From 4eae16a077bb6d30a499efe78170b521e6e5e879 Mon Sep 17 00:00:00 2001 From: Keir Fraser Date: Tue, 28 Aug 2012 22:40:45 +0100 Subject: [PATCH] x86: Prefer multiboot-provided e820 over bios-provided e801 memory info. Some UEFI systems do not provide e820 information. In this case we should take the detailed memory map provided by a multiboot-capable loader, rather than rely on very conservative values from the e801 bios call. Using the latter on any modern system really hardly makes good sense. [Excellent candidate for 4.1 backport] Signed-off-by: Keir Fraser Tested-by: Jonathan Tripathy --- xen/arch/x86/setup.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c index 3024fec8fd..7fffdc4a95 100644 --- a/xen/arch/x86/setup.c +++ b/xen/arch/x86/setup.c @@ -690,17 +690,6 @@ void __init __start_xen(unsigned long mbi_p) { memmap_type = "Xen-e820"; } - else if ( bootsym(lowmem_kb) ) - { - memmap_type = "Xen-e801"; - e820_raw[0].addr = 0; - e820_raw[0].size = bootsym(lowmem_kb) << 10; - e820_raw[0].type = E820_RAM; - e820_raw[1].addr = 0x100000; - e820_raw[1].size = bootsym(highmem_kb) << 10; - e820_raw[1].type = E820_RAM; - e820_raw_nr = 2; - } else if ( mbi->flags & MBI_MEMMAP ) { memmap_type = "Multiboot-e820"; @@ -738,6 +727,17 @@ void __init __start_xen(unsigned long mbi_p) bytes += map->size + 4; } } + else if ( bootsym(lowmem_kb) ) + { + memmap_type = "Xen-e801"; + e820_raw[0].addr = 0; + e820_raw[0].size = bootsym(lowmem_kb) << 10; + e820_raw[0].type = E820_RAM; + e820_raw[1].addr = 0x100000; + e820_raw[1].size = bootsym(highmem_kb) << 10; + e820_raw[1].type = E820_RAM; + e820_raw_nr = 2; + } else if ( mbi->flags & MBI_MEMLIMITS ) { memmap_type = "Multiboot-e801"; -- 2.30.2