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2ae52c7583
PR 356/bsps This patch makes RTEMS/powerpc/shared EABI compliant. * irq/irq_init.c, start/Makefile.am, start/start.S, startup/bspstart.c, startup/pgtbl_setup.c, vectors/vectors.h, vectors/vectors_init.c: zero_bss() should clear not only bss but sbss and sbss2 also (this is probably a bugfix, as sbss/sbss2 are probably used even if -msdata=eabi is not specified). * start/rtems_crti.S: New file which must be linked immediately after ecrti.o. rtems_crti.o contains a code snippet who lets __init() return immediately. Also, a new entry point '_init' to the C++ Ctors is generated for use by the RTEMS Thread_Handler.
94 lines
2.6 KiB
C
94 lines
2.6 KiB
C
/* $Id$ */
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#include <rtems.h>
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#include <libcpu/mmu.h>
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#include <libcpu/page.h>
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#include <rtems/bspIo.h>
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#include <libcpu/pte121.h>
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/* Default setup of the page tables. This is a weak
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* alias, so applications may easily override this
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* default setup.
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*
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* NOTE: while it is possible to change the individual
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* mappings, the page table itself MUST be
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* allocated at the top of the physical memory!
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* bspstart.c RELIES on this.
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* Also, the 'setup' routine must reduce
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* *pmemsize by the size of the page table.
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*/
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/* Author: Till Straumann, <strauman@slac.stanford.edu>, 4/2002 */
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Triv121PgTbl
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BSP_pgtbl_setup(unsigned long) __attribute__ (( weak, alias("__BSP_default_pgtbl_setup") ));
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Triv121PgTbl
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__BSP_default_pgtbl_setup(unsigned int *pmemsize)
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{
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Triv121PgTbl pt;
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unsigned ldPtSize,tmp;
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/* Allocate a page table large enough to map
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* the entire physical memory. We put the page
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* table at the top of the physical memory.
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*/
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/* get minimal size (log base 2) of PT for
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* this board's memory
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*/
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ldPtSize = triv121PgTblLdMinSize(*pmemsize);
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ldPtSize++; /* double this amount -- then why? */
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/* allocate the page table at the top of the physical
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* memory - THIS IS NOT AN OPTION - bspstart.c RELIES
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* ON THIS LAYOUT! (the size, however may be changed)
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*/
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if ( (pt = triv121PgTblInit(*pmemsize - (1<<ldPtSize), ldPtSize)) ) {
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/* get those from the linker script.
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* NOTE THAT THE CORRECTNESS OF THE LINKER SCRIPT IS CRUCIAL
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*/
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extern unsigned long __DATA_START__[], _etext[];
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/* map text and RO data read-only */
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tmp = triv121PgTblMap(
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pt,
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TRIV121_121_VSID,
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0,
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(PAGE_ALIGN((unsigned long)_etext) - 0) >> PG_SHIFT,
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0, /* WIMG */
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TRIV121_PP_RO_PAGE);
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if (TRIV121_MAP_SUCCESS != tmp) {
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printk("Unable to map page index %i; reverting to BAT0\n",
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tmp);
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pt = 0;
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} else {
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/* map the rest (without the page table itself) RW */
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tmp = triv121PgTblMap(
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pt,
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TRIV121_121_VSID,
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(unsigned long)__DATA_START__,
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(*pmemsize - (1<<ldPtSize) - (unsigned long)__DATA_START__ )>> PG_SHIFT,
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0, /* WIMG */
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TRIV121_PP_RW_PAGE);
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if (TRIV121_MAP_SUCCESS != tmp) {
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printk("Unable to map page index %i; reverting to BAT0\n",
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tmp);
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pt = 0;
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}
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}
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} else {
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printk("WARNING: unable to allocate page table, keeping DBAT0\n");
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}
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if (pt) {
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#ifdef SHOW_MORE_INIT_SETTINGS
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printk("Setting up page table mappings; protecting text/read-only data from write access\n");
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#endif
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/* SUCCESS; reduce available memory by size of the page table */
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*pmemsize -= (1<<ldPtSize);
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}
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return pt;
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}
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