ack/plat/linuxppc/emu/emu.c

343 lines
6 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdbool.h>
#include <strings.h>
#include <math.h>
#include "emu.h"
#define BO4 (1<<0)
#define BO3 (1<<1)
#define BO2 (1<<2)
#define BO1 (1<<3)
#define BO0 (1<<4)
#define XER_SO (1<<31)
#define XER_OV (1<<30)
#define XER_CA (1<<29)
cpu_t cpu;
static inline bool carry(void)
{
fatal("carry() not supported yet");
}
/* Byte-swaps a 16-bit value. */
static inline uint16_t swb16(uint16_t n)
{
return
(((n >> 8) & 0xff) |
((n & 0xff) << 8));
}
/* Byte-swaps a 32-bit value. */
static inline uint32_t swb32(uint32_t n)
{
return
(((n & 0xff000000) >> 24) |
((n & 0x00ff0000) >> 8) |
((n & 0x0000ff00) << 8) |
((n & 0x000000ff) << 24));
}
/* Returns the state of a carry flag after a three-way add. */
static inline bool carry_3(uint32_t a, uint32_t b, uint32_t c)
{
if ((a+b) < a)
return true;
if ((a+b+c) < c)
return true;
return false;
}
static inline uint32_t reg(uint8_t n)
{
return cpu.gpr[n];
}
static inline uint32_t reg0(uint8_t n)
{
if (n == 0)
return 0;
return cpu.gpr[n];
}
/* Double to bytes */
static inline uint64_t d2b(double n)
{
return *(uint64_t*)&n;
}
/* Float to bytes */
static inline uint32_t f2b(float n)
{
return *(uint32_t*)&n;
}
/* Bytes to double */
static inline double b2d(uint64_t n)
{
return *(double*)&n;
}
/* Bytes to float */
static inline float b2f(uint32_t n)
{
return *(float*)&n;
}
static inline double fpr(uint8_t n)
{
return b2d(cpu.fpr[n]);
}
static inline uint32_t ext8(int8_t n)
{
return (n << 24) >> 24;
}
static inline uint32_t ext16(int16_t n)
{
return (n << 16) >> 16;
}
static inline uint32_t ext26(int32_t n)
{
return (n << 6) >> 6;
}
static bool getcr(uint8_t bit)
{
bit = 31 - bit; /* note PowerPC bit numbering */
return cpu.cr & (1<<bit);
}
static void setcr(uint8_t bit, bool value)
{
bit = 31 - bit; /* note PowerPC bit numbering */
cpu.cr = cpu.cr & ~(1<<bit) | (value<<bit);
}
static void setcr0(bool setcr0, uint32_t value)
{
if (setcr0)
{
setcr(0, (int32_t)value < 0);
setcr(1, (int32_t)value > 0);
setcr(2, value == 0);
setcr(3, cpu.xer & (1<<31));
}
}
static void setcr1(bool setcr1, uint64_t value)
{
if (setcr1)
fatal("setcr1 not implemented yet");
}
static void mcrf(uint8_t destfield, uint8_t srcfield)
{
fatal("mcrf not supported yet");
}
static void branch(uint8_t bo, uint8_t bi, uint32_t dest, bool a_bit, bool l_bit)
{
bool bo0 = bo & BO0;
bool bo1 = bo & BO1;
bool bo2 = bo & BO2;
bool bo3 = bo & BO3;
bool ctr_ok;
bool cond_ok;
if (!bo2)
cpu.ctr--;
ctr_ok = bo2 || (!!cpu.ctr ^ bo3);
cond_ok = bo0 || (!!(cpu.cr & (1<<(31-bi))) == bo1);
if (ctr_ok && cond_ok)
{
if (a_bit)
cpu.nia = dest;
else
cpu.nia = dest + cpu.cia;
}
if (l_bit)
cpu.lr = cpu.cia + 4;
}
static void read_multiple(uint32_t address, uint8_t reg)
{
while (reg != 32)
{
cpu.gpr[reg] = read_long(address);
reg++;
address += 4;
}
}
static void write_multiple(uint32_t address, uint8_t reg)
{
while (reg != 32)
{
write_long(address, cpu.gpr[reg]);
reg++;
address += 4;
}
}
static void read_string(uint32_t address, uint8_t reg, uint8_t bytes)
{
fatal("read_string not supported yet");
}
static void write_string(uint32_t address, uint8_t reg, uint8_t bytes)
{
fatal("write_string not supported yet");
}
static uint32_t addo(uint32_t a, uint32_t b, uint32_t c, bool set_o, bool set_c)
{
if (set_o)
fatal("can't use O bit in add yet");
if (set_c)
{
cpu.xer = cpu.xer & ~XER_CA;
if (carry_3(a, b, c))
cpu.xer = cpu.xer | XER_CA;
}
return a + b + c;
}
static uint32_t mulo(uint32_t a, uint32_t b, bool set_o)
{
if (set_o)
fatal("can't use O bit in mul yet");
return a * b;
}
static int32_t divo(int32_t a, int32_t b, bool set_o)
{
if (set_o)
fatal("can't use O bit in div yet");
if (b == 0)
return 0;
return a / b;
}
static uint32_t divuo(uint32_t a, uint32_t b, bool set_o)
{
if (set_o)
fatal("can't use O bit in divu yet");
if (b == 0)
return 0;
return a / b;
}
static void compares(int32_t a, int32_t b, uint8_t field)
{
uint8_t bit = field*4;
setcr(bit+0, a<b);
setcr(bit+1, a>b);
setcr(bit+2, a==b);
setcr(bit+3, cpu.xer & (1<<31));
}
static void compareu(uint32_t a, uint32_t b, uint8_t field)
{
uint8_t bit = field*4;
setcr(bit+0, a<b);
setcr(bit+1, a>b);
setcr(bit+2, a==b);
setcr(bit+3, cpu.xer & (1<<31));
}
static void comparef(double a, double b, uint8_t field)
{
uint8_t c;
if (isnan(a) || isnan(b))
c = 0x1;
else if (a < b)
c = 0x8;
else if (a > b)
c = 0x4;
else
c = 0x2;
uint8_t bit = 28 - field*4; /* note PowerPC bit numbering */
cpu.cr = cpu.cr & ~(0xf<<bit) | (c<<bit);
/* TODO: ordered/unordered, FSPCR, etc. */
}
static uint32_t cntlzw(uint32_t source)
{
return 32 - ffs(source);
}
static uint32_t popcntb(uint32_t source)
{
fatal("popcntb not supported");
}
static uint32_t rotate(uint32_t i, uint32_t shift)
{
return (i << shift) | (i >> (32-shift));
}
static uint32_t rlwnm(uint32_t source, uint8_t shift, uint8_t mb, uint8_t me)
{
uint8_t masksize = 1 + me - mb; /* me and mb are inclusive */
uint32_t mask = (((uint64_t)1<<masksize)-1) << (31 - me);
return rotate(source, shift) & mask;
}
static uint32_t rlwmi(uint32_t source, uint8_t shift, uint8_t mb, uint8_t me)
{
fatal("rlwmi not supported");
}
static void mtcrf(uint8_t fxm, uint32_t value)
{
fatal("mtcrf not supported");
}
static void dispatch(uint32_t value)
{
#include "dispatcher.h"
fatal("unimplemented instruction 0x%0x (major opcode %d)", value, value>>26);
}
void dump_state(FILE* stream)
{
int i;
fprintf(stream, "\n");
fprintf(stream, "pc=0x%08x lr=0x%08x ctr=0x%08x xer=0x%08x cr=0x%08x",
cpu.cia, cpu.lr, cpu.ctr, cpu.xer, cpu.cr);
for (i=0; i<32; i++)
{
if ((i % 4) == 0)
fprintf(stream, "\n");
fprintf(stream, "gpr%02d=0x%08x ", i, cpu.gpr[i]);
}
fprintf(stderr, "\n");
/* This might fail and cause a reentrant trap if cia is invalid, so
* do it last. */
fprintf(stream, "insn=0x%08x\n", read_long(cpu.cia));
}
void single_step(void)
{
uint32_t value = read_long(cpu.cia);
cpu.nia = cpu.cia + 4;
dispatch(value);
cpu.cia = cpu.nia;
}