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VAX, MicroVAX2: Update ROM memory access to use common code

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This commit is contained in:
Mark Pizzolato 2017-01-05 05:53:00 -08:00
parent b800587f34
commit 6e31112469
2 changed files with 8 additions and 107 deletions
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56
VAX/vax630_sysdev.c
View File

@ -132,7 +132,6 @@ int32 ka_bdr = BDR_BRKENB; /* KA630 boot diag */
int32 ka_mser = 0; /* KA630 mem sys err */
int32 ka_cear = 0; /* KA630 cpu err */
int32 ka_dear = 0; /* KA630 dma err */
static uint32 rom_delay = 0;
t_bool ka_diag_full = FALSE;
t_bool ka_hltenab = TRUE; /* Halt Enable / Autoboot flag */
@ -292,62 +291,15 @@ DEVICE sysd_dev = {
issues with the embedded timing loops.
*/
int32 rom_swapb(int32 val)
int32 rom_rd (int32 pa)
{
return ((val << 24) & 0xff000000) | (( val << 8) & 0xff0000) |
((val >> 8) & 0xff00) | ((val >> 24) & 0xff);
}
volatile int32 rom_loopval = 0;
int32 rom_read_delay (int32 val)
{
uint32 i, l = rom_delay;
int32 rg = ((pa - ROMBASE) & ROMAMASK) >> 2;
int32 val = rom[rg];
if (rom_unit.flags & UNIT_NODELAY)
return val;
/* Calibrate the loop delay factor when first used.
Do this 4 times to and use the largest value computed. */
if (rom_delay == 0) {
uint32 ts, te, c = 10000, samples = 0;
while (1) {
c = c * 2;
te = sim_os_msec();
while (te == (ts = sim_os_msec ())); /* align on ms tick */
/* This is merely a busy wait with some "work" that won't get optimized
away by a good compiler. loopval always is zero. To avoid smart compilers,
the loopval variable is referenced in the function arguments so that the
function expression is not loop invariant. It also must be referenced
by subsequent code or to avoid the whole computation being eliminated. */
for (i = 0; i < c; i++)
rom_loopval |= (rom_loopval + ts) ^ rom_swapb (rom_swapb (rom_loopval + ts));
te = sim_os_msec ();
if ((te - ts) < 50) /* sample big enough? */
continue;
if (rom_delay < (rom_loopval + (c / (te - ts) / 1000) + 1))
rom_delay = rom_loopval + (c / (te - ts) / 1000) + 1;
if (++samples >= 4)
break;
c = c / 2;
}
if (rom_delay < 5)
rom_delay = 5;
}
for (i = 0; i < l; i++)
rom_loopval |= (rom_loopval + val) ^ rom_swapb (rom_swapb (rom_loopval + val));
return val + rom_loopval;
}
int32 rom_rd (int32 pa)
{
int32 rg = ((pa - ROMBASE) & ROMAMASK) >> 2;
return rom_read_delay (rom[rg]);
return sim_rom_read_with_delay (val);
}
void rom_wr_B (int32 pa, int32 val)

59
VAX/vax_sysdev.c
View File

@ -252,7 +252,6 @@ t_bool tmr_inst[2] = { 0 }; /* wait instructions vs
int32 ssc_adsm[2] = { 0 }; /* addr strobes */
int32 ssc_adsk[2] = { 0 };
int32 cdg_dat[CDASIZE >> 2]; /* cache data */
static uint32 rom_delay = 0;
t_stat rom_ex (t_value *vptr, t_addr exta, UNIT *uptr, int32 sw);
t_stat rom_dep (t_value val, t_addr exta, UNIT *uptr, int32 sw);
@ -334,7 +333,6 @@ extern void cpu_idle (void);
UNIT rom_unit = { UDATA (NULL, UNIT_FIX+UNIT_BINK, ROMSIZE) };
REG rom_reg[] = {
{ DRDATAD (DELAY, rom_delay, 32, "ROM access delay count"), PV_LEFT + REG_RO },
{ NULL }
};
@ -539,31 +537,15 @@ DEVICE sysd_dev = {
issues with the embedded timing loops.
*/
int32 rom_swapb(int32 val)
int32 rom_rd (int32 pa)
{
return ((val << 24) & 0xff000000) | (( val << 8) & 0xff0000) |
((val >> 8) & 0xff00) | ((val >> 24) & 0xff);
}
volatile int32 rom_loopval = 0;
int32 rom_read_delay (int32 val)
{
uint32 i, l = rom_delay;
int32 rg = ((pa - ROMBASE) & ROMAMASK) >> 2;
int32 val = rom[rg];
if (rom_unit.flags & UNIT_NODELAY)
return val;
for (i = 0; i < l; i++)
rom_loopval |= (rom_loopval + val) ^ rom_swapb (rom_swapb (rom_loopval + val));
return val + rom_loopval;
}
int32 rom_rd (int32 pa)
{
int32 rg = ((pa - ROMBASE) & ROMAMASK) >> 2;
return rom_read_delay (rom[rg]);
return sim_rom_read_with_delay (val);
}
void rom_wr_B (int32 pa, int32 val)
@ -609,39 +591,6 @@ t_stat rom_reset (DEVICE *dptr)
if (rom == NULL)
rom = (uint32 *) calloc (ROMSIZE >> 2, sizeof (uint32));
/* Calibrate the loop delay factor at startup.
Do this 4 times and use the largest value computed.
The goal here is to come up with a delay factor which will throttle
a 6 byte delay loop running from ROM address space to execute
1 instruction per usec */
if (rom_delay == 0) {
uint32 i, ts, te, c = 10000, samples = 0;
while (1) {
c = c * 2;
te = sim_os_msec();
while (te == (ts = sim_os_msec ())); /* align on ms tick */
/* This is merely a busy wait with some "work" that won't get optimized
away by a good compiler. loopval always is zero. To avoid smart compilers,
the loopval variable is referenced in the function arguments so that the
function expression is not loop invariant. It also must be referenced
by subsequent code to avoid the whole computation being eliminated. */
for (i = 0; i < c; i++)
rom_loopval |= (rom_loopval + ts) ^ rom_swapb (rom_swapb (rom_loopval + ts));
te = sim_os_msec ();
if ((te - ts) < 50) /* sample big enough? */
continue;
if (rom_delay < (rom_loopval + (c / (te - ts) / 1000) + 1))
rom_delay = rom_loopval + (c / (te - ts) / 1000) + 1;
if (++samples >= 4)
break;
c = c / 2;
}
if (rom_delay < 5)
rom_delay = 5;
}
if (rom == NULL)
return SCPE_MEM;
return SCPE_OK;