commit 4652c8227b187afe45d32ee1b25da0a350b70d32
parent cd2e08e52a768f6c1b8b8146fc7c9c16cb32f8d7
Author: Brian Swetland <swetland@frotz.net>
Date: Sun, 29 Jun 2025 15:51:40 -0700
sr32asm: cleanup, add la pseudoinstruction
- remove some dead code
- remove some debug chatter
- add/rename relocation types for _HILO
- implement "la" pseudo instruction
- handle symbles in "li" pseudo instruction
- implement "byte" directive
- ensure instructions get properly aligned after byte data
Diffstat:
1 file changed, 69 insertions(+), 37 deletions(-)
diff --git a/softrisc32/src/sr32asm.c b/softrisc32/src/sr32asm.c
@@ -16,11 +16,8 @@
#define SMAXSIZE 1024
static unsigned linenumber = 0;
-static char linestring[256];
static char *filename;
-FILE *ofp = 0;
-
void die(const char *fmt, ...) {
va_list ap;
fprintf(stderr,"\n%s:%d: ", filename, linenumber);
@@ -28,8 +25,6 @@ void die(const char *fmt, ...) {
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr,"\n");
- if (linestring[0])
- fprintf(stderr,"%s:%d: >> %s <<\n", filename, linenumber, linestring);
exit(1);
}
@@ -42,29 +37,38 @@ int is_signed21(uint32_t n) {
return ((n == 0) || (n == 0xFFFFF800));
}
-uint32_t image[1*1024*1024];
+uint8_t image[1*1024*1024];
uint32_t image_base = 0;
uint32_t image_size = 0;
uint32_t PC = 0;
void wr32(uint32_t addr, uint32_t val) {
+ addr &= ~3;
addr -= image_base;
if (addr < image_size) {
- image[addr >> 2] = val;
+ *((uint32_t*) (image + addr)) = val;
}
}
uint32_t rd32(uint32_t addr) {
+ addr &= ~3;
addr -= image_base;
if (addr < image_size) {
- return image[addr >> 2];
+ return *((uint32_t*) (image + addr));
}
return 0;
}
+void wr8(uint32_t addr, uint32_t val) {
+ addr -= image_base;
+ if (addr < image_size) {
+ image[addr] = val;
+ }
+}
#define TYPE_PCREL_S16 1
#define TYPE_PCREL_S21 2
#define TYPE_ABS_U32 3
-#define TYPE_LI_U32 4
+#define TYPE_ABS_HILO 4
+#define TYPE_PCREL_HILO 5
struct fixup {
struct fixup *next;
@@ -85,7 +89,6 @@ struct fixup *fixups;
uint32_t do_fixup(const char *name, uint32_t addr, uint32_t tgt, int type) {
uint32_t n = tgt;
- //fprintf(stderr,"FIXUP '%s' @%08x val=%08x typ=%d\n", name, addr, n, type);
switch(type) {
case TYPE_PCREL_S16:
n = n - (addr + 4);
@@ -100,14 +103,19 @@ uint32_t do_fixup(const char *name, uint32_t addr, uint32_t tgt, int type) {
case TYPE_ABS_U32:
wr32(addr, n);
break;
- case TYPE_LI_U32:
- wr32((addr + 0), rd32(addr + 0) | (n & 0xffff0000));
- wr32((addr + 4), rd32(addr + 4) | (n & 0x0000ffff) << 16);
+ case TYPE_PCREL_HILO:
+ n = n - (addr + 4);
+ case TYPE_ABS_HILO:
+ uint32_t hi = n >> 16;
+ uint32_t lo = n & 0xffff;
+ if (lo & 0x8000) hi += 1;
+ n = (hi << 16) | lo;
+ wr32(addr + 0, rd32(addr + 0) | (hi << 16));
+ wr32(addr + 4, rd32(addr + 4) | (lo << 16));
break;
default:
die("unknown branch type %d\n", type);
}
- //fprintf(stderr,"FIXUP %08x (%d)\n", n, n);
return n;
oops:
die("label '%s' at %08x is out of range of %08x\n", name, tgt, addr);
@@ -187,7 +195,10 @@ void checklabels(void) {
void sr32dis(uint32_t pc, uint32_t ins, char *out);
void emit(uint32_t instr) {
- //fprintf(stderr,"{%08x:%08x} ", PC,instr);
+ if (PC & 3) {
+ PC = (PC + 3) & ~3;
+ }
+ //fprintf(stderr,"{%08x:%08x} ", PC, instr);
wr32(PC, instr);
PC += 4;
}
@@ -228,7 +239,7 @@ enum tokens {
tLDW, tLDH, tLDB, tLDX, tLUI, tLDHU, tLDBU, tAUIPC,
tSTW, tSTH, tSTB, tSTX,
tJAL, tSYSCALL, tBREAK, tSYSRET,
- tNOP, tMV, tLI, tJ, tJR, tRET,
+ tNOP, tMV, tLI, tLA, tJ, tJR, tRET,
tEQU, tBYTE, tHALF, tWORD,
NUMTOKENS,
};
@@ -244,7 +255,7 @@ char *tnames[] = { "<EOF>", "<EOL>", "IDENT", "REGISTER", "NUMBER", "STRING",
"LDW", "LDH", "LDB", "LDX", "LUI", "LDHU", "LDBU", "AUIPC",
"STW", "STH", "STB", "STX",
"JAL", "SYSCALL", "BREAK", "SYSRET",
- "NOP", "MV", "LI", "J", "JR", "RET",
+ "NOP", "MV", "LI", "LA", "J", "JR", "RET",
"EQU", "BYTE", "HALF", "WORD",
};
@@ -357,7 +368,7 @@ unsigned tokenize(State *state) {
}
*s++ = 0;
state->str = sbuf;
- return tIDENT;
+ return tSTRING;
}
*s++ = x;
while (!is_stopchar(x = nextchar(state))) {
@@ -427,7 +438,6 @@ void expect(State *s, unsigned expected) {
die("expected %s, got %s", tnames[expected], tnames[s->tok]);
}
}
-
void require(State *s, unsigned expected) {
expect(s, expected);
next(s);
@@ -438,13 +448,11 @@ void parse_reg(State *s, uint32_t *r) {
*r = s->num;
next(s);
}
-
void parse_num(State *s, uint32_t *n) {
expect(s, tNUMBER);
*n = s->num;
next(s);
}
-
void parse_memref(State *s, uint32_t *r, uint32_t *i) {
if (s->tok == tNUMBER) {
*i = s->num;
@@ -459,7 +467,6 @@ void parse_memref(State *s, uint32_t *r, uint32_t *i) {
parse_reg(s, r);
require(s, tCPAREN);
}
-
void parse_rel(State *s, unsigned type, uint32_t *i) {
switch (s->tok) {
case tIDENT:
@@ -588,20 +595,27 @@ int parse_line(State *s) {
break;
case tLI:
parse_r_c(s, &t);
- parse_num(s, &i);
- if (is_signed16(i)) {
- emit(ins_i(i, 0, t, IR_ADD));
+ if (s->tok == tIDENT) {
+ parse_rel(s, TYPE_ABS_HILO, &i);
} else {
- uint32_t hi = i >> 16;
- if (i & 0x8000) {
- hi += 1;
- }
- emit(ins_l(hi, 0, t, L_LUI));
- if (i & 0xFFFF) {
- emit(ins_i(i & 0xFFFF, t, t, IR_ADD));
+ parse_num(s, &i);
+ if (is_signed16(i)) {
+ emit(ins_i(i, 0, t, IR_ADD));
+ } else {
+ uint32_t hi = i >> 16;
+ uint32_t lo = i & 0xffff;
+ if (lo & 0x8000) hi += 1;
+ emit(ins_l(hi, 0, t, L_LUI));
+ emit(ins_i(lo, t, t, IR_ADD));
}
}
break;
+ case tLA:
+ parse_r_c(s, &t);
+ parse_rel(s, TYPE_PCREL_HILO, &i);
+ emit(ins_l(i >> 16, 0, t, L_AUIPC));
+ emit(ins_i(i & 0xFFFF, t, t, IR_ADD));
+ break;
case tJ:
parse_rel(s, TYPE_PCREL_S21, &i);
emit(ins_j(i, 0, J_JAL));
@@ -612,7 +626,6 @@ int parse_line(State *s) {
parse_num(s, &i);
setlabel(name, i);
break;
-
case tWORD:
for (;;) {
switch (s->tok) {
@@ -630,8 +643,26 @@ int parse_line(State *s) {
next(s);
}
break;
+ case tBYTE:
+ for (;;) {
+ switch (s->tok) {
+ case tNUMBER:
+ wr8(PC++, s->num);
+ break;
+ case tSTRING:
+ for (char *p = s->str; *p != 0; p++) {
+ wr8(PC++, *p);
+ }
+ break;
+ default:
+ die("expected numeric or string data");
+ }
+ if (next(s) != tCOMMA) break;
+ next(s);
+ }
+ break;
- // todo: BYTE, HALF, string data
+ // todo: HALF
case tEOL:
return 1;
case tEOF:
@@ -663,13 +694,14 @@ int main(int argc, char **argv) {
image_size = sizeof(image);
PC = image_base;
- if (argc < 2)
+ if (argc < 2) {
die("no file specified");
- if (argc == 3)
+ }
+ if (argc == 3) {
outname = argv[2];
+ }
assemble(filename);
- linestring[0] = 0;
checklabels();
save(outname);
return 0;
