stuff

Makefile

@@ -6,7 +6,7 @@ all: k.exe
 src = instr/instrs.c karch/decd.c karch/main.c karch/regs.c
 obj = $(patsubst %.c,%.o,$(src))
 
-%.o: %.c instrs/i_arch.h */*.h
+%.o: %.c instrs/i_arch.h */*.h */*.c
 	@gcc -O2 -Wall -I./karch -c $< -o $@
 
 instrs/i_arch.h: instr/INSTRS instr/instrs.py

instr/INSTRS

@@ -1,6 +1,8 @@
 # The OS/K Team licences this file to you under the MIT license.
 # See the LICENSE file in the project root for more information.
 
+nop
+
 add r r
 add r i
 add r m

instr/instrs.c

@@ -3,6 +3,11 @@
 
 #include "instrs.h"
 
+IMPL_START_0(nop)
+{
+}
+IMPL_END;
+
 IMPL_START_2(add)
 {
     v1 += v2;

instr/instrs.py

@@ -53,7 +53,7 @@ for _, line in enumerate(fi):
     hd.write("#define I_{} {}\n".format(name.upper(), count))
     hd.write("#ifdef _NEED_ARCH_I\n")
     hd.write('{{ "{}", "{}", {}, {}, i_{} }},\n'\
-                .format(tok[0], name, p1, p2, tok[0]))
+                .format(tok[0].strip(), name, p1, p2, tok[0]))
     hd.write("#endif\n\n")
 
     count = count + 1

karch/arch.h

@@ -1,14 +1,18 @@
 // The OS/K Team licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-#include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <stdarg.h>
 
 #define log printf
+#define vlog vprintf
 
 #define packed __attribute__ ((__packed__))
 #define static_assert _Static_assert
+#define alignof _Alignof
 
 typedef unsigned int        bool;
 typedef unsigned char       uchar;
@@ -28,7 +32,7 @@ enum
     R08, R09, R10, R11, R12, R13, R14, R15,
     K00, K01, K02, K03, K04, K05, K06, K07,
     CR0, CR1, CR2, CR3, CR4, CR5, CR6, CR7,
-    RIP, FLG,
+    RIP, FLG, RET,
 
     NREGS
 };
@@ -83,7 +87,7 @@ struct ctx_t
     instr_t *i;
 
     // Memory and memory size
-    uchar  *mp;
+    ushort *mp;
     ulong   mz;
 
     // Read next instruction
@@ -92,24 +96,61 @@ struct ctx_t
 
 enum
 {
-    E_ILL,          // Ill-formed
+    E_SHT,          // Shutdown instruction
     E_IMP,          // Not implemented
+    E_ILL,          // Ill-formed
     E_ACC,          // Invalid access
     E_SYS,          // Supervisor only
-    E_SHT,          // Shutdown instruction
+    E_ALI,          // Alignment error
     NEXCPTS
 };
 
 void dumpregs(ctx_t *ctx);
 
-static inline void _except(ctx_t *ctx, int code, char *str)
+static inline void _except(ctx_t *ctx, int code, char *fmt, ...)
 {
-    log("\nException %d - %s\n", code, str);
+    va_list ap;
+
+    log("\nException %d - ", code);
+    
+    va_start(ap, fmt);
+    vlog(fmt, ap);
+    va_end(ap);
+    
+    log("\n");
+
     dumpregs(ctx);
-    exit(code);
+    free(ctx->mp);
+    exit(code+1);
 }
 
 void decode(ctx_t *ctx);
 
+#define MEMOFF (1 * 1024 * 1024)
+#define MEMSIZE (16 * 1024 * 1024)  // 16MB
+
+#define addr2real(p) ((p) - MEMOFF)
+#define real2addr(p) ((p) + MEMOFF)
+
+static inline ulong readmem64(ctx_t *ctx, ulong addr)
+{
+    ulong real = addr2real(addr);
+
+    if (addr % alignof(ulong) > 0) {
+        _except(ctx, E_ALI, "Non-aligned memory access");
+    }
+
+    if (addr < MEMOFF || real >= MEMSIZE) {
+        _except(ctx, E_ACC, "Accessing inexistent memory");
+    }
+
+    ulong val = (ulong)ctx->mp[real++];
+    val = (val << 16) | (ulong)ctx->mp[real++];
+    val = (val << 16) | (ulong)ctx->mp[real++];
+    val = (val << 16) | (ulong)ctx->mp[real++];
+    
+    return val;
+}
+
 #include "../instr/arch_i.h"
 

karch/decd.c

@@ -63,11 +63,11 @@ void dumpregs(ctx_t *ctx)
     log("\n");
 }
 
-void dumpinstr(ctx_t *ctx, ushort c, acc_t *p1, acc_t *p2)
+void dumpinstr(ctx_t *ctx, ulong rip, ushort c, acc_t *p1, acc_t *p2)
 {
     acc_t *p = 0;
     instr_t *i = &ctx->i[c];
-    log("%s", i->name);
+    log("0x%016lX: %s", rip, i->name);
     
     if (i->prm1 != NOPRM)
         p = p1;
@@ -96,6 +96,7 @@ void decode(ctx_t *ctx)
     instr_t *i;
     acc_t p1 = { 0 }, p2 = { 0 };
 
+    ulong rip = ctx->r[RIP].val;
     ushort c = ctx->get(ctx);
     
     if (c == 0xFFFF) {
@@ -107,7 +108,7 @@ void decode(ctx_t *ctx)
     }
     
     else if (!ISINSTR(c)) {
-        _except(ctx, E_ILL, "Bad opcode");
+        _except(ctx, E_ILL, "Bad opcode 0x%4hX", c);
     }
 
     // Scanning an instruction
@@ -122,7 +123,7 @@ void decode(ctx_t *ctx)
         }
     }
     
-    dumpinstr(ctx, c, &p1, &p2);
+    dumpinstr(ctx, rip, c, &p1, &p2);
     i->func(ctx, &p1, &p2);
 }
 

karch/main.c

@@ -3,7 +3,7 @@
 
 #include "arch.h"
 
-ushort prog[] = {
+ushort fwprog[] = {
     I_ADD_R_I, RDX, A_IMM32, 0xAABB, 0xCCDD,
     I_MOV_R_R, RAX, RDX,
     I_MOV_R_I, RBX, A_IMM64, 0x7777, 0x6666, 0x5555, 0x4444,
@@ -15,13 +15,15 @@ ushort prog[] = {
 
 ushort bget(ctx_t *ctx)
 {
-    static int i = 0;
-
-    if (i >= sizeof(prog)/sizeof(ushort)) {
-        _except(ctx, E_ACC, "End of text");
+    if (addr2real(ctx->r[RIP].val) >= MEMSIZE) {
+        _except(ctx, E_ACC, "Executing out of memory");
     }
     
-    return prog[i++];
+    ushort c = ctx->mp[addr2real(ctx->r[RIP].val)];
+    
+    ctx->r[RIP].val++;
+    
+    return c;
 }
 
 extern reg_t arch_r[NREGS];
@@ -34,11 +36,21 @@ int main(void)
     main_ctx.r = arch_r;
     main_ctx.i = arch_i;
     
-    main_ctx.mp = 0;
-    main_ctx.mz = 0;
+    main_ctx.mp = malloc(MEMSIZE);
+    main_ctx.mz = MEMSIZE;
     
     main_ctx.get = bget;
     
+    main_ctx.r[RIP].val = MEMOFF;
+    
+    if (main_ctx.mp == 0) {
+        log("Couldn't allocate RAM");
+        exit(-1);
+    }
+    
+    memcpy(&main_ctx.mp[addr2real(main_ctx.r[RIP].val)], fwprog, sizeof(fwprog));
+    memset(&main_ctx.mp[addr2real(main_ctx.r[RIP].val) + sizeof(fwprog)/2], 0xFF, 0xFF);
+
     while (1) {
         decode(&main_ctx);
     }

karch/regs.c

@@ -39,5 +39,6 @@ reg_t arch_r[NREGS] =
     { "cr7", "Control register 7", 0, CTL },
     { "rip", "Instruction pointer", 0, RES },
     { "flg", "Flags register",      0, RES },
+    { "ret", "Return address",      0, RES },
 };