summaryrefslogtreecommitdiff
path: root/libinterp/das-thumb.c
diff options
context:
space:
mode:
Diffstat (limited to 'libinterp/das-thumb.c')
-rw-r--r--libinterp/das-thumb.c548
1 files changed, 548 insertions, 0 deletions
diff --git a/libinterp/das-thumb.c b/libinterp/das-thumb.c
new file mode 100644
index 00000000..2609bbe5
--- /dev/null
+++ b/libinterp/das-thumb.c
@@ -0,0 +1,548 @@
+#include <lib9.h>
+
+typedef struct Instr Instr;
+struct Instr
+{
+ ulong w;
+ ulong addr;
+ uchar op; /* super opcode */
+
+ uchar rd;
+ uchar rn;
+ uchar rs;
+
+ long imm; /* imm */
+ char* curr; /* fill point in buffer */
+ char* end; /* end of buffer */
+ char* err; /* error message */
+};
+
+typedef struct Opcode Opcode;
+struct Opcode
+{
+ char* o;
+ void (*f)(Opcode*, Instr*);
+ int unused; /* remove field some time */
+ char* a;
+};
+
+static void format(char*, Instr*, char*);
+static int thumbinst(ulong, char, char*, int);
+static int thumbdas(ulong, char*, int);
+
+static
+char* cond[16] =
+{
+ "EQ", "NE", "CS", "CC",
+ "MI", "PL", "VS", "VC",
+ "HI", "LS", "GE", "LT",
+ "GT", "LE", 0, "NV"
+};
+
+static int
+get4(ulong addr, long *v)
+{
+ *v = *(ulong*)addr;
+ return 1;
+}
+
+static int
+get2(ulong addr, ushort *v)
+{
+ *v = *(ushort*)addr;
+ return 1;
+}
+
+static char *
+_hexify(char *buf, ulong p, int zeros)
+{
+ ulong d;
+
+ d = p/16;
+ if(d)
+ buf = _hexify(buf, d, zeros-1);
+ else
+ while(zeros--)
+ *buf++ = '0';
+ *buf++ = "0123456789abcdef"[p&0x0f];
+ return buf;
+}
+
+#define B(h, l) bits(ins, h, l)
+
+static int
+bits(int i, int h, int l)
+{
+ if(h < l)
+ print("h < l in bits");
+ return (i&(((1<<(h-l+1))-1)<<l))>>l;
+}
+
+int
+thumbclass(long w)
+{
+ int o;
+ int ins = w;
+
+ if(ins&0xffff0000)
+ return 3+2+2+4+16+4+1+8+6+2+2+2+4+1+1+1+2;
+ o = B(15, 13);
+ switch(o){
+ case 0:
+ o = B(12, 11);
+ switch(o){
+ case 0:
+ case 1:
+ case 2:
+ return B(12, 11);
+ case 3:
+ if(B(10, 10) == 0)
+ return 3+B(9, 9);
+ else
+ return 3+2+B(9, 9);
+ }
+ case 1:
+ return 3+2+2+B(12, 11);
+ case 2:
+ o = B(12, 10);
+ if(o == 0)
+ return 3+2+2+4+B(9, 6);
+ if(o == 1){
+ o = B(9, 8);
+ if(o == 3)
+ return 3+2+2+4+16+B(9, 8);
+ return 3+2+2+4+16+B(9, 8);
+ }
+ if(o == 2 || o == 3)
+ return 3+2+2+4+16+4;
+ return 3+2+2+4+16+4+1+B(11, 9);
+ case 3:
+ return 3+2+2+4+16+4+1+8+B(12, 11);
+ case 4:
+ if(B(12, 12) == 0)
+ return 3+2+2+4+16+4+1+8+4+B(11, 11);
+ return 3+2+2+4+16+4+1+8+6+B(11, 11);
+ case 5:
+ if(B(12, 12) == 0)
+ return 3+2+2+4+16+4+1+8+6+2+B(11, 11);
+ if(B(11, 8) == 0)
+ return 3+2+2+4+16+4+1+8+6+2+2+B(7, 7);
+ return 3+2+2+4+16+4+1+8+6+2+2+2+B(11, 11);
+ case 6:
+ if(B(12, 12) == 0)
+ return 3+2+2+4+16+4+1+8+6+2+2+2+2+B(11, 11);
+ if(B(11, 8) == 0xf)
+ return 3+2+2+4+16+4+1+8+6+2+2+2+4;
+ return 3+2+2+4+16+4+1+8+6+2+2+2+4+1;
+ case 7:
+ o = B(12, 11);
+ switch(o){
+ case 0:
+ return 3+2+2+4+16+4+1+8+6+2+2+2+4+1+1;
+ case 1:
+ return 3+2+2+4+16+4+1+8+6+2+2+2+4+1+1+1+2;
+ case 2:
+ return 3+2+2+4+16+4+1+8+6+2+2+2+4+1+1+1;
+ case 3:
+ return 3+2+2+4+16+4+1+8+6+2+2+2+4+1+1+1+1;
+ }
+ }
+}
+
+static int
+decode(ulong pc, Instr *i)
+{
+ ushort w;
+
+ get2(pc, &w);
+ i->w = w;
+ i->addr = pc;
+ i->op = thumbclass(w);
+ return 1;
+}
+
+static void
+bprint(Instr *i, char *fmt, ...)
+{
+ va_list arg;
+
+ va_start(arg, fmt);
+ i->curr = vseprint(i->curr, i->end, fmt, arg);
+ va_end(arg);
+}
+
+static void
+thumbshift(Opcode *o, Instr *i)
+{
+ int ins = i->w;
+
+ i->rd = B(2, 0);
+ i->rn = B(5, 3);
+ i->imm = B(10, 6);
+ format(o->o, i, o->a);
+}
+
+static void
+thumbrrr(Opcode *o, Instr *i)
+{
+ int ins = i->w;
+
+ i->rd = B(2, 0);
+ i->rn = B(5, 3);
+ i->rs = B(8, 6);
+ format(o->o, i, o->a);
+}
+
+static void
+thumbirr(Opcode *o, Instr *i)
+{
+ int ins = i->w;
+
+ i->rd = B(2, 0);
+ i->rn = B(5, 3);
+ i->imm = B(8, 6);
+ format(o->o, i, o->a);
+}
+
+static void
+thumbir(Opcode *o, Instr *i)
+{
+ int ins = i->w;
+
+ i->rd = B(10, 8);
+ i->imm = B(7, 0);
+ format(o->o, i, o->a);
+}
+
+static void
+thumbrr(Opcode *o, Instr *i)
+{
+ int ins = i->w;
+
+ i->rd = B(2, 0);
+ i->rn = B(5, 3);
+ format(o->o, i, o->a);
+}
+
+static void
+thumbrrh(Opcode *o, Instr *i)
+{
+ int ins = i->w;
+
+ i->rd = B(2, 0);
+ i->rn = B(5, 3);
+ if(B(6, 6))
+ i->rn += 8;
+ if(B(7, 7))
+ i->rd += 8;
+ if(o != nil){
+ if(i->w == 0x46b7 || i->w == 0x46f7 || i->w == 0x4730 || i->w == 0x4770) // mov r6, pc or mov lr, pc or bx r6 or bx lr
+ format("RET", i, "");
+ else
+ format(o->o, i, o->a);
+ }
+}
+
+static void
+thumbpcrel(Opcode *o, Instr *i)
+{
+ int ins = i->w;
+
+ i->rn = 15;
+ i->rd = B(10, 8);
+ i->imm = 4*(B(7, 0)+1);
+ if(i->addr & 3)
+ i->imm -= 2;
+ format(o->o, i, o->a);
+}
+
+static void
+thumbmovirr(Opcode *o, Instr *i)
+{
+ int ins = i->w;
+
+ i->rd = B(2, 0);
+ i->rn = B(5, 3);
+ i->imm = B(10, 6);
+ if(strcmp(o->o, "MOVW") == 0)
+ i->imm *= 4;
+ else if(strncmp(o->o, "MOVH", 4) == 0)
+ i->imm *= 2;
+ format(o->o, i, o->a);
+}
+
+static void
+thumbmovsp(Opcode *o, Instr *i)
+{
+ int ins = i->w;
+
+ i->rn = 13;
+ i->rd = B(10, 8);
+ i->imm = 4*B(7, 0);
+ format(o->o, i, o->a);
+}
+
+static void
+thumbaddsppc(Opcode *o, Instr *i)
+{
+ int ins = i->w;
+
+ i->rd = B(10, 8);
+ i->imm = 4*B(7, 0);
+ if(i->op == 48)
+ i->imm += 4;
+ format(o->o, i, o->a);
+}
+
+static void
+thumbaddsp(Opcode *o, Instr *i)
+{
+ int ins = i->w;
+
+ i->imm = 4*B(6, 0);
+ format(o->o, i, o->a);
+}
+
+static void
+thumbswi(Opcode *o, Instr *i)
+{
+ int ins = i->w;
+
+ i->imm = B(7, 0);
+ format(o->o, i, o->a);
+}
+
+static void
+thumbbcc(Opcode *o, Instr *i)
+{
+ int off, ins = i->w;
+
+ off = B(7, 0);
+ if(off & 0x80)
+ off |= 0xffffff00;
+ i->imm = i->addr + 2*off + 4;
+ if(o != nil)
+ format(o->o, i, o->a);
+}
+
+static void
+thumbb(Opcode *o, Instr *i)
+{
+ int off, ins = i->w;
+
+ off = B(10, 0);
+ if(off & 0x400)
+ off |= 0xfffff800;
+ i->imm = i->addr + 2*off + 4;
+ if(o != nil)
+ format(o->o, i, o->a);
+}
+
+static void
+thumbbl(Opcode *o, Instr *i)
+{
+ int off, h, ins = i->w;
+ static int reglink;
+
+ h = B(11, 11);
+ off = B(10, 0);
+ if(h == 0){
+ if(off & 0x400)
+ off |= 0xfffff800;
+ i->imm = i->addr + (off<<12) + 4;
+ reglink = i->imm;
+ }
+ else{
+ i->imm = reglink + 2*off;
+ }
+ if(o != nil)
+ format(o->o, i, o->a);
+}
+
+static void
+thumbregs(Opcode *o, Instr *i)
+{
+ int ins = i->w;
+
+ if(i->op == 52 || i->op == 53)
+ i->rd = 13;
+ else
+ i->rd = B(10, 8);
+ i->imm = B(7, 0);
+ format(o->o, i, o->a);
+}
+
+static void
+thumbunk(Opcode *o, Instr *i)
+{
+ format(o->o, i, o->a);
+}
+
+static Opcode opcodes[] =
+{
+ "LSL", thumbshift, 0, "$#%i,R%n,R%d", // 0
+ "LSR", thumbshift, 0, "$#%i,R%n,R%d", // 1
+ "ASR", thumbshift, 0, "$#%i,R%n,R%d", // 2
+ "ADD", thumbrrr, 0, "R%s,R%n,R%d", // 3
+ "SUB", thumbrrr, 0, "R%s,R%n,R%d", // 4
+ "ADD", thumbirr, 0, "$#%i,R%n,R%d", // 5
+ "SUB", thumbirr, 0, "$#%i,R%n,R%d", // 6
+ "MOVW", thumbir, 0, "$#%i,R%d", // 7
+ "CMP", thumbir, 0, "$#%i,R%d", // 8
+ "ADD", thumbir, 0, "$#%i,R%d,R%d", // 9
+ "SUB", thumbir, 0, "$#%i,R%d,R%d", // 10
+ "AND", thumbrr, 0, "R%n,R%d,R%d", // 11
+ "EOR", thumbrr, 0, "R%n,R%d,R%d", // 12
+ "LSL", thumbrr, 0, "R%n,R%d,R%d", // 13
+ "LSR", thumbrr, 0, "R%n,R%d,R%d", // 14
+ "ASR", thumbrr, 0, "R%n,R%d,R%d", // 15
+ "ADC", thumbrr, 0, "R%n,R%d,R%d", // 16
+ "SBC", thumbrr, 0, "R%n,R%d,R%d", // 17
+ "ROR", thumbrr, 0, "R%n,R%d,R%d", // 18
+ "TST", thumbrr, 0, "R%n,R%d", // 19
+ "NEG", thumbrr, 0, "R%n,R%d", // 20
+ "CMP", thumbrr, 0, "R%n,R%d", // 21
+ "CMPN", thumbrr, 0, "R%n,R%d", // 22
+ "OR", thumbrr, 0, "R%n,R%d,R%d", // 23
+ "MUL", thumbrr, 0, "R%n,R%d,R%d", // 24
+ "BITC", thumbrr, 0, "R%n,R%d,R%d", // 25
+ "MOVN", thumbrr, 0, "R%n,R%d", // 26
+ "ADD", thumbrrh, 0, "R%n,R%d,R%d", // 27
+ "CMP", thumbrrh, 0, "R%n,R%d", // 28
+ "MOVW", thumbrrh, 0, "R%n,R%d", // 29
+ "BX", thumbrrh, 0, "R%n", // 30
+ "MOVW", thumbpcrel, 0, "%i(PC),R%d", // 31
+ "MOVW", thumbrrr, 0, "R%d, [R%s,R%n]", // 32
+ "MOVH", thumbrrr, 0, "R%d, [R%s,R%n]", // 33
+ "MOVB", thumbrrr, 0, "R%d, [R%s,R%n]", // 34
+ "MOVB", thumbrrr, 0, "[R%s,R%n],R%d", // 35
+ "MOVW", thumbrrr, 0, "[R%s,R%n],R%d", // 36
+ "MOVHU", thumbrrr, 0, "[R%s,R%n],R%d", // 37
+ "MOVBU", thumbrrr, 0, "[R%s,R%n],R%d", // 38
+ "MOVH", thumbrrr, 0, "[R%s,R%n],R%d", // 39
+ "MOVW", thumbmovirr, 0, "R%d,%i(R%n)", // 40
+ "MOVW", thumbmovirr, 0, "%i(R%n),R%d", // 41
+ "MOVB", thumbmovirr, 0, "R%d,%i(R%n)", // 42
+ "MOVBU", thumbmovirr, 0, "%i(R%n),R%d", // 43
+ "MOVH", thumbmovirr, 0, "R%d,%i(R%n)", // 44
+ "MOVHU", thumbmovirr, 0, "%i(R%n),R%d", // 45
+ "MOVW", thumbmovsp, 0, "R%d,%i(SP)", // 46
+ "MOVW", thumbmovsp, 0, "%i(SP),R%d", // 47
+ "ADD", thumbaddsppc,0, "$#%i,PC,R%d", // 48
+ "ADD", thumbaddsppc,0, "$#%i,SP,R%d", // 49
+ "ADD", thumbaddsp, 0, "$#%i,SP,SP", // 50
+ "SUB", thumbaddsp, 0, "$#%i,SP,SP", // 51
+ "PUSH", thumbregs, 0, "R%d, %r", // 52
+ "POP", thumbregs, 0, "R%d, %r", // 53
+ "STMIA", thumbregs, 0, "R%d, %r", // 54
+ "LDMIA", thumbregs, 0, "R%d, %r", // 55
+ "SWI", thumbswi, 0, "$#%i", // 56
+ "B%c", thumbbcc, 0, "%b", // 57
+ "B", thumbb, 0, "%b", // 58
+ "BL", thumbbl, 0, "", // 59
+ "BL", thumbbl, 0, "%b", // 60
+ "UNK", thumbunk, 0, "", // 61
+};
+
+static void
+format(char *mnemonic, Instr *i, char *f)
+{
+ int j, k, m, n;
+ int ins = i->w;
+
+ if(mnemonic)
+ format(0, i, mnemonic);
+ if(f == 0)
+ return;
+ if(mnemonic)
+ if(i->curr < i->end)
+ *i->curr++ = '\t';
+ for ( ; *f && i->curr < i->end; f++) {
+ if(*f != '%') {
+ *i->curr++ = *f;
+ continue;
+ }
+ switch (*++f) {
+
+ case 'c': /* Bcc */
+ bprint(i, "%s", cond[B(11, 8)]);
+ break;
+
+ case 's':
+ bprint(i, "%d", i->rs);
+ break;
+
+ case 'n':
+ bprint(i, "%d", i->rn);
+ break;
+
+ case 'd':
+ bprint(i, "%d", i->rd);
+ break;
+
+ case 'i':
+ bprint(i, "%lux", i->imm);
+ break;
+
+ case 'b':
+ bprint(i, "%lux", i->imm);
+ break;
+
+ case 'r':
+ n = i->imm&0xff;
+ j = 0;
+ k = 0;
+ while(n) {
+ m = j;
+ while(n&0x1) {
+ j++;
+ n >>= 1;
+ }
+ if(j != m) {
+ if(k)
+ bprint(i, ",");
+ if(j == m+1)
+ bprint(i, "R%d", m);
+ else
+ bprint(i, "R%d-R%d", m, j-1);
+ k = 1;
+ }
+ j++;
+ n >>= 1;
+ }
+ break;
+
+ case '\0':
+ *i->curr++ = '%';
+ return;
+
+ default:
+ bprint(i, "%%%c", *f);
+ break;
+ }
+ }
+ *i->curr = 0;
+}
+
+void
+das(ulong *x, int n)
+{
+ ulong pc;
+ Instr i;
+ char buf[128];
+
+ pc = (ulong)x;
+ while(n > 0) {
+ i.curr = buf;
+ i.end = buf+sizeof(buf)-1;
+
+ if(decode(pc, &i) < 0)
+ sprint(buf, "???");
+ else
+ (*opcodes[i.op].f)(&opcodes[i.op], &i);
+
+ print("%.8lux %.8lux\t%s\n", pc, i.w, buf);
+ pc += 2;
+ n--;
+ }
+}
generated by cgit v1.2.3 (git 2.46.0) at 2025-12-10 12:20:56 +0000