Imagelibrary/rtems
1
0
Fork 1
mirror of https://gitlab.rtems.org/rtems/rtos/rtems.git synced 2025-12-05 15:15:44 +00:00
Code Issues Packages Projects Releases Wiki Activity

2003-02-20 Till Straumann <strauman@slac.stanford.edu>

Browse Source 
PR 349/bsps
	* startup/pgtbl_setup.c, startup/pgtbl_activate.c: New files
	* startup/Makefile.am, startup/bspstart.c, startup/linkcmds:
	Let the powerpc/shared (+derived) BSPs use pagetable support
   	from libcpu.
This commit is contained in:
Joel Sherrill
2003-02-20 21:45:49 +00:00
parent 422d561d4a
commit 837a1323e3
6 changed files with 205 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

93
c/src/lib/libbsp/powerpc/shared/startup/pgtbl_setup.c Normal file
View File

@@ -0,0 +1,93 @@
/* $Id$ */
#include <rtems.h>
#include <libcpu/mmu.h>
#include <libcpu/page.h>
#include <rtems/bspIo.h>
#include <libcpu/pte121.h>
/* Default setup of the page tables. This is a weak
* alias, so applications may easily override this
* default setup.
*
* NOTE: while it is possible to change the individual
* mappings, the page table itself MUST be
* allocated at the top of the physical memory!
* bspstart.c RELIES on this.
* Also, the 'setup' routine must reduce
* *pmemsize by the size of the page table.
*/
/* Author: Till Straumann, <strauman@slac.stanford.edu>, 4/2002 */
Triv121PgTbl
BSP_pgtbl_setup(unsigned long) __attribute__ (( weak, alias("__BSP_default_pgtbl_setup") ));
Triv121PgTbl
__BSP_default_pgtbl_setup(unsigned int *pmemsize)
{
Triv121PgTbl pt;
unsigned ldPtSize,tmp;
/* Allocate a page table large enough to map
* the entire physical memory. We put the page
* table at the top of the physical memory.
*/
/* get minimal size (log base 2) of PT for
* this board's memory
*/
ldPtSize = triv121PgTblLdMinSize(*pmemsize);
ldPtSize++; /* double this amount -- then why? */
/* allocate the page table at the top of the physical
* memory - THIS IS NOT AN OPTION - bspstart.c RELIES
* ON THIS LAYOUT! (the size, however may be changed)
*/
if ( (pt = triv121PgTblInit(*pmemsize - (1<<ldPtSize), ldPtSize)) ) {
/* get those from the linker script.
* NOTE THAT THE CORRECTNESS OF THE LINKER SCRIPT IS CRUCIAL
*/
extern unsigned long __DATA_START__, _etext;
/* map text and RO data read-only */
tmp = triv121PgTblMap(
pt,
TRIV121_121_VSID,
0,
(PAGE_ALIGN((unsigned long)&_etext) - 0) >> PG_SHIFT,
0, /* WIMG */
TRIV121_PP_RO_PAGE);
if (TRIV121_MAP_SUCCESS != tmp) {
printk("Unable to map page index %i; reverting to BAT0\n",
tmp);
pt = 0;
} else {
/* map the rest (without the page table itself) RW */
tmp = triv121PgTblMap(
pt,
TRIV121_121_VSID,
(unsigned long)&__DATA_START__,
(*pmemsize - (1<<ldPtSize) - (unsigned long)&__DATA_START__ )>> PG_SHIFT,
0, /* WIMG */
TRIV121_PP_RW_PAGE);
if (TRIV121_MAP_SUCCESS != tmp) {
printk("Unable to map page index %i; reverting to BAT0\n",
tmp);
pt = 0;
}
}
} else {
printk("WARNING: unable to allocate page table, keeping DBAT0\n");
}
if (pt) {
#ifdef SHOW_MORE_INIT_SETTINGS
printk("Setting up page table mappings; protecting text/read-only data from write access\n");
#endif
/* SUCCESS; reduce available memory by size of the page table */
*pmemsize -= (1<<ldPtSize);
}
return pt;
}