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>
This commit is contained in:
Richard Henderson 2011-04-28 07:29:27 -07:00 committed by Matt Turner
parent a47e5bb576
commit 994dcf7055
3 changed files with 38 additions and 7 deletions

View file

@ -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

View file

@ -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 */

View file

@ -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