diff options
Diffstat (limited to 'arch/x86/boot/cpucheck.c')
| -rw-r--r-- | arch/x86/boot/cpucheck.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/x86/boot/cpucheck.c b/arch/x86/boot/cpucheck.c index 100a9a10076a..1fd7d575092e 100644 --- a/arch/x86/boot/cpucheck.c +++ b/arch/x86/boot/cpucheck.c @@ -27,6 +27,7 @@ #include <asm/processor-flags.h> #include <asm/required-features.h> #include <asm/msr-index.h> +#include "string.h" static u32 err_flags[NCAPINTS]; @@ -67,6 +68,13 @@ static int is_transmeta(void) cpu_vendor[2] == A32('M', 'x', '8', '6'); } +static int is_intel(void) +{ + return cpu_vendor[0] == A32('G', 'e', 'n', 'u') && + cpu_vendor[1] == A32('i', 'n', 'e', 'I') && + cpu_vendor[2] == A32('n', 't', 'e', 'l'); +} + /* Returns a bitmask of which words we have error bits in */ static int check_cpuflags(void) { @@ -153,6 +161,19 @@ int check_cpu(int *cpu_level_ptr, int *req_level_ptr, u32 **err_flags_ptr) asm("wrmsr" : : "a" (eax), "d" (edx), "c" (ecx)); err = check_cpuflags(); + } else if (err == 0x01 && + !(err_flags[0] & ~(1 << X86_FEATURE_PAE)) && + is_intel() && cpu.level == 6 && + (cpu.model == 9 || cpu.model == 13)) { + /* PAE is disabled on this Pentium M but can be forced */ + if (cmdline_find_option_bool("forcepae")) { + puts("WARNING: Forcing PAE in CPU flags\n"); + set_bit(X86_FEATURE_PAE, cpu.flags); + err = check_cpuflags(); + } + else { + puts("WARNING: PAE disabled. Use parameter 'forcepae' to enable at your own risk!\n"); + } } if (err_flags_ptr) |