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authorRichard Henderson <rth@twiddle.net>2011-04-28 07:29:27 -0700
committerMatt Turner <mattst88@gmail.com>2013-11-16 16:33:12 -0800
commit994dcf7055df88623d25f3593b931a018a76b502 (patch)
treec3708ed5b2558e82b88ef15e533797a400b361e5 /arch/alpha
parenta47e5bb5764f029f989a182b0dd2d4cce69f8b14 (diff)
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alpha: Notice if we're being run under QEMU
When building a generic kernel, do a run-time check on the serial number, like we do for MILO. When building a custom kernel, make this a configure-time check. Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'arch/alpha')
-rw-r--r--arch/alpha/Kconfig14
-rw-r--r--arch/alpha/include/asm/machvec.h18
-rw-r--r--arch/alpha/kernel/setup.c13
3 files changed, 38 insertions, 7 deletions
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 135c674eaf9e..51cc8c353164 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -488,6 +488,20 @@ config VGA_HOSE
which always have multiple hoses, and whose consoles support it.
+config ALPHA_QEMU
+ bool "Run under QEMU emulation"
+ depends on !ALPHA_GENERIC
+ ---help---
+ Assume the presence of special features supported by QEMU PALcode
+ that reduce the overhead of system emulation.
+
+ Generic kernels will auto-detect QEMU. But when building a
+ system-specific kernel, the assumption is that we want to
+ elimiate as many runtime tests as possible.
+
+ If unsure, say N.
+
+
config ALPHA_SRM
bool "Use SRM as bootloader" if ALPHA_CABRIOLET || ALPHA_AVANTI_CH || ALPHA_EB64P || ALPHA_PC164 || ALPHA_TAKARA || ALPHA_EB164 || ALPHA_ALCOR || ALPHA_MIATA || ALPHA_LX164 || ALPHA_SX164 || ALPHA_NAUTILUS || ALPHA_NONAME
depends on TTY
diff --git a/arch/alpha/include/asm/machvec.h b/arch/alpha/include/asm/machvec.h
index 72dbf2359270..4ac90167d346 100644
--- a/arch/alpha/include/asm/machvec.h
+++ b/arch/alpha/include/asm/machvec.h
@@ -126,13 +126,19 @@ extern struct alpha_machine_vector alpha_mv;
#ifdef CONFIG_ALPHA_GENERIC
extern int alpha_using_srm;
+extern int alpha_using_qemu;
#else
-#ifdef CONFIG_ALPHA_SRM
-#define alpha_using_srm 1
-#else
-#define alpha_using_srm 0
-#endif
+# ifdef CONFIG_ALPHA_SRM
+# define alpha_using_srm 1
+# else
+# define alpha_using_srm 0
+# endif
+# ifdef CONFIG_ALPHA_QEMU
+# define alpha_using_qemu 1
+# else
+# define alpha_using_qemu 0
+# endif
#endif /* GENERIC */
-#endif
+#endif /* __KERNEL__ */
#endif /* __ALPHA_MACHVEC_H */
diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c
index 9e3107cc5ebb..c38d6a1b9066 100644
--- a/arch/alpha/kernel/setup.c
+++ b/arch/alpha/kernel/setup.c
@@ -115,10 +115,17 @@ unsigned long alpha_agpgart_size = DEFAULT_AGP_APER_SIZE;
#ifdef CONFIG_ALPHA_GENERIC
struct alpha_machine_vector alpha_mv;
+#endif
+
+#ifndef alpha_using_srm
int alpha_using_srm;
EXPORT_SYMBOL(alpha_using_srm);
#endif
+#ifndef alpha_using_qemu
+int alpha_using_qemu;
+#endif
+
static struct alpha_machine_vector *get_sysvec(unsigned long, unsigned long,
unsigned long);
static struct alpha_machine_vector *get_sysvec_byname(const char *);
@@ -529,11 +536,15 @@ setup_arch(char **cmdline_p)
atomic_notifier_chain_register(&panic_notifier_list,
&alpha_panic_block);
-#ifdef CONFIG_ALPHA_GENERIC
+#ifndef alpha_using_srm
/* Assume that we've booted from SRM if we haven't booted from MILO.
Detect the later by looking for "MILO" in the system serial nr. */
alpha_using_srm = strncmp((const char *)hwrpb->ssn, "MILO", 4) != 0;
#endif
+#ifndef alpha_using_qemu
+ /* Similarly, look for QEMU. */
+ alpha_using_qemu = strstr((const char *)hwrpb->ssn, "QEMU") != 0;
+#endif
/* If we are using SRM, we want to allow callbacks
as early as possible, so do this NOW, and then