[Xen-devel] [RFC PATCH 17/33] Support loading an initrd when running on Xen

[Chris Wright <chrisw@xxxxxxxxxxxx>]

Due to the initial physical memory layout when booting on Xen, the initrd
image ends up below min_low_pfn (as registered with the bootstrap memory
allocator).  Add Xen subarch support to enable initrd_below_start_ok flag,
and disable initrd_reserve_bootmem.

Signed-off-by: Ian Pratt <ian.pratt@xxxxxxxxxxxxx>
Signed-off-by: Christian Limpach <Christian.Limpach@xxxxxxxxxxxx>
Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
---
 arch/i386/kernel/setup.c                    |    4 +++-
 include/asm-i386/mach-xen/setup_arch_post.h |    6 ++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff -r f4c730a90338 arch/i386/kernel/setup.c
--- a/arch/i386/kernel/setup.c  Tue Jun 13 23:54:44 2006 -0700
+++ b/arch/i386/kernel/setup.c  Wed Jun 14 00:02:16 2006 -0700
@@ -1205,6 +1205,7 @@ extern unsigned long __init setup_memory
 extern unsigned long __init setup_memory(void);
 extern void zone_sizes_init(void);
 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
+int initrd_reserve_bootmem = 1;
 
 void __init setup_bootmem_allocator(void)
 {
@@ -1265,7 +1266,8 @@ void __init setup_bootmem_allocator(void
 #ifdef CONFIG_BLK_DEV_INITRD
        if (LOADER_TYPE && INITRD_START) {
                if (INITRD_START + INITRD_SIZE <= (max_low_pfn << PAGE_SHIFT)) {
-                       reserve_bootmem(INITRD_START, INITRD_SIZE);
+                       if (initrd_reserve_bootmem)
+                               reserve_bootmem(INITRD_START, INITRD_SIZE);
                        initrd_start =
                                INITRD_START ? INITRD_START + PAGE_OFFSET : 0;
                        initrd_end = initrd_start+INITRD_SIZE;
diff -r f4c730a90338 arch/i386/mach-xen/setup-xen.c
--- a/arch/i386/mach-xen/setup-xen.c    Tue Jun 13 23:54:44 2006 -0700
+++ b/arch/i386/mach-xen/setup-xen.c    Wed Jun 14 00:02:16 2006 -0700
@@ -5,6 +5,8 @@
 #include <linux/config.h>
 #include <linux/module.h>
 #include <linux/mm.h>
+#include <linux/bootmem.h>
+#include <linux/initrd.h>
 
 #include <asm/e820.h>
 #include <asm/setup.h>
@@ -68,4 +70,10 @@ void __init machine_specific_arch_setup(
        memcpy(saved_command_line, xen_start_info->cmd_line,
               MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ?
               COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE);
+
+       if (INITRD_START &&
+           INITRD_START + PAGE_OFFSET < min_low_pfn << PAGE_SHIFT) {
+               initrd_reserve_bootmem = 0;
+               initrd_below_start_ok = 1;
+       }
 }
diff -r f4c730a90338 include/asm-i386/setup.h
--- a/include/asm-i386/setup.h  Tue Jun 13 23:54:44 2006 -0700
+++ b/include/asm-i386/setup.h  Wed Jun 14 00:02:16 2006 -0700
@@ -66,6 +66,7 @@ extern unsigned char boot_params[PARAM_S
 #define LOWMEMSIZE()   (0x9f000)
 
 extern unsigned long init_pg_tables_end;
+extern int initrd_reserve_bootmem;
 
 struct e820entry;
 

--

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel