1
0
mirror of https://gitlab.os-k.eu/os-k-team/kvisc.git synced 2023-08-25 14:05:46 +02:00
kvisc/vm/pc/mem.c
2019-06-19 21:41:22 +02:00

194 lines
5.3 KiB
C

// The OS/K Team licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
#include <pc/arch.h>
//----------------------------------------------------------------------------//
#define CHK_ALIGN(type) \
if (addr % alignof(type) > 0) { \
_except(ctx, E_ALI, \
"Non-aligned memory access: 0x%012lX (0x%012lX) by %lu", \
addr, real, alignof(type)); \
}
//----------------------------------------------------------------------------//
static ulong readmem8(ctx_t *ctx, ulong real, ulong addr)
{
if (addr % 2 == 0) return (ulong)ctx->mp[real] & 0xFF;
else return ((ulong)ctx->mp[real] & 0xFF00) >> 8;
}
static ulong readmem16(ctx_t *ctx, ulong real, ulong addr)
{
CHK_ALIGN(ushort);
return (ulong)ctx->mp[real];
}
static ulong readmem32(ctx_t *ctx, ulong real, ulong addr)
{
CHK_ALIGN(uint);
ulong val = ctx->mp[real++];
val = val | ((ulong)ctx->mp[real] << 16);
return val;
}
static ulong readmem64(ctx_t *ctx, ulong real, ulong addr)
{
CHK_ALIGN(ulong);
ulong val = (ulong)ctx->mp[real++];
val = val | ((ulong)ctx->mp[real++] << 16);
val = val | ((ulong)ctx->mp[real++] << 32);
val = val | ((ulong)ctx->mp[real] << 48);
return val;
}
//----------------------------------------------------------------------------//
static void writemem8(ctx_t *ctx, ulong val, ulong real, ulong addr)
{
ushort v = ctx->mp[real];
if (!(addr % 2)) {
ctx->mp[real] = (v & 0xFF00) | (val & 0xFF);
}
else {
ctx->mp[real] = (v & 0xFF) | (((val & 0xFF) << 8));
}
}
static void writemem16(ctx_t *ctx, ulong val, ulong real, ulong addr)
{
CHK_ALIGN(ushort);
ctx->mp[real] = val & 0xFFFF;
}
static void writemem32(ctx_t *ctx, ulong val, ulong real, ulong addr)
{
CHK_ALIGN(uint);
ctx->mp[real++] = val & 0xFFFF;
ctx->mp[real] = (val >> 16) & 0xFFFF;
}
static void writemem64(ctx_t *ctx, ulong val, ulong real, ulong addr)
{
CHK_ALIGN(ulong);
ctx->mp[real++] = val;
ctx->mp[real++] = (val >> 16) & 0xFFFF;
ctx->mp[real++] = (val >> 32) & 0xFFFF;
ctx->mp[real] = (val >> 48) & 0xFFFF;
}
//----------------------------------------------------------------------------//
#define CHK_RANGE() \
if (addr < MEMOFF || real >= MEMSIZE) { \
_except(ctx, E_ACC, \
"Invalid MEM access: 0x%012lX (0x%012lX)", addr, real); \
}
#define GETREAL() \
addr += cr2; \
ulong real = addr2real(addr)
#define SIGN_EXTEND(val, mask) \
(val & ((mask + 1) >> 1) \
? (val | ~mask) \
: val)
//----------------------------------------------------------------------------//
ulong readmem(ctx_t *ctx, ulong addr, uint len)
{
GETREAL();
CHK_RANGE();
ulong val;
switch (len) {
case 1:
val = readmem8(ctx, real, addr);
val = SIGN_EXTEND(val, 0xFF);
break;
case 2:
val = readmem16(ctx, real, addr);
val = SIGN_EXTEND(val, 0xFFFF);
break;
case 4:
val = readmem32(ctx, real, addr);
val = SIGN_EXTEND(val, 0xFFFFFFFFUL);
break;
case 8:
return readmem64(ctx, real, addr);
default: logerr("readmem() bad length %d!\n", len); abort();
}
return val;
}
void writemem(ctx_t *ctx, ulong val, ulong addr, uint len)
{
GETREAL();
CHK_RANGE();
// log("writemem: 0x%lX: 0x%lX (%d)\n", addr, val, len);
switch (len) {
case 1: writemem8(ctx, val, real, addr); break;
case 2: writemem16(ctx, val, real, addr); break;
case 4: writemem32(ctx, val, real, addr); break;
case 8: writemem64(ctx, val, real, addr); break;
default: logerr("writemem() bad length %d!\n", len); abort();
}
}
//----------------------------------------------------------------------------//
//
// The following functions zero-extend rather than sign-extend
//
ulong readmemzx(ctx_t *ctx, ulong addr, uint len)
{
GETREAL();
CHK_RANGE();
switch (len) {
case 1: return readmem8(ctx, real, addr); break;
case 2: return readmem16(ctx, real, addr); break;
case 4: return readmem32(ctx, real, addr); break;
case 8: return readmem64(ctx, real, addr); break;
default: logerr("readmemzx() bad length %d!\n", len); abort();
}
}
void writememzx(ctx_t *ctx, ulong val, ulong addr, uint len)
{
GETREAL();
CHK_RANGE();
switch (len) {
case 1: writemem8(ctx, val, real, addr); break;
case 2: writemem16(ctx, val, real, addr); break;
case 4: writemem32(ctx, val, real, addr); break;
case 8: writemem64(ctx, val, real, addr); break;
default: logerr("writememzx() bad length %d!\n", len); abort();
}
}