2006-05-08 Thomas Schwinge <tschwinge@gnu.org>

* DEVELOPMENT: Document Samuel's patch.

2006-05-08  Samuel Thibault  <samuel.thibault@ens-lyon.org>

	* i386/i386at/model_dep.c (mem_size_init): Limit memory to what can
	actually be used (minus a little extra for virtual mappings).

	* i386/intel/pmap.c (pmap_bootstrap): Extend the virtual mapping area
	according to memory size for at least being able to manage it.  But
	look out for wrap and limit it to kernel adresses.  Remove duplicate
	computing.

4 files changed, 35 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index d9e2617..0deaa8d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2006-05-08  Thomas Schwinge  <tschwinge@gnu.org>
+
+	* DEVELOPMENT: Document Samuel's patch.
+
+2006-05-08  Samuel Thibault  <samuel.thibault@ens-lyon.org>
+
+	* i386/i386at/model_dep.c (mem_size_init): Limit memory to what can
+	actually be used (minus a little extra for virtual mappings).
+
+	* i386/intel/pmap.c (pmap_bootstrap): Extend the virtual mapping area
+	according to memory size for at least being able to manage it.  But
+	look out for wrap and limit it to kernel adresses.  Remove duplicate
+	computing.
+
 2006-04-27  Richard Braun  <syn@hurdfr.org>
 	    Manuel Menal  <mmenal@hurdfr.org>
 
diff --git a/DEVELOPMENT b/DEVELOPMENT
index 9a13217..e596276 100644
--- a/DEVELOPMENT
+++ b/DEVELOPMENT
@@ -13,6 +13,14 @@ within the native Mach NE2000 NIC device driver, see
 Support for NORMA was removed on 2006-03-20.
 <URL:http://lists.gnu.org/archive/html/bug-hurd/2006-03/msg00007.html>.
 
-
 Be sure to check the ChangeLog and have a look at the repository at that
 tag's state if you want to work on those parts of GNU Mach.
+
+
+Starting with the application of the patch from
+<URL:http://savannah.gnu.org/bugs/index.php?func=detailitem&item_id=7118>,
+GNU Mach's usage of the machine's memory equipment is currently forced to
+be somewhere below 1 GiB, to make GNU Mach work at all on systems with
+such enlarged RAM installations.  This is--of course--not optimal.  See
+the calculation of and with `kernel_virtual_end' and `morevm' in
+i386/intel/pmap.c and `phys_last_addr' in i386/i386at/model_dep.c.
diff --git a/i386/i386at/model_dep.c b/i386/i386at/model_dep.c
index 8975805..362ba7f 100644
--- a/i386/i386at/model_dep.c
+++ b/i386/i386at/model_dep.c
@@ -207,6 +207,11 @@ mem_size_init()
 	printf("AT386 boot: physical memory from 0x%x to 0x%x\n",
 	       phys_first_addr, phys_last_addr);
 
+	/* Reserve 1/16 of the memory address space for virtual mappings.
+	 * Yes, this loses memory.  Blame i386.  */
+	if (phys_last_addr > (VM_MAX_KERNEL_ADDRESS / 16) * 15)
+		phys_last_addr = (VM_MAX_KERNEL_ADDRESS / 16) * 15;
+
 	phys_first_addr = round_page(phys_first_addr);
 	phys_last_addr = trunc_page(phys_last_addr);
 }
diff --git a/i386/intel/pmap.c b/i386/intel/pmap.c
index fc56e87..540070b 100644
--- a/i386/intel/pmap.c
+++ b/i386/intel/pmap.c
@@ -627,7 +627,12 @@ void pmap_bootstrap()
 	 * and extends to a stupid arbitrary limit beyond that.
 	 */
 	kernel_virtual_start = phys_last_addr;
-	kernel_virtual_end = phys_last_addr + morevm;
+	kernel_virtual_end = phys_last_addr + morevm
+		+ (phys_last_addr - phys_first_addr) / 15;
+
+	if (kernel_virtual_end < phys_last_addr
+			|| kernel_virtual_end > VM_MAX_KERNEL_ADDRESS)
+		kernel_virtual_end = VM_MAX_KERNEL_ADDRESS;
 
 	/*
 	 * Allocate and clear a kernel page directory.
@@ -656,7 +661,7 @@ void pmap_bootstrap()
 		 * to allocate new kernel page tables later.
 		 * XX fix this
 		 */
-		for (va = phys_first_addr; va < phys_last_addr + morevm; )
+		for (va = phys_first_addr; va < kernel_virtual_end; )
 		{
 			pt_entry_t *pde = kernel_page_dir + lin2pdenum(kvtolin(va));
 			pt_entry_t *ptable = (pt_entry_t*)pmap_grab_page();