source: rtems/bsps/lm32/lm32_evr/start/linkcmds @ 511dc4b

5
Last change on this file since 511dc4b was 511dc4b, checked in by Sebastian Huber <sebastian.huber@…>, on 06/19/18 at 07:09:51

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.

  • Property mode set to 100644
File size: 9.9 KB
Line 
1OUTPUT_FORMAT("elf32-lm32", "elf32-lm32",
2              "elf32-lm32")
3OUTPUT_ARCH(lm32)
4ENTRY(start)
5STARTUP(start.o)
6/* Do we need any of these for elf?
7   __DYNAMIC = 0;    */
8
9/*
10 * Declare some sizes. Heap is sized at whatever ram space is left.
11 */
12RamBase = DEFINED(RamBase) ? RamBase : 0x08000000;
13RamSize = DEFINED(RamSize) ? RamSize : 32M;
14HeapSize = DEFINED(HeapSize) ? HeapSize : 2M;
15
16MEMORY {
17        ebr     : ORIGIN = 0x04000000 , LENGTH = 32k
18        sdram   : ORIGIN = 0x08000000 , LENGTH = 32M
19}
20SECTIONS
21{
22  .boot :
23  {
24    KEEP (*(.boot))
25  } > ebr
26
27  /* Read-only sections, merged into text segment: */
28  .interp   : { *(.interp) }    > sdram
29  .hash           : { *(.hash)          }       > sdram
30  .dynsym         : { *(.dynsym)                }       > sdram
31  .dynstr         : { *(.dynstr)                }       > sdram
32  .gnu.version   : { *(.gnu.version)      }     > sdram
33  .gnu.version_d   : { *(.gnu.version_d)  }     > sdram
34  .gnu.version_r   : { *(.gnu.version_r)  }     > sdram
35  .rela.text     :
36    { *(.rela.text) *(.rela.gnu.linkonce.t*) }  > sdram
37  .rela.data     :
38    { *(.rela.data) *(.rela.gnu.linkonce.d*) }  > sdram
39  .rela.rodata   :
40    { *(.rela.rodata*) *(.rela.gnu.linkonce.r*) }       > sdram
41  .rela.got       : { *(.rela.got)      }       > sdram
42  .rela.got1      : { *(.rela.got1)     }       > sdram
43  .rela.got2      : { *(.rela.got2)     }       > sdram
44  .rela.ctors     : { *(.rela.ctors)    }       > sdram
45  .rela.dtors     : { *(.rela.dtors)    }       > sdram
46  .rela.init      : { *(.rela.init)     }       > sdram
47  .rela.fini      : { *(.rela.fini)     }       > sdram
48  .rela.bss       : { *(.rela.bss)      }       > sdram
49  .rela.plt       : { *(.rela.plt)      }       > sdram
50  .rela.sdata     : { *(.rela.sdata)    }       > sdram
51  .rela.sbss      : { *(.rela.sbss)     }       > sdram
52  .rela.sdata2    : { *(.rela.sdata2)   }       > sdram
53  .rela.sbss2     : { *(.rela.sbss2)    }       > sdram
54  .rela.dyn       : { *(.rela.dyn)      }       > sdram
55
56  .init           : { KEEP(*(.init))            } > sdram
57
58  .text      : 
59  {
60    *(.text*)   
61
62    /*
63     * Special FreeBSD sysctl sections.
64     */
65    . = ALIGN (16);
66    __start_set_sysctl_set = .;
67    *(set_sysctl_*);
68    __stop_set_sysctl_set = ABSOLUTE(.);
69    *(set_domain_*);
70    *(set_pseudo_*);
71
72    /* .gnu.warning sections are handled specially by elf32.em.  */
73    *(.gnu.warning)
74    *(.gnu.linkonce.t*)
75  }  > sdram
76
77  .fini           : { _fini = .; KEEP(*(.fini)) } > sdram
78
79  .rodata         : { *(.rodata*) KEEP (*(SORT(.rtemsroset.*))) *(.gnu.linkonce.r*) }   > sdram
80  .rodata1        : { *(.rodata1) }     > sdram
81  .tdata : {
82    _TLS_Data_begin = .;
83    *(.tdata .tdata.* .gnu.linkonce.td.*)
84    _TLS_Data_end = .;
85  } > sdram
86  .tbss : {
87    _TLS_BSS_begin = .;
88    *(.tbss .tbss.* .gnu.linkonce.tb.*) *(.tcommon)
89    _TLS_BSS_end = .;
90  } > sdram
91  _TLS_Data_size = _TLS_Data_end - _TLS_Data_begin;
92  _TLS_Data_begin = _TLS_Data_size != 0 ? _TLS_Data_begin : _TLS_BSS_begin;
93  _TLS_Data_end = _TLS_Data_size != 0 ? _TLS_Data_end : _TLS_BSS_begin;
94  _TLS_BSS_size = _TLS_BSS_end - _TLS_BSS_begin;
95  _TLS_Size = _TLS_BSS_end - _TLS_Data_begin;
96  _TLS_Alignment = MAX (ALIGNOF (.tdata), ALIGNOF (.tbss));
97
98  /* Adjust the address for the data segment.  We want to adjust up to
99     the same address within the page on the next page up.  */
100  . = ALIGN(0x10000) + (. & (0x10000 - 1));
101  /* Ensure the __preinit_array_start label is properly aligned.  We
102     could instead move the label definition inside the section, but
103     the linker would then create the section even if it turns out to
104     be empty, which isn't pretty.  */
105  . = ALIGN(32 / 8);
106  PROVIDE (__preinit_array_start = .);
107  .preinit_array     : { *(.preinit_array) } >sdram
108  PROVIDE (__preinit_array_end = .);
109  PROVIDE (__init_array_start = .);
110  .init_array     : { *(.init_array) } >sdram
111  PROVIDE (__init_array_end = .);
112  PROVIDE (__fini_array_start = .);
113  .fini_array     : { *(.fini_array) } >sdram
114  PROVIDE (__fini_array_end = .);
115
116/* _SDA2_BASE_ = __SDATA2_START__ + 0x8000; */
117  .sdata2         : { *(.sdata2 .sdata2.* .gnu.linkonce.s2.*) } >sdram
118  .sbss2          : { *(.sbss2 .sbss2.* .gnu.linkonce.sb2.*)
119                        /* avoid empty sdata2/sbss2 area -- __eabi would not set up r2
120                         * which may be important if run-time loading is used
121                         */
122                     . += 1;
123                    } >sdram
124  .eh_frame       : { *.(eh_frame)              } >sdram
125
126  /* NOTE: if the BSP uses page tables, the correctness of
127   *       '_etext' (and __DATA_START__) is CRUCIAL - otherwise,
128   *       an invalid mapping may result!!!
129   */
130  _etext = .;
131  PROVIDE (etext = .);
132
133  /* Adjust the address for the data segment.  We want to adjust up to
134     the same address within the page on the next page up.  It would
135     be more correct to do this:
136       . = ALIGN(0x40000) + (ALIGN(8) & (0x40000 - 1));
137     The current expression does not correctly handle the case of a
138     text segment ending precisely at the end of a page; it causes the
139     data segment to skip a page.  The above expression does not have
140     this problem, but it will currently (2/95) cause BFD to allocate
141     a single segment, combining both text and data, for this case.
142     This will prevent the text segment from being shared among
143     multiple executions of the program; I think that is more
144     important than losing a page of the virtual address space (note
145     that no actual memory is lost; the page which is skipped can not
146     be referenced).  */
147  . = ALIGN(0x1000);
148 .data ALIGN(0x1000) :
149  {
150   /* NOTE: if the BSP uses page tables, the correctness of
151    *       '__DATA_START__' (and _etext) is CRUCIAL - otherwise,
152    *       an invalid mapping may result!!!
153    */
154        PROVIDE(__DATA_START__ = ABSOLUTE(.) );
155    *(.data .data.* .gnu.linkonce.d*)   
156    KEEP (*(SORT(.rtemsrwset.*)))
157    SORT(CONSTRUCTORS)
158  } > sdram
159  .data1   : { *(.data1) }      > sdram
160  PROVIDE (__EXCEPT_START__ = .);
161  .gcc_except_table   : {
162    *(.gcc_except_table)
163    *(.gcc_except_table.*)
164  } > sdram
165  PROVIDE (__EXCEPT_END__ = .);
166  .got1           : { *(.got1) }        > sdram
167  /* Put .ctors and .dtors next to the .got2 section, so that the pointers
168     get relocated with -mrelocatable. Also put in the .fixup pointers.
169     The current compiler no longer needs this, but keep it around for 2.7.2  */
170                PROVIDE (_GOT2_START_ = .);
171  .got2           :  { *(.got2) }       > sdram
172  .dynamic        : { *(.dynamic) }     > sdram
173
174  .ctors          :
175  {
176    /* gcc uses crtbegin.o to find the start of
177       the constructors, so we make sure it is
178       first.  Because this is a wildcard, it
179       doesn't matter if the user does not
180       actually link against crtbegin.o; the
181       linker won't look for a file to match a
182       wildcard.  The wildcard also means that it
183       doesn't matter which directory crtbegin.o
184       is in.  */
185    KEEP (*crtbegin.o(.ctors))
186    /* We don't want to include the .ctor section from
187       from the crtend.o file until after the sorted ctors.
188       The .ctor section from the crtend file contains the
189       end of ctors marker and it must be last */
190    KEEP (*(EXCLUDE_FILE (*crtend.o ) .ctors))
191    KEEP (*(SORT(.ctors.*)))
192    KEEP (*(.ctors))
193  } > sdram
194  .dtors          :
195  {
196    KEEP (*crtbegin.o(.dtors))
197    KEEP (*(EXCLUDE_FILE (*crtend.o ) .dtors))
198    KEEP (*(SORT(.dtors.*)))
199    KEEP (*(.dtors))
200  } > sdram
201
202
203                PROVIDE (_FIXUP_START_ = .);
204  .fixup          : { *(.fixup) }       > sdram
205                PROVIDE (_FIXUP_END_ = .);
206                PROVIDE (_GOT2_END_ = .);
207                PROVIDE (_GOT_START_ = .);
208
209  .got            : { *(.got) } > sdram
210  .got.plt        : { *(.got.plt) }     > sdram
211
212                PROVIDE (_GOT_END_ = .);
213
214  .jcr            : { KEEP (*(.jcr)) } > sdram
215
216  /* We want the small data sections together, so single-instruction offsets
217     can access them all, and initialized data all before uninitialized, so
218     we can shorten the on-disk segment size.  */
219/* _SDA_BASE_ = __SDATA_START__ + 0x8000; */
220  .sdata          : { *(.sdata*) *(.gnu.linkonce.s.*)   } >sdram
221  _edata  =  .;
222  _gp = .;
223  PROVIDE (edata = .);
224  .sbss      :
225  {
226    _clear_start = .;
227    PROVIDE (__sbss_start = .);
228    *(.dynsbss)
229    *(.sbss* .gnu.linkonce.sb.*)
230    *(.scommon)
231    /* avoid empty sdata/sbss area -- __eabi would not set up r13
232     * which may be important if run-time loading is used
233     */
234    . += 1;
235    . = ALIGN(16);
236    PROVIDE (__sbss_end = .);
237  } > sdram
238  .plt   : { *(.plt) }  > sdram
239  .bss       :
240  {
241   PROVIDE (__bss_start = .);
242   *(.dynbss)
243   *(.bss .bss* .gnu.linkonce.b*)
244   *(COMMON)
245  . = ALIGN(16);
246  _end = . ;
247  __rtems_end = . ;
248  PROVIDE (end = .);
249
250    . = ALIGN (16);
251    _clear_end = .;
252
253  } > sdram
254
255  .rtemsstack (NOLOAD) : {
256    *(SORT(.rtemsstack.*))
257    WorkAreaBase = .;
258  } > sdram
259
260  /DISCARD/ :
261  {
262    *(.comment)
263  }
264
265
266  /* Stabs debugging sections.  */
267  .stab 0 : { *(.stab) }
268  .stabstr 0 : { *(.stabstr) }
269  .stab.excl 0 : { *(.stab.excl) }
270  .stab.exclstr 0 : { *(.stab.exclstr) }
271  .stab.index 0 : { *(.stab.index) }
272  .stab.indexstr 0 : { *(.stab.indexstr) }
273  .comment 0 : { *(.comment) }
274
275  /* DWARF debug sections.
276     Symbols in the DWARF debugging sections are relative to the beginning
277     of the section so we begin them at 0.  */
278  /* DWARF 1 */
279  .debug          0 : { *(.debug) }
280  .line           0 : { *(.line) }
281 
282  /* GNU DWARF 1 extensions */
283  .debug_srcinfo  0 : { *(.debug_srcinfo) }
284  .debug_sfnames  0 : { *(.debug_sfnames) }
285 
286  /* DWARF 1.1 and DWARF 2 */
287  .debug_aranges  0 : { *(.debug_aranges) }
288  .debug_pubnames 0 : { *(.debug_pubnames) }
289 
290  /* DWARF 2 */
291  .debug_info     0 : { *(.debug_info) }
292  .debug_abbrev   0 : { *(.debug_abbrev) }
293  .debug_line     0 : { *(.debug_line) }
294  .debug_frame    0 : { *(.debug_frame) }
295  .debug_str      0 : { *(.debug_str) }
296  .debug_loc      0 : { *(.debug_loc) }
297  .debug_macinfo  0 : { *(.debug_macinfo) }
298 
299  /* SGI/MIPS DWARF 2 extensions */
300  .debug_weaknames 0 : { *(.debug_weaknames) }
301  .debug_funcnames 0 : { *(.debug_funcnames) }
302  .debug_typenames 0 : { *(.debug_typenames) }
303  .debug_varnames  0 : { *(.debug_varnames) }
304  /* These must appear regardless of  .  */
305}
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