--- arch/x86/kernel/e820.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) Index: linux-2.6/arch/x86/kernel/e820.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/e820.c +++ linux-2.6/arch/x86/kernel/e820.c @@ -835,6 +835,8 @@ static int __init parse_memopt(char *p) } early_param("mem", parse_memopt); +static bool __initdata exactmap_parsed; + static int __init parse_memmap_one(char *p) { char *oldp; @@ -844,6 +846,10 @@ static int __init parse_memmap_one(char return -EINVAL; if (!strncmp(p, "exactmap", 8)) { + if (exactmap_parsed) + return 0; + + exactmap_parsed = true; #ifdef CONFIG_CRASH_DUMP /* * If we are doing a crash dump, we still need to know @@ -879,6 +885,12 @@ static int __init parse_memmap_one(char } static int __init parse_memmap_opt(char *str) { + char *p = boot_command_line; + + p = strstr(p, "exactmap"); + if (p) + parse_memmap_one("exactmap"); + while (str) { char *k = strchr(str, ',');