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More real ELF loading and brk handling; more tests pass.

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This commit is contained in:
David Given 2018-06-07 13:03:36 +09:00
parent 396795105f
commit 2682c125e0
1 changed files with 80 additions and 41 deletions
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121
plat/linux68k/emu/sim.c
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@ -1,6 +1,8 @@
#include <stdio.h> #include <stdio.h>
#include <stdlib.h> #include <stdlib.h>
#include <stdarg.h> #include <stdarg.h>
#include <stdint.h>
#include <string.h>
#include <time.h> #include <time.h>
#include <unistd.h> #include <unistd.h>
#include <errno.h> #include <errno.h>
@ -13,12 +15,11 @@ void disassemble_program();
#define RAM_BASE 0x08000000 #define RAM_BASE 0x08000000
#define RAM_TOP 0x08100000 #define RAM_TOP 0x08100000
#define BRK_TOP (RAM_TOP - 0x1000)
#define INIT_SP RAM_TOP #define INIT_SP RAM_TOP
#define INIT_PC 0x08000054 #define INIT_PC 0x08000054
#define BRK_BOTTOM (RAM_BASE + 0x20000)
#define BRK_TOP (RAM_TOP - 0x1000)
/* Read/write macros */ /* Read/write macros */
#define READ_BYTE(BASE, ADDR) (BASE)[ADDR] #define READ_BYTE(BASE, ADDR) (BASE)[ADDR]
#define READ_WORD(BASE, ADDR) (((BASE)[ADDR]<<8) | \ #define READ_WORD(BASE, ADDR) (((BASE)[ADDR]<<8) | \
@ -40,23 +41,24 @@ void disassemble_program();
static void exit_error(char* fmt, ...); static void exit_error(char* fmt, ...);
static void emulated_syscall(void); static void emulated_syscall(void);
unsigned int cpu_read_byte(unsigned int address); uint32_t cpu_read_byte(uint32_t address);
unsigned int cpu_read_word(unsigned int address); uint32_t cpu_read_word(uint32_t address);
unsigned int cpu_read_long(unsigned int address); uint32_t cpu_read_long(uint32_t address);
void cpu_write_byte(unsigned int address, unsigned int value); void cpu_write_byte(uint32_t address, uint32_t value);
void cpu_write_word(unsigned int address, unsigned int value); void cpu_write_word(uint32_t address, uint32_t value);
void cpu_write_long(unsigned int address, unsigned int value); void cpu_write_long(uint32_t address, uint32_t value);
unsigned char g_ram[RAM_TOP - RAM_BASE]; unsigned char g_ram[RAM_TOP - RAM_BASE];
unsigned int brkpos = BRK_BOTTOM; uint32_t brkbase = RAM_BASE;
uint32_t brkpos = RAM_BASE;
uint32_t entrypoint = RAM_BASE;
/* Exit with an error message. Use printf syntax. */ /* Exit with an error message. Use printf syntax. */
void exit_error(char* fmt, ...) void exit_error(char* fmt, ...)
{ {
static int guard_val = 0; static int guard_val = 0;
char buff[100]; char buff[100];
unsigned int pc; uint32_t pc;
va_list args; va_list args;
if(guard_val) if(guard_val)
@ -75,71 +77,78 @@ void exit_error(char* fmt, ...)
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
} }
static inline unsigned int transform_address(unsigned int address) static inline uint32_t transform_address(uint32_t address)
{ {
unsigned int i = (address & ADDRESS_MASK) - RAM_BASE; uint32_t i = (address & ADDRESS_MASK) - RAM_BASE;
if (i >= (unsigned int)(RAM_TOP - RAM_BASE)) if (i >= (uint32_t)(RAM_TOP - RAM_BASE))
exit_error("Attempted to read from RAM address %08x", address); exit_error("Attempted to read from RAM address %08x", address);
return i; return i;
} }
unsigned int cpu_read_long(unsigned int address) uint32_t cpu_read_long(uint32_t address)
{ {
switch (address) switch (address)
{ {
case 0x00: return INIT_SP; case 0x00: return INIT_SP;
case 0x04: return INIT_PC; case 0x04: return entrypoint;
case 0x80: emulated_syscall(); return 0x10000; case 0x80: emulated_syscall(); return 0x10000;
case 0x10000: return 0x4e734e73; /* rte; rte */ case 0x10000: return 0x4e734e73; /* rte; rte */
case 0x10004: return 0; case 0x10004: return 0;
default: return READ_LONG(g_ram, transform_address(address)); default:
{
uint32_t value = READ_LONG(g_ram, transform_address(address));
#if 0
printf("read %08x from %08x\n", value, address);
#endif
return value;
}
} }
} }
unsigned int cpu_read_word(unsigned int address) uint32_t cpu_read_word(uint32_t address)
{ {
unsigned int l = cpu_read_long(address & ~3); uint32_t l = cpu_read_long(address & ~3);
l >>= 16 - (address & 2)*8; l >>= 16 - (address & 2)*8;
return l & 0xffff; return l & 0xffff;
} }
unsigned int cpu_read_byte(unsigned int address) uint32_t cpu_read_byte(uint32_t address)
{ {
unsigned int l = cpu_read_long(address & ~3); uint32_t l = cpu_read_long(address & ~3);
l >>= 24 - (address & 3)*8; l >>= 24 - (address & 3)*8;
return l & 0xff; return l & 0xff;
} }
unsigned int cpu_read_word_dasm(unsigned int address) uint32_t cpu_read_word_dasm(uint32_t address)
{ {
return cpu_read_word(address); return cpu_read_word(address);
} }
unsigned int cpu_read_long_dasm(unsigned int address) uint32_t cpu_read_long_dasm(uint32_t address)
{ {
return cpu_read_long(address); return cpu_read_long(address);
} }
/* Write data to RAM or a device */ /* Write data to RAM or a device */
void cpu_write_byte(unsigned int address, unsigned int value) void cpu_write_byte(uint32_t address, uint32_t value)
{ {
WRITE_BYTE(g_ram, transform_address(address), value); WRITE_BYTE(g_ram, transform_address(address), value);
} }
void cpu_write_word(unsigned int address, unsigned int value) void cpu_write_word(uint32_t address, uint32_t value)
{ {
WRITE_WORD(g_ram, transform_address(address), value); WRITE_WORD(g_ram, transform_address(address), value);
} }
void cpu_write_long(unsigned int address, unsigned int value) void cpu_write_long(uint32_t address, uint32_t value)
{ {
WRITE_LONG(g_ram, transform_address(address), value); WRITE_LONG(g_ram, transform_address(address), value);
} }
/* Disassembler */ /* Disassembler */
void make_hex(char* buff, unsigned int pc, unsigned int length) void make_hex(char* buff, uint32_t pc, uint32_t length)
{ {
char* ptr = buff; char* ptr = buff;
@ -155,8 +164,8 @@ void make_hex(char* buff, unsigned int pc, unsigned int length)
void disassemble_program() void disassemble_program()
{ {
unsigned int pc; uint32_t pc;
unsigned int instr_size; uint32_t instr_size;
char buff[100]; char buff[100];
char buff2[100]; char buff2[100];
@ -174,7 +183,7 @@ void disassemble_program()
void cpu_instr_callback() void cpu_instr_callback()
{ {
unsigned int pc = m68k_get_reg(NULL, M68K_REG_PC); uint32_t pc = m68k_get_reg(NULL, M68K_REG_PC);
if (pc == 0xc) if (pc == 0xc)
exit_error("address exception"); exit_error("address exception");
@ -183,7 +192,7 @@ void cpu_instr_callback()
#if 0 #if 0
static char buff[100]; static char buff[100];
static char buff2[100]; static char buff2[100];
static unsigned int instr_size; static uint32_t instr_size;
instr_size = m68k_disassemble(buff, pc, M68K_CPU_TYPE_68020); instr_size = m68k_disassemble(buff, pc, M68K_CPU_TYPE_68020);
make_hex(buff2, pc, instr_size); make_hex(buff2, pc, instr_size);
@ -220,19 +229,19 @@ static void emulated_syscall(void)
case 4: /* write */ case 4: /* write */
{ {
unsigned int fd = m68k_get_reg(NULL, M68K_REG_D1); uint32_t fd = m68k_get_reg(NULL, M68K_REG_D1);
unsigned int ptr = m68k_get_reg(NULL, M68K_REG_D2); uint32_t ptr = m68k_get_reg(NULL, M68K_REG_D2);
unsigned int len = m68k_get_reg(NULL, M68K_REG_D3); uint32_t len = m68k_get_reg(NULL, M68K_REG_D3);
m68k_set_reg(M68K_REG_D0, write(fd, g_ram + transform_address(ptr), len)); m68k_set_reg(M68K_REG_D0, write(fd, g_ram + transform_address(ptr), len));
break; break;
} }
case 45: /* brk */ case 45: /* brk */
{ {
unsigned int newpos = m68k_get_reg(NULL, M68K_REG_D1); uint32_t newpos = m68k_get_reg(NULL, M68K_REG_D1);
if (newpos == 0) if (newpos == 0)
m68k_set_reg(M68K_REG_D0, brkpos); m68k_set_reg(M68K_REG_D0, brkpos);
else if ((newpos < BRK_BOTTOM) || (newpos >= BRK_TOP)) else if ((newpos < brkbase) || (newpos >= BRK_TOP))
m68k_set_reg(M68K_REG_D0, -ENOMEM); m68k_set_reg(M68K_REG_D0, -ENOMEM);
else else
{ {
@ -251,6 +260,37 @@ static void emulated_syscall(void)
} }
} }
static void load_program(FILE* fd)
{
fseek(fd, 0, SEEK_SET);
if (fread(g_ram, 1, 0x34, fd) != 0x34)
exit_error("couldn't read ELF header");
uint32_t phoff = READ_LONG(g_ram, 0x1c);
uint16_t phentsize = READ_WORD(g_ram, 0x2a);
uint16_t phnum = READ_WORD(g_ram, 0x2c);
entrypoint = READ_LONG(g_ram, 0x18);
if ((phentsize != 0x20) || (phnum != 1))
exit_error("unsupported ELF file");
fseek(fd, phoff, SEEK_SET);
if (fread(g_ram, 1, phentsize, fd) != phentsize)
exit_error("couldn't read program header");
uint32_t offset = READ_LONG(g_ram, 0x04);
uint32_t vaddr = READ_LONG(g_ram, 0x08);
uint32_t filesz = READ_LONG(g_ram, 0x10);
uint32_t memsz = READ_LONG(g_ram, 0x14);
brkbase = brkpos = vaddr + memsz;
uint32_t vaddroffset = transform_address(vaddr);
transform_address(vaddr + memsz); /* bounds check */
memset(g_ram+vaddroffset, 0, memsz);
fseek(fd, offset, SEEK_SET);
if (fread(g_ram+vaddroffset, 1, filesz, fd) != filesz)
exit_error("couldn't read program data");
}
/* The main loop */ /* The main loop */
int main(int argc, char* argv[]) int main(int argc, char* argv[])
{ {
@ -265,8 +305,7 @@ int main(int argc, char* argv[])
if((fhandle = fopen(argv[1], "rb")) == NULL) if((fhandle = fopen(argv[1], "rb")) == NULL)
exit_error("Unable to open %s", argv[1]); exit_error("Unable to open %s", argv[1]);
if(fread(g_ram, 1, RAM_TOP - RAM_BASE, fhandle) <= 0) load_program(fhandle);
exit_error("Error reading %s", argv[1]);
// disassemble_program(); // disassemble_program();
@ -287,9 +326,9 @@ int main(int argc, char* argv[])
*/ */
{ {
unsigned int sp = INIT_SP; uint32_t sp = INIT_SP;
cpu_write_long(sp -= 4, 0); cpu_write_long(sp -= 4, 0);
unsigned int envp = sp; uint32_t envp = sp;
cpu_write_long(sp -= 4, envp); cpu_write_long(sp -= 4, envp);
cpu_write_long(sp -= 4, 0); cpu_write_long(sp -= 4, 0);
unsigned long argv = sp; unsigned long argv = sp;