death_screen

as/k-as.py

@@ -631,28 +631,29 @@ def parse_instr(line):
                 if imm1 == '1':
                     # [reg+reg]
                     if imm2 == '0':
-                        instr_args += "%%imm8 {} {} {}".format(fmts["m_rr"]|mlen, reg1, reg2)
+                        instr_args += "%%imm8 {} {} {}".format(fmts["m_rr"]|mlen, '$'+reg1, '$'+reg2)
                         size += 3
 
                     # [reg+reg+imm]
                     else:
-                        instr_args += "%%imm8 {} {} {} %%signed %%imm16 {}".format(fmts["m_rriw"]|mlen, reg1, reg2, imm2)
+                        instr_args += "%%imm8 {} {} {} %%signed %%imm16 {}"\
+                            .format(fmts["m_rriw"]|mlen, '$'+reg1, '$'+reg2, imm2)
                         size += 5
 
                 # [reg+reg*imm+imm]
                 else:
                     instr_args += "%%imm8 {} {} {} %%imm8 {} %%signed %%imm32 {}"\
-                        .format(fmts["m_rrii"]|mlen, reg1, reg2, imm1, imm2)
+                        .format(fmts["m_rrii"]|mlen, '$'+reg1, '$'+reg2, imm1, imm2)
                     size += 8
 
             # [reg]
-            elif word in pregs:
+            elif '$'+word in pregs:
-                instr_args += "%%imm8 {} {}".format(fmts["m_r"]|mlen, word)
+                instr_args += "%%imm8 {} {}".format(fmts["m_r"]|mlen, '$'+word)
                 size += 2
 
             # [imm], converted to [zero+imm]
             else:
-                instr_args += "%%imm8 {} zero zero %%signed %%imm32 {}".format(fmts["m_rrid"]|mlen, word)
+                instr_args += "%%imm8 {} $zero $zero %%signed %%imm32 {}".format(fmts["m_rrid"]|mlen, word)
                 size += 7
 
             continue
@@ -669,8 +670,8 @@ def parse_instr(line):
 
         # register index $reg
         if len(word) == 4 and word[0] == '$':
-            if word[1:] in pregs:
+            if '$'+word[1:] in pregs:
-                word = str(pregs[word[1:]])
+                word = str(pregs['$'+word[1:]])
             # fallthrough
 
         # immediates
@@ -700,9 +701,9 @@ def parse_instr(line):
             continue
 
         # register
-        elif word in pregs:
+        elif '$'+word in pregs:
             size += 1
-            instr_args += word
+            instr_args += '$'+word
             continue
 
         # it's a label (a 32-bit immediate)

as/regs.lst

@@ -1,34 +1,34 @@
-rzx zr zero
+$rzx $zero
-cr0 c0
+$cr0
-cr1 c1
+$cr1
-cr2 c2
+$cr2
-rfx fx
+$rfx
-rip ip
+$rip
-rbp bp
+$rbp
-rsp sp
+$rsp
 
-rax ax r0
+$rax $r0
-rbx bx r1
+$rbx $r1
-rcx cx r2
+$rcx $r2
-rdx dx r3
+$rdx $r3
-rsi si r4
+$rsi $r4
-rdi di r5
+$rdi $r5
-ax0 a0 r6
+$ax0 $r6
-ax1 a1 r7
+$ax1 $r7
-ax2 a2 r8
+$ax2 $r8
-ax3 a3 r9
+$ax3 $r9
-ax4 a4 r10
+$ax4 $r10
-ax5 a5 r11
+$ax5 $r11
 
-nx0 n0 r12
+$nx0 $r12
-nx1 n1 r13
+$nx1 $r13
-nx2 n2 r14
+$nx2 $r14
-nx3 n3 r15
+$nx3 $r15
-nx4 n4 r16
+$nx4 $r16
-nx5 n5 r17
+$nx5 $r17
-nx6 n6 r18
+$nx6 $r18
-nx7 n7 r19
+$nx7 $r19
-nx8 n8 r20
+$nx8 $r20
-grp gp
+$grp $r21
-trp tp
+$trp $r22
-srp sp
+$srp $r22

ka/crt/crt.k

@@ -33,6 +33,7 @@ FNAME_MAX   := 0x0000000000000080
 ;
 
 PRN_CLEAR   := 0x000000008BF00001
+PRN_FLUSH   := 0x000000008BF00002
 
 ;
 ; CRT librairies

ka/crt/fmt/ltostr.k

@@ -20,6 +20,7 @@ utoa:
 ;
 ltostr:
     mov rax, ax0
+    mov rcx, zero
 
     ; make sure base is in [2, 32]
     b.b ax2, 2, .bad
@@ -60,7 +61,7 @@ ltostr:
     ; add minus flag, null-terminate and reverse
 .fini:
     mov.cxnz b[ax0], '-'
-    add.cxnz ax0, ax0, 1
+    inc.cxnz ax0, 1
 
     mov b[ax0], zero
 

ka/doskrnl.k

@@ -26,6 +26,8 @@ start:
     mov rsp, DOSKRNL_STACK
     mov rbp, zero
 
+    ;dump
+
     call main
 
     crash
@@ -42,4 +44,5 @@ include "sys/intr/common.k"
 include "sys/intr/trap0.k"
 
 include "sys/main.k"
+include "sys/dumprf.k"
 

ka/sys/dumprf.k

@@ -0,0 +1,127 @@
+; The OS/K Team licenses this file to you under the MIT license.
+; See the LICENSE file in the project root for more information.
+
+dumprf:
+    push rbp
+    mov rbp, rsp
+
+    push r12
+    mov r12, ax0
+
+    call RFS.LoadReg, r12, $cr2
+    push rax
+
+    call RFS.LoadReg, r12, $cr1
+    push rax
+
+    call RFS.LoadReg, r12, $cr0
+    push rax
+
+    call RFS.LoadReg, r12, $rfx
+    push rax
+
+    call RFS.LoadReg, r12, $rip
+    push rax
+
+    push r12
+    call printf, .dmp1
+
+    call RFS.LoadReg, r12, $srp
+    push rax
+
+    call RFS.LoadReg, r12, $trp
+    push rax
+
+    push 0 # fixme
+
+    call RFS.LoadReg, r12, $rbp
+    push rax
+
+    call RFS.LoadReg, r12, $rsp
+    push rax
+
+    call printf, .dmp2
+
+    call RFS.LoadReg, r12, $ax5
+    push rax
+
+    call RFS.LoadReg, r12, $ax4
+    push rax
+
+    call RFS.LoadReg, r12, $ax3
+    push rax
+
+    call RFS.LoadReg, r12, $ax2
+    push rax
+
+    call RFS.LoadReg, r12, $ax1
+    push rax
+
+    call RFS.LoadReg, r12, $ax0
+    push rax
+
+    call printf, .dmp3
+
+    call RFS.LoadReg, r12, $rdi
+    push rax
+
+    call RFS.LoadReg, r12, $rsi
+    push rax
+
+    call RFS.LoadReg, r12, $rdx
+    push rax
+
+    call RFS.LoadReg, r12, $rcx
+    push rax
+
+    call RFS.LoadReg, r12, $rbx
+    push rax
+
+    call RFS.LoadReg, r12, $rax
+    push rax
+
+    call printf, .dmp4
+
+    call RFS.LoadReg, r12, $r17
+    push rax
+
+    call RFS.LoadReg, r12, $r16
+    push rax
+
+    call RFS.LoadReg, r12, $r15
+    push rax
+
+    call RFS.LoadReg, r12, $r14
+    push rax
+
+    call RFS.LoadReg, r12, $r13
+    push rax
+
+    call RFS.LoadReg, r12, $r12
+    push rax
+
+    call printf, .dmp5
+
+    call RFS.LoadReg, r12, $r20
+    push rax
+
+    call RFS.LoadReg, r12, $r19
+    push rax
+
+    call RFS.LoadReg, r12, $r18
+    push rax
+
+    call printf, .dmp6
+
+    pop r12
+
+    leave
+    ret
+
+.dmp1 = "Environ #1:\nfrm=0d%d rip=0x%x rfx=0x%x\ncr0=0x%x cr1=0x%x cr2=0x%x\n\n"
+.dmp2 = "Environ #2:\nrsp=0x%x rbp=0x%x ind=0d%d\ngrp=0x%x trp=0x%x srp=0x%x\n\n"
+.dmp3 = "Argument:\nr12=0x%x ax1=0x%x ax2=0x%x\nax3=0x%x ax4=0x%x ax5=0x%x\n\n"
+.dmp4 = "Volatile:\nrax=0x%x rbx=0x%x rcx=0x%x\nrdx=0x%x rsi=0x%x rdi=0x%x\n\n"
+.dmp5 = "Persistent:\nr12=0x%x r13=0x%x r14=0x%x\nr15=0x%x r16=0x%x r17=0x%x\n"
+.dmp6 = "r18=0x%x r19=0x%x r20=0x%x\n"
+

ka/sys/intr/common.k

@@ -4,7 +4,7 @@
 TrapHandlers.prolog:
     mov rbp, rsp
 
-    ; nx0 = caller's cr2
+    ; rax = caller's cr2
     call RFS.LoadReg, r14, $cr2
 
     ; we don't preserve the r12 we got
@@ -14,7 +14,6 @@ TrapHandlers.prolog:
     jmp rcx
 
 TrapHandlers.epilog:
-
     ; TRAP return values: RAX-RDX
 
     mov ax2, rax
@@ -27,3 +26,58 @@ TrapHandlers.epilog:
 
     iret
 
+ScreenOfDeath:
+    push r12
+    mov r12, ax0
+
+    prn 10
+    prn PRN_CLEAR
+    prn PRN_FLUSH
+
+    call print, .scr1
+
+    b.nz r14, zero, .not_con
+    push .scr2_con
+    jmp .do_print
+
+.not_con:
+    b.l r14, 4, .not_krn
+    push .scr2_krn
+    jmp .do_print
+
+.not_krn:
+    push .scr2_usr
+
+.do_print:
+    push r14
+    push r12
+    call printf, .scr2
+    inc rsp, 24
+
+    call dumprf, r14
+    prn 10
+
+    call print, .scr3
+
+.loop:
+    pause
+    pause
+
+    scan rax
+    jmp.axz .loop
+
+    b.z rax, 0x0A, trap0_handler.handle_Exit
+    b.z rax, 0x1B, trap0_handler.handle_Shutdown
+
+    jmp .loop
+
+    crash
+
+.scr1 = "-------- Unhandled EXCEPTION, TRAP/SYSCALL or INTERRUPT\n"
+.scr2 = "Offense description: %s\nOffending frame: %d (%s)\n\n"
+.scr3 = "Press:\n    ENTER to procede to COMMAND.COM\n    ESCAPE to shutdown machine\n\n"
+
+.scr2_con = "dedicated command.com frame"
+.scr2_usr = "userspace application frame"
+.scr2_krn = "exception/interrupt handler"
+

ka/sys/intr/trap0.k

@@ -23,9 +23,7 @@ trap0_handler:
     b.z rax, Sys.FindFirst, .handle_FindFirst
     b.z rax, Sys.EnterHaltMode, .handle_HaltMode
 
-    mov rax, 1 << 63
+    call ScreenOfDeath, .badsyscall
-    mov rcx, 1 << 63
-    mov rdx, 1 << 63
 
 .fini.savecx:
     mov ax2, rcx
@@ -34,6 +32,8 @@ trap0_handler:
 .fini:
     jmp TrapHandlers.epilog
 
+.badsyscall = "Invalid syscall number in RAX"
+
 ;------------------------------------------------;
 ;             Syscall implementations            ;
 ;------------------------------------------------;

ka/usr/cmd/main.k

@@ -130,6 +130,10 @@ main:
     call strcmp, argv0, .builtin_cls
     jmp.axz .handle_CLS
 
+.builtin_crash = "crash"
+    call strcmp, argv0, .builtin_crash
+    jmp.axz .handle_CRASH
+
 .builtin_date = "date"
     call strcmp, argv0, .builtin_date
     jmp.axz .handle_DATE
@@ -195,6 +199,12 @@ main:
     prn PRN_CLEAR
     jmp .print_prompt
 
+.handle_CRASH:
+    mov rax, 0xDEADBEEF
+    trap 0
+
+    jmp .print_prompt
+
 .handle_DATE:
     call GetTimeUTC
 

vm/in/MISC

@@ -24,6 +24,11 @@ dump
 # Misc. instructions                                                        #
 #---------------------------------------------------------------------------#
 
+#
+# Throws #UDF ("undefined behaviour")
+#
+udf
+
 #
 # Pause the CPU for a very short amount of time (PAUSE)
 # Used in spin-type loops

vm/in/misc.c

@@ -11,6 +11,7 @@
 
 IMPL_START(into) { INTO(); return 0; }
 IMPL_START(pause) { usleep(5000); return 0; }
+IMPL_START(udf) { _except(E_UDF, "UDF instruction"); }
 
 //----------------------------------------------------------------------------//
 
@@ -123,7 +124,9 @@ IMPL_START(dswap)
 
 //----------------------------------------------------------------------------//
 
+#define PRN_MAGIC_MASK  0x8BF00000
 #define PRN_CLEAR_MAGIC 0x8BF00001
+#define PRN_FLUSH_MAGIC 0x8BF00002
 
 IMPL_START(prn)
 {
@@ -132,8 +135,22 @@ IMPL_START(prn)
     ulong v = p1->val;
 
     // Magic value? :)
-    if (__builtin_expect(v == PRN_CLEAR_MAGIC, 0))
+    if (__builtin_expect((v & PRN_MAGIC_MASK) > 0, 0))
-        console_clear();
+    {
+        switch (v)
+        {
+        case PRN_CLEAR_MAGIC:
+            console_clear();
+            break;
+
+        case PRN_FLUSH_MAGIC:
+            console_flushkeybuf();
+            break;
+
+        default:
+            _except(E_ILL, "Bad PRN magic");
+        }
+    }
 
     else if (v > 0)
         console_putc((char)v);

vm/pc/keybd.c

@@ -37,6 +37,12 @@ keycode_t console_scankeybuf(void)
     return 0;
 }
 
+void console_flushkeybuf(void)
+{
+    memset(keybuf, 0, KEYBUFSIZE);
+    keybuf_last = keybuf_ptr = &keybuf[0];
+}
+
 #define QKEY(key, c, cshift, cmode, calt, cgui)                             \
 _QKEY(SDLK_##key, c, cshift, cmode, calt, cgui)
 
@@ -70,6 +76,8 @@ void console_handle_input(SDL_Keycode key)
         case SDLK_SPACE:        code = ' ';     break;
         case SDLK_BACKSPACE:    code = '\b';    break;
 
+        case SDLK_ESCAPE:       code = 0x1B;    break;
+
         case SDLK_RETURN:
         case SDLK_RETURN2:
             code = '\n';

vm/pc/keybd.h

@@ -12,6 +12,8 @@ extern keycode_t *keybuf_ptr;
 keycode_t console_getkey(void);
 keycode_t console_scankeybuf(void);
 
+void console_flushkeybuf(void);
+
 void console_addkey(keycode_t);
 void console_handle_input(SDL_Keycode key);