HAL Port — Implementation Details

Overview

This documentation explains how the eCos HAL specification has been mapped onto the SAMX70-EK board hardware, and should be read in conjunction with that specification. The SAMX70-EK platform HAL package complements the Cortex-M architectural HAL and the SAM variant HAL. It provides functionality which is specific to the target board.

Startup

For ROM and JTAG startup, the HAL will perform initialization, programming the various internal registers including the PLL, peripheral clocks and pin multiplexing. The details of the early hardware startup may be found in the src/samx70_ek_misc.c in both hal_system_init() and hal_platform_init().

Memory Map

The platform HAL package provides the memory layout information needed to generate the linker script. The key memory areas are as follows:

Internal SRAM
This is located at address 0x20400000 of the memory space, and is 384KiB in size. The eCos VSR table occupies the bottom 256 bytes, with the virtual vector table starting at 0x20000200 and extending to 0x20000300. The top of SRAM is reserved for the MCAN message buffer memory, whose size depends on the MCAN configuration, and below those CYGNUM_HAL_COMMON_INTERRUPTS_STACK_SIZE bytes are reserved for the interrupt stack. The remainder of internal RAM is available for use by applications.
Internal FLASH
This is located at address 0x004000000 of the memory space. This region is 2048KiB in size. ROM applications are by default configured to run from this memory.
On-Chip Peripherals
These are accessible at locations 0x40000000 and 0xE0000000 upwards. Descriptions of the contents can be found in the SAMX70 User Manual.

Linker Scripts

The platform linker scripts define the following symbols:

hal_vsr_table
This defines the location of the VSR table. This is set to 0x20000000 for all startup types, and space for 128 entries is reserved.
hal_virtual_vector_table
This defines the location of the virtual vector table used to communicate between a ROM monitor and an eCos application. This is allocated right after the VSR table, at 0x20400200.
hal_mcan_ram1
This defines the location of the message RAM for MCAN1. It is allocated at the top of SRAM, and its size is specified by the MCAN package if present, or will be zero if it is not.
hal_mcan_ram0
This defines the location of the message RAM for MCAN0. It is allocated just before the RAM for MCAN1, and its size is specified by the MCAN package if present, or will be zero if it is not.
hal_interrupt_stack
This defines the location of the interrupt stack. For all startup types this is allocated to the top of internal SRAM just before the MCAN message RAM.
hal_startup_stack
This defines the location of the startup stack. For all startup types it is initially allocated at the half-way point of the interrupt stack.

Real-time characterization

The tm_basic kernel test gives statistics gathered about the real-time characterization and performance of the kernel. The sample output is shown here for information. The test was built for JTAG startup on a SAMV71-XULT board.

Example 268.1. samv71-XULT Real-time characterization

Configured 
Testing parameters:
   Clock samples:            32
   Threads:                  19
   Thread switches:         128
   Mutexes:                 873
   Mailboxes:               254
   Semaphores:             1528
   Scheduler operations:    128
   Counters:                509
   Flags:                  1018
   Alarms:                  436
   Stack Size:             1088

             Startup, main thrd : stack used   108 size  1536
             Startup : Idlethread stack used    76 size  1280

eCos Kernel Timings
Notes: all times are in microseconds (.000001) unless otherwise stated

Reading the hardware clock takes 0 'ticks' overhead
... this value will be factored out of all other measurements
Clock interrupt took    1.03 microseconds (1 raw clock ticks)

Testing parameters:
   Clock samples:            32
   Threads:                  19
   Thread switches:         128
   Mutexes:                  32
   Mailboxes:                32
   Semaphores:               32
   Scheduler operations:    128
   Counters:                 32
   Flags:                    32
   Alarms:                   32
   Stack Size:             1088


                                 Confidence
     Ave     Min     Max     Var  Ave  Min  Function
  ======  ======  ======  ====== ========== ========
INFO:<Ctrl-C disabled until test completion>
    1.16    1.00    2.00    0.27   84%  84% Create thread
    0.26    0.00    1.00    0.39   73%  73% Yield thread [all suspended]
    0.21    0.00    1.00    0.33   78%  78% Suspend [suspended] thread
    0.32    0.00    1.00    0.43   68%  68% Resume thread
    0.42    0.00    1.00    0.49   57%  57% Set priority
    0.11    0.00    1.00    0.19   89%  89% Get priority
    0.68    0.00    1.00    0.43   68%  31% Kill [suspended] thread
    0.32    0.00    1.00    0.43   68%  68% Yield [no other] thread
    0.42    0.00    1.00    0.49   57%  57% Resume [suspended low prio] thread
    0.32    0.00    1.00    0.43   68%  68% Resume [runnable low prio] thread
    0.42    0.00    1.00    0.49   57%  57% Suspend [runnable] thread
    0.32    0.00    1.00    0.43   68%  68% Yield [only low prio] thread
    0.32    0.00    1.00    0.43   68%  68% Suspend [runnable->not runnable]
    0.68    0.00    1.00    0.43   68%  31% Kill [runnable] thread
    0.63    0.00    1.00    0.47   63%  36% Destroy [dead] thread
    1.37    1.00    2.00    0.47   63%  63% Destroy [runnable] thread
    1.53    1.00    2.00    0.50   52%  47% Resume [high priority] thread
    0.52    0.00    1.00    0.50   51%  48% Thread switch

    0.06    0.00    1.00    0.12   93%  93% Scheduler lock
    0.20    0.00    1.00    0.32   79%  79% Scheduler unlock [0 threads]
    0.21    0.00    1.00    0.33   78%  78% Scheduler unlock [1 suspended]
    0.20    0.00    1.00    0.32   79%  79% Scheduler unlock [many suspended]
    0.22    0.00    1.00    0.34   78%  78% Scheduler unlock [many low prio]

    0.09    0.00    1.00    0.17   90%  90% Init mutex
    0.28    0.00    1.00    0.40   71%  71% Lock [unlocked] mutex
    0.34    0.00    1.00    0.45   65%  65% Unlock [locked] mutex
    0.28    0.00    1.00    0.40   71%  71% Trylock [unlocked] mutex
    0.28    0.00    1.00    0.40   71%  71% Trylock [locked] mutex
    0.06    0.00    1.00    0.12   93%  93% Destroy mutex
    3.00    3.00    3.00    0.00  100% 100% Unlock/Lock mutex

    0.22    0.00    1.00    0.34   78%  78% Create mbox
    0.06    0.00    1.00    0.12   93%  93% Peek [empty] mbox
    0.25    0.00    1.00    0.38   75%  75% Put [first] mbox
    0.09    0.00    1.00    0.17   90%  90% Peek [1 msg] mbox
    0.38    0.00    1.00    0.47   62%  62% Put [second] mbox
    0.06    0.00    1.00    0.12   93%  93% Peek [2 msgs] mbox
    0.38    0.00    1.00    0.47   62%  62% Get [first] mbox
    0.34    0.00    1.00    0.45   65%  65% Get [second] mbox
    0.25    0.00    1.00    0.38   75%  75% Tryput [first] mbox
    0.19    0.00    1.00    0.30   81%  81% Peek item [non-empty] mbox
    0.31    0.00    1.00    0.43   68%  68% Tryget [non-empty] mbox
    0.31    0.00    1.00    0.43   68%  68% Peek item [empty] mbox
    0.25    0.00    1.00    0.38   75%  75% Tryget [empty] mbox
    0.09    0.00    1.00    0.17   90%  90% Waiting to get mbox
    0.00    0.00    0.00    0.00  100% 100% Waiting to put mbox
    0.16    0.00    1.00    0.26   84%  84% Delete mbox
    1.09    1.00    2.00    0.17   90%  90% Put/Get mbox

    0.06    0.00    1.00    0.12   93%  93% Init semaphore
    0.25    0.00    1.00    0.38   75%  75% Post [0] semaphore
    0.25    0.00    1.00    0.38   75%  75% Wait [1] semaphore
    0.22    0.00    1.00    0.34   78%  78% Trywait [0] semaphore
    0.31    0.00    1.00    0.43   68%  68% Trywait [1] semaphore
    0.03    0.00    1.00    0.06   96%  96% Peek semaphore
    0.09    0.00    1.00    0.17   90%  90% Destroy semaphore
    1.75    1.00    2.00    0.38   75%  25% Post/Wait semaphore

    0.16    0.00    1.00    0.26   84%  84% Create counter
    0.09    0.00    1.00    0.17   90%  90% Get counter value
    0.06    0.00    1.00    0.12   93%  93% Set counter value
    0.25    0.00    1.00    0.38   75%  75% Tick counter
    0.13    0.00    1.00    0.22   87%  87% Delete counter

    0.09    0.00    1.00    0.17   90%  90% Init flag
    0.28    0.00    1.00    0.40   71%  71% Destroy flag
    0.19    0.00    1.00    0.30   81%  81% Mask bits in flag
    0.31    0.00    1.00    0.43   68%  68% Set bits in flag [no waiters]
    0.41    0.00    1.00    0.48   59%  59% Wait for flag [AND]
    0.38    0.00    1.00    0.47   62%  62% Wait for flag [OR]
    0.41    0.00    1.00    0.48   59%  59% Wait for flag [AND/CLR]
    0.47    0.00    1.00    0.50   53%  53% Wait for flag [OR/CLR]
    0.09    0.00    1.00    0.17   90%  90% Peek on flag

    0.31    0.00    1.00    0.43   68%  68% Create alarm
    0.44    0.00    1.00    0.49   56%  56% Initialize alarm
    0.25    0.00    1.00    0.38   75%  75% Disable alarm
    0.47    0.00    1.00    0.50   53%  53% Enable alarm
    0.28    0.00    1.00    0.40   71%  71% Delete alarm
    0.50    0.00    1.00    0.50  100%  50% Tick counter [1 alarm]
    1.38    1.00    2.00    0.47   62%  62% Tick counter [many alarms]
    0.53    0.00    1.00    0.50   53%  46% Tick & fire counter [1 alarm]
    7.81    7.00    8.00    0.31   81%  18% Tick & fire counters [>1 together]
    1.59    1.00    2.00    0.48   59%  40% Tick & fire counters [>1 separately]
    1.00    1.00    1.00    0.00  100% 100% Alarm latency [0 threads]
    1.00    1.00    1.00    0.00  100% 100% Alarm latency [2 threads]
    1.00    1.00    1.00    0.00  100% 100% Alarm latency [many threads]
    2.00    2.00    2.00    0.00  100% 100% Alarm -> thread resume latency

     192     168     212                    Worker thread stack used (stack size 1088)
            All done, main thrd : stack used   796 size  1536
            All done : Idlethread stack used   164 size  1280

Timing complete - 27860 ms total

PASS:<Basic timing OK>
EXIT:<done>