[SeaBIOS] [PATCH 1/2] Add CPUID emulation
Kevin O'Connor
kevin at koconnor.net
Sun Jan 29 19:46:21 CET 2012
On Wed, Jan 25, 2012 at 06:45:28PM +0100, Rudolf Marek wrote:
> Hi all
>
> As requested here is the first patch.
How about this patch instead?
-Kevin
commit c2228f401c13e0b300c6b1fcc43cc9097f47bb43
Author: Kevin O'Connor <kevin at koconnor.net>
Date: Sun Jan 29 13:30:56 2012 -0500
Detect CPUID instruction before using it.
Enable SeaBIOS to work on 386/486 machines that don't have CPUID
instruction.
Based on patch by Rudolf Marek.
Signed-off-by: Rudolf Marek <r.marek at assembler.cz>
Signed-off-by: Kevin O'Connor <kevin at koconnor.net>
diff --git a/src/bregs.h b/src/bregs.h
index f026fa8..577effc 100644
--- a/src/bregs.h
+++ b/src/bregs.h
@@ -11,6 +11,7 @@
#define F_CF (1<<0)
#define F_ZF (1<<6)
#define F_IF (1<<9)
+#define F_ID (1<<21)
// CR0 flags
#define CR0_PG (1<<31) // Paging
diff --git a/src/mptable.c b/src/mptable.c
index 103f462..3422212 100644
--- a/src/mptable.c
+++ b/src/mptable.c
@@ -35,7 +35,7 @@ mptable_init(void)
// Detect cpu info
u32 cpuid_signature, ebx, ecx, cpuid_features;
- cpuid(1, &cpuid_signature, &ebx, &ecx, &cpuid_features);
+ get_cpuid(1, &cpuid_signature, &ebx, &ecx, &cpuid_features);
if (! cpuid_signature) {
// Use default values.
cpuid_signature = 0x600;
diff --git a/src/mtrr.c b/src/mtrr.c
index 0548043..b6a8427 100644
--- a/src/mtrr.c
+++ b/src/mtrr.c
@@ -37,7 +37,7 @@ void mtrr_setup(void)
return;
u32 eax, ebx, ecx, edx, cpuid_features;
- cpuid(1, &eax, &ebx, &ecx, &cpuid_features);
+ get_cpuid(1, &eax, &ebx, &ecx, &cpuid_features);
if (!(cpuid_features & CPUID_MTRR))
return;
if (!(cpuid_features & CPUID_MSR))
@@ -82,11 +82,11 @@ void mtrr_setup(void)
// Set variable MTRRs
int phys_bits = 36;
- cpuid(0x80000000u, &eax, &ebx, &ecx, &edx);
+ get_cpuid(0x80000000u, &eax, &ebx, &ecx, &edx);
if (eax >= 0x80000008) {
- /* Get physical bits from leaf 0x80000008 (if available) */
- cpuid(0x80000008u, &eax, &ebx, &ecx, &edx);
- phys_bits = eax & 0xff;
+ /* Get physical bits from leaf 0x80000008 (if available) */
+ get_cpuid(0x80000008u, &eax, &ebx, &ecx, &edx);
+ phys_bits = eax & 0xff;
}
u64 phys_mask = ((1ull << phys_bits) - 1);
for (i=0; i<vcnt; i++) {
diff --git a/src/paravirt.h b/src/paravirt.h
index 4a370a0..4014943 100644
--- a/src/paravirt.h
+++ b/src/paravirt.h
@@ -11,10 +11,12 @@
static inline int kvm_para_available(void)
{
+ if (CONFIG_COREBOOT)
+ return 0;
unsigned int eax, ebx, ecx, edx;
char signature[13];
- cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
+ get_cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
memcpy(signature + 0, &ebx, 4);
memcpy(signature + 4, &ecx, 4);
memcpy(signature + 8, &edx, 4);
diff --git a/src/smbios.c b/src/smbios.c
index fe1e183..9c8df98 100644
--- a/src/smbios.c
+++ b/src/smbios.c
@@ -255,7 +255,7 @@ smbios_init_type_4(void *start, unsigned int cpu_number)
if (!qemu_cfg_smbios_load_field(4, offsetof(struct smbios_type_4,
processor_id), p->processor_id)) {
u32 cpuid_signature, ebx, ecx, cpuid_features;
- cpuid(1, &cpuid_signature, &ebx, &ecx, &cpuid_features);
+ get_cpuid(1, &cpuid_signature, &ebx, &ecx, &cpuid_features);
p->processor_id[0] = cpuid_signature;
p->processor_id[1] = cpuid_features;
}
diff --git a/src/smp.c b/src/smp.c
index 8c077a1..e36f960 100644
--- a/src/smp.c
+++ b/src/smp.c
@@ -73,7 +73,7 @@ smp_probe(void)
{
ASSERT32FLAT();
u32 eax, ebx, ecx, cpuid_features;
- cpuid(1, &eax, &ebx, &ecx, &cpuid_features);
+ get_cpuid(1, &eax, &ebx, &ecx, &cpuid_features);
if (eax < 1 || !(cpuid_features & CPUID_APIC)) {
// No apic - only the main cpu is present.
dprintf(1, "No apic - only the main cpu is present.\n");
diff --git a/src/util.c b/src/util.c
index ed73d63..7141f5d 100644
--- a/src/util.c
+++ b/src/util.c
@@ -8,6 +8,22 @@
#include "bregs.h" // struct bregs
#include "config.h" // BUILD_STACK_ADDR
+void
+get_cpuid(u32 index, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx)
+{
+ // Check for cpu id
+ u32 origflags = save_flags();
+ restore_flags(origflags ^ F_ID);
+ u32 newflags = save_flags();
+ restore_flags(origflags);
+
+ if (((origflags ^ newflags) & F_ID) != F_ID)
+ // no cpuid
+ *eax = *ebx = *ecx = *edx = 0;
+ else
+ cpuid(index, eax, ebx, ecx, edx);
+}
+
/****************************************************************
* 16bit calls
diff --git a/src/util.h b/src/util.h
index eecba8b..a69949d 100644
--- a/src/util.h
+++ b/src/util.h
@@ -18,15 +18,14 @@ static inline void irq_enable(void)
asm volatile("sti": : :"memory");
}
-static inline unsigned long irq_save(void)
+static inline u32 save_flags(void)
{
- unsigned long flags;
- asm volatile("pushfl ; popl %0" : "=g" (flags): :"memory");
- irq_disable();
+ u32 flags;
+ asm("pushfl ; popl %0" : "=rm" (flags));
return flags;
}
-static inline void irq_restore(unsigned long flags)
+static inline void restore_flags(u32 flags)
{
asm volatile("pushl %0 ; popfl" : : "g" (flags) : "memory", "cc");
}
@@ -196,6 +195,7 @@ struct descloc_s {
} PACKED;
// util.c
+void get_cpuid(u32 index, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx);
struct bregs;
inline void call16(struct bregs *callregs);
inline void call16big(struct bregs *callregs);
diff --git a/src/xen.c b/src/xen.c
index 4072793..5f4abdb 100644
--- a/src/xen.c
+++ b/src/xen.c
@@ -55,7 +55,7 @@ void xen_probe(void)
return;
for (base = 0x40000000; base < 0x40010000; base += 0x100) {
- cpuid(base, &eax, &ebx, &ecx, &edx);
+ get_cpuid(base, &eax, &ebx, &ecx, &edx);
memcpy(signature + 0, &ebx, 4);
memcpy(signature + 4, &ecx, 4);
memcpy(signature + 8, &edx, 4);
@@ -88,7 +88,7 @@ void xen_init_hypercalls(void)
if (!usingXen())
return;
- cpuid(xen_cpuid_base + 2, &eax, &ebx, &ecx, &edx);
+ get_cpuid(xen_cpuid_base + 2, &eax, &ebx, &ecx, &edx);
xen_hypercall_page = (unsigned long)memalign_high(PAGE_SIZE, eax*PAGE_SIZE);
if (!xen_hypercall_page)
@@ -99,7 +99,7 @@ void xen_init_hypercalls(void)
wrmsr(ebx, xen_hypercall_page + (i << 12) + i);
/* Print version information. */
- cpuid(xen_cpuid_base + 1, &eax, &ebx, &ecx, &edx);
+ get_cpuid(xen_cpuid_base + 1, &eax, &ebx, &ecx, &edx);
hypercall_xen_version(XENVER_extraversion, extraversion);
dprintf(1, "Detected Xen v%u.%u%s\n", eax >> 16, eax & 0xffff, extraversion);
}
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