From b890d67ff4368bdf0fde06d5ea8df58047abd918 Mon Sep 17 00:00:00 2001
From: julianb0 <spectral@os-k.eu>
Date: Tue, 6 Aug 2019 23:21:37 +0200
Subject: [PATCH] vm

---
 as/k-as.py            |  1 +
 ka/doskrnl.k          |  3 ++-
 ka/sys/intr/common.k  | 14 ++++++++------
 ka/sys/intr/excepts.k | 29 +++++++++++++++++++++++++++++
 ka/sys/intr/trap0.k   |  9 ++++++---
 ka/sys/main.k         | 23 +++++++++++++++++------
 ka/usr/cmd/main.k     |  3 +++
 7 files changed, 66 insertions(+), 16 deletions(-)
 create mode 100644 ka/sys/intr/excepts.k

diff --git a/as/k-as.py b/as/k-as.py
index f6d0da1..8612a48 100755
--- a/as/k-as.py
+++ b/as/k-as.py
@@ -239,6 +239,7 @@ def parse():
 #-------------------------------------------------------------------------------
 
 escape_dict = {
+    '0':    '\0',
     'n':    '\n',
     't':    '\t',
     'r':    '\r',
diff --git a/ka/doskrnl.k b/ka/doskrnl.k
index 1a039d4..a20e61a 100644
--- a/ka/doskrnl.k
+++ b/ka/doskrnl.k
@@ -40,9 +40,10 @@ include "sys/drv/cpudev.k"
 include "sys/drv/memdev.k"
 include "sys/drv/diskdev.k"
 
+include "sys/intr/excepts.k"
 include "sys/intr/common.k"
 include "sys/intr/trap0.k"
 
-include "sys/main.k"
 include "sys/dumprf.k"
+include "sys/main.k"
 
diff --git a/ka/sys/intr/common.k b/ka/sys/intr/common.k
index c4ee327..252e355 100644
--- a/ka/sys/intr/common.k
+++ b/ka/sys/intr/common.k
@@ -2,7 +2,7 @@
 ; See the LICENSE file in the project root for more information.
 
 TrapHandlers.prolog:
-    mov rbp, rsp
+    mov rbp, zero
 
     ; rax = caller's cr2
     call RFS.LoadReg, r14, $cr2
@@ -34,7 +34,9 @@ ScreenOfDeath:
     prn PRN_CLEAR
     prn PRN_FLUSH
 
-    call print, .scr1
+    push ax1
+    call printf, .scr1
+    pop zero
 
     b.nz r14, zero, .not_con
     push .scr2_con
@@ -66,15 +68,15 @@ ScreenOfDeath:
     scan rax
     jmp.axz .loop
 
-    b.z rax, 0x0A, trap0_handler.handle_Exit
-    b.z rax, 0x1B, trap0_handler.handle_Shutdown
+    b.z rax, 0x0A, DefaultTrapHandler.handle_Exit
+    b.z rax, 0x1B, DefaultTrapHandler.handle_Shutdown
 
     jmp .loop
 
     crash
 
-.scr1 = "-------- Unhandled EXCEPTION, TRAP/SYSCALL or INTERRUPT\n"
-.scr2 = "Offense description: %s\nOffending frame: %d (%s)\n\n"
+.scr1 = "-------- Unhandled EXCEPTION, TRAP/SYSCALL or INTERRUPT (code %d)\n"
+.scr2 = "Description: %s\nFrame: %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"
diff --git a/ka/sys/intr/excepts.k b/ka/sys/intr/excepts.k
new file mode 100644
index 0000000..7742829
--- /dev/null
+++ b/ka/sys/intr/excepts.k
@@ -0,0 +1,29 @@
+; The OS/K Team licenses this file to you under the MIT license.
+; See the LICENSE file in the project root for more information.
+
+DefaultExceptionHandler:
+    mov rsp, EXCT0_STACK
+    mov ax1, r12
+
+    b.z r12, zero, DefaultTrapHandler.handle_Shutdown
+    b.a r12, 11, .unknown
+
+    mov rsi, .err_ukn
+    lea ax0, b[rsi + r12 * 32]
+    call ScreenOfDeath
+
+.unknown:
+    call ScreenOfDeath, .err_ukn
+    crash
+
+.err_ukn = "Unknown exception number\0\0\0\0\0\0\0"
+.err_udf = "Undefined behaviour exception\0\0"
+.err_ill = "Ill-formed exception exception\0"
+.err_acc = "Invalid memory access exception"
+.err_sys = "Supervisor-only exception used\0"
+.err_dbf = "Double fault exception~~~~~~~~\0"
+.err_imp = "Feat. not implemented exception"
+.err_ali = "Misalignmed address exception\0\0"
+.err_brk = "BREAK key (Ctrl+C) exception\0\0\0"
+.err_ovf = "Overflow flag raised exception\0"
+.err_div = "Division by zero exception\0\0\0\0\0"
diff --git a/ka/sys/intr/trap0.k b/ka/sys/intr/trap0.k
index cfde799..1b34a41 100644
--- a/ka/sys/intr/trap0.k
+++ b/ka/sys/intr/trap0.k
@@ -1,7 +1,7 @@
 ; The OS/K Team licenses this file to you under the MIT license.
 ; See the LICENSE file in the project root for more information.
 
-trap0_handler:
+DefaultTrapHandler:
 
 .init:
     mov rcx, .text
@@ -23,7 +23,7 @@ trap0_handler:
     b.z rax, Sys.FindFirst, .handle_FindFirst
     b.z rax, Sys.EnterHaltMode, .handle_HaltMode
 
-    call ScreenOfDeath, .badsyscall
+    call ScreenOfDeath, .badsyscall, r13
 
 .fini.savecx:
     mov ax2, rcx
@@ -83,7 +83,7 @@ trap0_handler:
     call RFS.StoreReg, zero, $cr2
 
     ; Return frame
-    mov q[rbp-16], zero
+    mov r14, zero
 
     jmp .fini
 
@@ -130,6 +130,9 @@ trap0_handler:
 ; Misc.
 ;
 .handle_Shutdown:
+    mov ax0, zero
+    call IDT.DelHandler
+
     stop
 
 .handle_HaltMode:
diff --git a/ka/sys/main.k b/ka/sys/main.k
index c931f68..4bde9e4 100644
--- a/ka/sys/main.k
+++ b/ka/sys/main.k
@@ -12,20 +12,30 @@ PrintBootMsg:
 ;
 InitSyscalls:
     mov ax0, 1
-
-.prepare_next:
     call RFS.ActivateFrame
 
     mov ax1, $rip
-    mov ax2, trap0_handler
+    mov ax2, DefaultTrapHandler
     call RFS.StoreReg
-    
-    mov ax1, ax0
-    inc ax0, 255    # TRAP no. (ax0 - 1)
+
+    mov ax0, 256
+    mov ax1, 1
     call IDT.AddHandler
 
     ret
 
+InitExcepts:
+    mov ax0, 2
+    call RFS.ActivateFrame
+
+    mov ax1, $rip
+    mov ax2, DefaultExceptionHandler
+    call RFS.StoreReg
+
+    mov ax0, zero
+    mov ax1, 2
+    call IDT.AddHandler
+
 SwitchToCMD:
     mov rax, Sys.Exit
     trap 0
@@ -36,6 +46,7 @@ SwitchToCMD:
 main:
     call PrintBootMsg
     call InitSyscalls
+    call InitExcepts
     call SwitchToCMD
     ret
 
diff --git a/ka/usr/cmd/main.k b/ka/usr/cmd/main.k
index 6e1dc8b..02463a9 100644
--- a/ka/usr/cmd/main.k
+++ b/ka/usr/cmd/main.k
@@ -40,6 +40,9 @@ main:
     scan rax
     jmp.axz .input_loop
 
+    ; ESC key pressed?
+    b.z rax, 0x1B, .handle_EXIT
+
     ; backspace character?
     b.nz rax, 8, .handle_input