forked from Lephenixnoir/fxsdk
75 lines
1.8 KiB
C
75 lines
1.8 KiB
C
#include <fxos.h>
|
|
#include <errors.h>
|
|
#include <util.h>
|
|
#include <string.h>
|
|
|
|
/* asm_free_item(): Free an assembly instruction details */
|
|
static void asm_free_item(void *item)
|
|
{
|
|
struct asm_insn *insn = item;
|
|
free(insn->mnemonic);
|
|
free(insn->literal1);
|
|
free(insn->literal2);
|
|
}
|
|
|
|
/* asm_load(): Load an assembly table */
|
|
void asm_load(char const *file)
|
|
{
|
|
err_context("assembly", file, NULL);
|
|
if(!table_available())
|
|
{
|
|
err("too many tables, skipping");
|
|
err_pop();
|
|
return;
|
|
}
|
|
|
|
/* Map the file to memory */
|
|
int fd;
|
|
size_t size;
|
|
void *data = map(file, &fd, &size);
|
|
if(!data) { err_pop(); return; }
|
|
|
|
/* If the file is named "asm-x.txt", use "x" as the table name */
|
|
char *name = match_table_name(file, "asm", ".txt");
|
|
|
|
/* Parse the contents; the lexer in is [lexer-asm.l] and the parser is
|
|
implemented as an automaton with basic error correction. */
|
|
int count;
|
|
struct asm_insn *ins = lex_asm(data, size, &count);
|
|
|
|
table_create("asm", name, asm_free_item, count, sizeof *ins, ins);
|
|
|
|
unmap(data, fd, size);
|
|
err_pop();
|
|
}
|
|
|
|
/* Global storage for asm_match() */
|
|
static uint16_t asm_match_opcode;
|
|
|
|
/* asm_match(): Check if an instruction matches a pattern */
|
|
int asm_match(void *item)
|
|
{
|
|
struct asm_insn *insn = item;
|
|
return ((insn->bits ^ asm_match_opcode) & insn->arg_mask) == 0;
|
|
}
|
|
|
|
/* asm_decode(): Match a 16-bit opcode against the assembly database */
|
|
int asm_decode(uint16_t opcode, struct asm_match *match, int next)
|
|
{
|
|
asm_match_opcode = opcode;
|
|
char const *table;
|
|
struct asm_insn *insn = table_find("asm", asm_match, &table, next);
|
|
if(!insn) return 1;
|
|
|
|
/* Set match details */
|
|
match->insn = insn;
|
|
match->table = table;
|
|
|
|
match->n = (opcode >> insn->n_sh) & insn->n_mask;
|
|
match->m = (opcode >> insn->m_sh) & insn->m_mask;
|
|
match->d = (opcode >> insn->d_sh) & insn->d_mask;
|
|
match->i = (opcode >> insn->i_sh) & insn->i_mask;
|
|
|
|
return 0;
|
|
}
|