oreodave/aal
Archived
Public Access
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Use conversion functions for (h)word to and from bytes instead of bit shifting

Browse Source 
Wasn't very secure for endianness, and using these helpers abstracts
the details away a bit in case I want to enforce a certain system.
This commit is contained in:
Aryadev Chavali
2023-10-22 20:29:02 +01:00
parent aa3d1cb85f
commit 073a23152e
2 changed files with 33 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

51
src/runtime.c
View File

@@ -63,7 +63,7 @@ void vm_execute(vm_t *vm)
else if (OPCODE_IS_TYPE(instruction.opcode, OP_MOV))
{
data_t d =
MOV_ROUTINES[instruction.opcode](vm, instruction.operand.as_word);
MOV_ROUTINES[instruction.opcode](vm, instruction.operand.as_byte);
vm->registers.ret = d.as_word;
prog->ptr++;
}
@@ -274,30 +274,32 @@ data_t vm_peek(vm_t *vm, data_type_t type)
return DBYTE(0);
return DBYTE(vm->stack.data[vm->stack.ptr - 1]);
break;
case DATA_TYPE_HWORD:
case DATA_TYPE_HWORD: {
if (vm->stack.ptr < HWORD_SIZE)
// TODO: Error STACK_UNDERFLOW
return DHWORD(0);
hword h = 0;
byte bytes[HWORD_SIZE] = {0};
for (size_t i = 0; i < HWORD_SIZE; ++i)
{
byte b = vm->stack.data[vm->stack.ptr - 1 - i];
h = h | (((word)b) << (i * 8));
byte b = vm->stack.data[vm->stack.ptr - i - 1];
bytes[HWORD_SIZE - 1 - i] = b;
}
return DWORD(h);
return DWORD(convert_bytes_to_hword(bytes));
break;
case DATA_TYPE_WORD:
}
case DATA_TYPE_WORD: {
if (vm->stack.ptr < WORD_SIZE)
// TODO: Error STACK_UNDERFLOW
return DWORD(0);
word w = 0;
byte bytes[WORD_SIZE] = {0};
for (size_t i = 0; i < WORD_SIZE; ++i)
{
byte b = vm->stack.data[vm->stack.ptr - 1 - i];
w = w | (((word)b) << (i * 8));
byte b = vm->stack.data[vm->stack.ptr - i - 1];
bytes[WORD_SIZE - 1 - i] = b;
}
return DWORD(w);
return DWORD(convert_bytes_to_hword(bytes));
break;
}
default:
return DBYTE(0);
break;
@@ -317,10 +319,11 @@ void vm_push_hword(vm_t *vm, data_t f)
if (vm->stack.ptr + HWORD_SIZE >= vm->stack.max)
// TODO: Error STACK_OVERFLOW
return;
for (size_t i = 32; i > 0; i -= 8)
byte bytes[HWORD_SIZE] = {0};
convert_hword_to_bytes(f.as_hword, bytes);
for (size_t i = 0; i < HWORD_SIZE; ++i)
{
const word mask = ((word)0b11111111) << (i - 8);
byte b = (f.as_hword & mask) >> (i - 8);
byte b = bytes[HWORD_SIZE - i - 1];
vm_push_byte(vm, DBYTE(b));
}
}
@@ -330,11 +333,11 @@ void vm_push_word(vm_t *vm, data_t w)
if (vm->stack.ptr + WORD_SIZE >= vm->stack.max)
// TODO: Error STACK_OVERFLOW
return;
// By default store in big endian
for (size_t i = 64; i > 0; i -= 8)
byte bytes[WORD_SIZE] = {0};
convert_word_to_bytes(w.as_word, bytes);
for (size_t i = 0; i < WORD_SIZE; ++i)
{
const word mask = ((word)0b11111111) << (i - 8);
byte b = (w.as_word & mask) >> (i - 8);
byte b = bytes[WORD_SIZE - i - 1];
vm_push_byte(vm, DBYTE(b));
}
}
@@ -436,13 +439,13 @@ data_t vm_pop_hword(vm_t *vm)
if (vm->stack.ptr < HWORD_SIZE)
// TODO: Error STACK_UNDERFLOW
return DHWORD(0);
hword h = 0;
byte bytes[HWORD_SIZE] = {0};
for (size_t i = 0; i < HWORD_SIZE; ++i)
{
data_t b = vm_pop_byte(vm);
h = h | ((word)(b.as_byte) << (i * 8));
bytes[HWORD_SIZE - 1 - i] = b.as_byte;
}
return DWORD(h);
return DWORD(convert_bytes_to_hword(bytes));
}
data_t vm_pop_word(vm_t *vm)
@@ -450,13 +453,13 @@ data_t vm_pop_word(vm_t *vm)
if (vm->stack.ptr < WORD_SIZE)
// TODO: Error STACK_UNDERFLOW
return DWORD(0);
word w = 0;
byte bytes[WORD_SIZE] = {0};
for (size_t i = 0; i < WORD_SIZE; ++i)
{
data_t b = vm_pop_byte(vm);
w = w | ((word)(b.as_byte) << (i * 8));
bytes[WORD_SIZE - 1 - i] = b.as_byte;
}
return DWORD(w);
return DWORD(convert_bytes_to_word(bytes));
}
void vm_not_byte(vm_t *vm)

7
src/runtime.h
View File

@@ -83,6 +83,10 @@ static const push_reg_f PUSH_REG_ROUTINES[] = {
[OP_PUSH_REGISTER_WORD] = vm_push_word_register,
};
data_t vm_pop_byte(vm_t *);
data_t vm_pop_hword(vm_t *);
data_t vm_pop_word(vm_t *);
data_t vm_mov_byte(vm_t *, byte);
data_t vm_mov_hword(vm_t *, byte);
data_t vm_mov_word(vm_t *, byte);
@@ -94,9 +98,6 @@ static const mov_f MOV_ROUTINES[] = {
[OP_MOV_WORD] = vm_mov_word,
};
data_t vm_pop_byte(vm_t *);
data_t vm_pop_hword(vm_t *);
data_t vm_pop_word(vm_t *);
void vm_not_byte(vm_t *);
void vm_not_hword(vm_t *);