* [Qemu-devel] [PATCH V4 03/18] target-i386: support a20 mask for NEC PC-9812
@ 2009-12-22 17:40 TAKEDA, toshiya
2009-12-22 22:05 ` Jamie Lokier
0 siblings, 1 reply; 2+ messages in thread
From: TAKEDA, toshiya @ 2009-12-22 17:40 UTC (permalink / raw)
To: qemu-devel
Signed-off-by: TAKEDA, toshiya <t-takeda@m1.interq.or.jp>
---
target-i386/cpu.h | 3 +++
target-i386/helper.c | 46 ++++++++++++++++++++++++++++++++++++++++------
2 files changed, 43 insertions(+), 6 deletions(-)
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index f3834b3..271cc20 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -405,6 +405,8 @@
#define CPUID_EXT3_IBS (1 << 10)
#define CPUID_EXT3_SKINIT (1 << 12)
+#define PRIVATE_FEATURE_PC98_A20MASK (1 << 0)
+
#define CPUID_VENDOR_INTEL_1 0x756e6547 /* "Genu" */
#define CPUID_VENDOR_INTEL_2 0x49656e69 /* "ineI" */
#define CPUID_VENDOR_INTEL_3 0x6c65746e /* "ntel" */
@@ -684,6 +686,7 @@ typedef struct CPUX86State {
uint32_t cpuid_model[12];
uint32_t cpuid_ext2_features;
uint32_t cpuid_ext3_features;
+ uint32_t private_features; /* private features not defined in CPUID */
uint32_t cpuid_apic_id;
int cpuid_vendor_override;
diff --git a/target-i386/helper.c b/target-i386/helper.c
index 730e396..53d9422 100644
--- a/target-i386/helper.c
+++ b/target-i386/helper.c
@@ -57,11 +57,18 @@ static const char *ext3_feature_name[] = {
NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
};
+static const char *private_feature_name[] = {
+ "pc98_a20mask", NULL, NULL, NULL, NULL, NULL, NULL, NULL,
+ NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
+ NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
+ NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
+};
static void add_flagname_to_bitmaps(const char *flagname, uint32_t *features,
uint32_t *ext_features,
uint32_t *ext2_features,
- uint32_t *ext3_features)
+ uint32_t *ext3_features,
+ uint32_t *private_features)
{
int i;
int found = 0;
@@ -86,6 +93,11 @@ static void add_flagname_to_bitmaps(const char *flagname, uint32_t *features,
*ext3_features |= 1 << i;
found = 1;
}
+ for ( i = 0 ; i < 32 ; i++ )
+ if (private_feature_name[i] && !strcmp (flagname, private_feature_name[i])) {
+ *private_features |= 1 << i;
+ found = 1;
+ }
if (!found) {
fprintf(stderr, "CPU feature %s not found\n", flagname);
}
@@ -99,6 +111,7 @@ typedef struct x86_def_t {
int model;
int stepping;
uint32_t features, ext_features, ext2_features, ext3_features;
+ uint32_t private_features;
uint32_t xlevel;
char model_id[48];
int vendor_override;
@@ -377,6 +390,7 @@ static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
char *featurestr, *name = strtok(s, ",");
uint32_t plus_features = 0, plus_ext_features = 0, plus_ext2_features = 0, plus_ext3_features = 0;
uint32_t minus_features = 0, minus_ext_features = 0, minus_ext2_features = 0, minus_ext3_features = 0;
+ uint32_t plus_private_features = 0, minus_private_features = 0;
uint32_t numvalue;
def = NULL;
@@ -395,16 +409,21 @@ static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
}
add_flagname_to_bitmaps("hypervisor", &plus_features,
- &plus_ext_features, &plus_ext2_features, &plus_ext3_features);
+ &plus_ext_features, &plus_ext2_features, &plus_ext3_features,
+ &plus_private_features);
featurestr = strtok(NULL, ",");
while (featurestr) {
char *val;
if (featurestr[0] == '+') {
- add_flagname_to_bitmaps(featurestr + 1, &plus_features, &plus_ext_features, &plus_ext2_features, &plus_ext3_features);
+ add_flagname_to_bitmaps(featurestr + 1, &plus_features,
+ &plus_ext_features, &plus_ext2_features, &plus_ext3_features,
+ &plus_private_features);
} else if (featurestr[0] == '-') {
- add_flagname_to_bitmaps(featurestr + 1, &minus_features, &minus_ext_features, &minus_ext2_features, &minus_ext3_features);
+ add_flagname_to_bitmaps(featurestr + 1, &minus_features,
+ &minus_ext_features, &minus_ext2_features, &minus_ext3_features,
+ &minus_private_features);
} else if ((val = strchr(featurestr, '='))) {
*val = 0; val++;
if (!strcmp(featurestr, "family")) {
@@ -481,10 +500,12 @@ static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
x86_cpu_def->ext_features |= plus_ext_features;
x86_cpu_def->ext2_features |= plus_ext2_features;
x86_cpu_def->ext3_features |= plus_ext3_features;
+ x86_cpu_def->private_features |= plus_private_features;
x86_cpu_def->features &= ~minus_features;
x86_cpu_def->ext_features &= ~minus_ext_features;
x86_cpu_def->ext2_features &= ~minus_ext2_features;
x86_cpu_def->ext3_features &= ~minus_ext3_features;
+ x86_cpu_def->private_features &= ~minus_private_features;
free(s);
return 0;
@@ -530,6 +551,7 @@ static int cpu_x86_register (CPUX86State *env, const char *cpu_model)
env->cpuid_ext2_features = def->ext2_features;
env->cpuid_xlevel = def->xlevel;
env->cpuid_ext3_features = def->ext3_features;
+ env->private_features = def->private_features;
{
const char *model_id = def->model_id;
int c, len, i;
@@ -571,7 +593,11 @@ void cpu_reset(CPUX86State *env)
env->hflags2 |= HF2_GIF_MASK;
cpu_x86_update_cr0(env, 0x60000010);
- env->a20_mask = ~0x0;
+ if (env->private_features & PRIVATE_FEATURE_PC98_A20MASK) {
+ env->a20_mask = 0xfffff;
+ } else {
+ env->a20_mask = ~0x0;
+ }
env->smbase = 0x30000;
env->idt.limit = 0xffff;
@@ -940,7 +966,15 @@ void cpu_x86_set_a20(CPUX86State *env, int a20_state)
/* when a20 is changed, all the MMU mappings are invalid, so
we must flush everything */
tlb_flush(env, 1);
- env->a20_mask = ~(1 << 20) | (a20_state << 20);
+ if (env->private_features & PRIVATE_FEATURE_PC98_A20MASK) {
+ if (a20_state) {
+ env->a20_mask = ~0x0;
+ } else {
+ env->a20_mask = 0xfffff;
+ }
+ } else {
+ env->a20_mask = ~(1 << 20) | (a20_state << 20);
+ }
}
}
--
1.6.4
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [Qemu-devel] [PATCH V4 03/18] target-i386: support a20 mask for NEC PC-9812
2009-12-22 17:40 [Qemu-devel] [PATCH V4 03/18] target-i386: support a20 mask for NEC PC-9812 TAKEDA, toshiya
@ 2009-12-22 22:05 ` Jamie Lokier
0 siblings, 0 replies; 2+ messages in thread
From: Jamie Lokier @ 2009-12-22 22:05 UTC (permalink / raw)
To: TAKEDA, toshiya; +Cc: qemu-devel
TAKEDA, toshiya wrote:
> @@ -940,7 +966,15 @@ void cpu_x86_set_a20(CPUX86State *env, int a20_state)
> /* when a20 is changed, all the MMU mappings are invalid, so
> we must flush everything */
> tlb_flush(env, 1);
> - env->a20_mask = ~(1 << 20) | (a20_state << 20);
> + if (env->private_features & PRIVATE_FEATURE_PC98_A20MASK) {
> + if (a20_state) {
> + env->a20_mask = ~0x0;
> + } else {
> + env->a20_mask = 0xfffff;
> + }
> + } else {
> + env->a20_mask = ~(1 << 20) | (a20_state << 20);
> + }
> }
> }
It seems strange to mix different styles in that way. How about this,
which I think makes the PC98 vs. PC difference clearer too:
if (a20_state) {
env->a20_mask = ~0x0;
} else if (env->private_features & PRIVATE_FEATURE_PC98_A20MASK) {
env->a20_mask = (1 << 20) - 1; /* A20 masks all bits >= 20. */
} else {
env->a20_mask = ~(1 << 20); /* A20 masks only bit 20. */
}
(When I say clearer, it's not _that_ obvious that these or the
original expressions store the right thing into "uint64
env->a20_mask", given these expressions are all of type "int", but, in
fact, they do owing to C type promotion rules. Same for the save/load
state).
-- Jamie
^ permalink raw reply [flat|nested] 2+ messages in thread
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2009-12-22 17:40 [Qemu-devel] [PATCH V4 03/18] target-i386: support a20 mask for NEC PC-9812 TAKEDA, toshiya
2009-12-22 22:05 ` Jamie Lokier
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