Changeset 511dc4b in rtems for bsps/powerpc/haleakala/start


Ignore:
Timestamp:
Jun 19, 2018, 7:09:51 AM (2 years ago)
Author:
Sebastian Huber <sebastian.huber@…>
Branches:
master
Children:
9e3bb45
Parents:
715d616
git-author:
Sebastian Huber <sebastian.huber@…> (06/19/18 07:09:51)
git-committer:
Sebastian Huber <sebastian.huber@…> (06/27/18 06:58:16)
Message:

Rework initialization and interrupt stack support

Statically initialize the interrupt stack area
(_Configuration_Interrupt_stack_area_begin,
_Configuration_Interrupt_stack_area_end, and
_Configuration_Interrupt_stack_size) via <rtems/confdefs.h>. Place the
interrupt stack area in a special section ".rtemsstack.interrupt". Let
BSPs define the optimal placement of this section in their linker
command files (e.g. in a fast on-chip memory).

This change makes makes the CPU_HAS_SOFTWARE_INTERRUPT_STACK and
CPU_HAS_HARDWARE_INTERRUPT_STACK CPU port defines superfluous, since the
low level initialization code has all information available via global
symbols.

This change makes the CPU_ALLOCATE_INTERRUPT_STACK CPU port define
superfluous, since the interrupt stacks are allocated by confdefs.h for
all architectures. There is no need for BSP-specific linker command
file magic (except the section placement), see previous ARM linker
command file as a bad example.

Remove _CPU_Install_interrupt_stack(). Initialize the hardware
interrupt stack in _CPU_Initialize() if necessary (e.g.
m68k_install_interrupt_stack()).

The optional _CPU_Interrupt_stack_setup() is still useful to customize
the registration of the interrupt stack area in the per-CPU information.

The initialization stack can reuse the interrupt stack, since

  • interrupts are disabled during the sequential system initialization, and
  • the boot_card() function does not return.

This stack resuse saves memory.

Changes per architecture:

arm:

  • Mostly replace the linker symbol based configuration of stacks with the standard <rtems/confdefs.h> configuration via CONFIGURE_INTERRUPT_STACK_SIZE. The size of the FIQ, ABT and UND mode stack is still defined via linker symbols. These modes are rarely used in applications and the default values provided by the BSP should be sufficient in most cases.
  • Remove the bsp_processor_count linker symbol hack used for the SMP support. This is possible since the interrupt stack area is now allocated by the linker and not allocated from the heap. This makes some configure.ac stuff obsolete. Remove the now superfluous BSP variants altcycv_devkit_smp and realview_pbx_a9_qemu_smp.

bfin:

  • Remove unused magic linker command file allocation of initialization stack. Maybe a previous linker command file copy and paste problem? In the start.S the initialization stack is set to a hard coded value.

lm32, m32c, mips, nios2, riscv, sh, v850:

  • Remove magic linker command file allocation of initialization stack. Reuse interrupt stack for initialization stack.

m68k:

  • Remove magic linker command file allocation of initialization stack. Reuse interrupt stack for initialization stack.

powerpc:

  • Remove magic linker command file allocation of initialization stack. Reuse interrupt stack for initialization stack.
  • Used dedicated memory region (REGION_RTEMSSTACK) for the interrupt stack on BSPs using the shared linkcmds.base (replacement for REGION_RWEXTRA).

sparc:

  • Remove the hard coded initialization stack. Use the interrupt stack for the initialization stack on the boot processor. This saves 16KiB of RAM.

Update #3459.

Location:
bsps/powerpc/haleakala/start
Files:
3 edited

Legend:

Unmodified
Added
Removed
  • bsps/powerpc/haleakala/start/bspstart.c

    r715d616 r511dc4b  
    6767
    6868#include <stdio.h>
    69 
    70 LINKER_SYMBOL(intrStack_start);
    71 LINKER_SYMBOL(intrStack_size);
    7269/*
    7370 *  Driver configuration parameters
     
    189186   */
    190187  ppc_exc_initialize(
    191     (uintptr_t) intrStack_start,
    192     (uintptr_t) intrStack_size
     188    (uintptr_t) _Configuration_Interrupt_stack_area_begin,
     189    rtems_configuration_get_interrupt_stack_size()
    193190  );
    194191
  • bsps/powerpc/haleakala/start/dlentry.S

    r715d616 r511dc4b  
    5555 * see linker command file for section placement
    5656 *
    57  *  The initial stack is set to stack.end
     57 *  The initial stack is set to _Configuration_Interrupt_stack_area_end.
    5858 *
    5959 *  All the entry veneer has to do is to clear the BSS.
     
    9999                .long   sbss.start
    100100stack_top:
    101                 .long   stack.end
     101                .long   _Configuration_Interrupt_stack_area_end
    102102PUBLIC_VAR (text_addr)
    103103text_addr:
  • bsps/powerpc/haleakala/start/linkcmds

    r715d616 r511dc4b  
    1414ENTRY(download_entry)
    1515EXTERN(__vectors)
    16 
    17 kIntrStackSize = 16K;
    18 kMainStackSize = 64K;
    1916
    2017RamBase = DEFINED(RamBase) ? RamBase : 0;
     
    247244    bss.size = bss.end - bss.start;
    248245    sbss.size = sbss.end - sbss.start;
    249                        
    250     /* Interrupt stack: align to a cache-line boundary */
    251     IntrStack_start = ALIGN(0x20);
    252     . += kIntrStackSize;
    253     intrStack = .;
    254     PROVIDE(intrStackPtr = intrStack);
    255     PROVIDE(intrStack_start = IntrStack_start);
    256     PROVIDE(intrStack_size = kIntrStackSize);
    257 
    258         /* Main stack: align to a cache-line boundary */
    259         stack.start = ALIGN(0x20);
    260         . += kMainStackSize;
    261         stack.end   = .;
    262246
    263247    .rtemsstack (NOLOAD) : {
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