From 7937de6ef0f775ef1d5ef167e5ade7795176caf0 Mon Sep 17 00:00:00 2001
From: Lucia Ceionia <lucia@noreply.ceionius.com>
Date: Thu, 2 Feb 2023 01:44:35 -0600
Subject: [PATCH] Added fun fault recovery :3   (I think I spotted a race
 condition in exception handling during testing, but whatever, that can wait)

---
 kernel.c |  7 ++++++-
 v86.nasm | 25 +++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/kernel.c b/kernel.c
index 7ce9374..97473ab 100644
--- a/kernel.c
+++ b/kernel.c
@@ -65,6 +65,7 @@ extern struct Int13DiskPacket_t v86disk_addr_packet;
 
 extern void enter_v86(uint32_t ss, uint32_t esp, uint32_t cs, uint32_t eip);
 extern void v86Test();
+extern void v86TransFlag();
 extern void v86GfxMode();
 extern void v86TextMode();
 extern void v86DiskRead();
@@ -120,10 +121,14 @@ void error_environment() {
     ensure_v86env();
     FARPTR v86_entry = i386LinearToFp(v86TextMode);
     enter_v86(0x8000, 0xFF00, FP_SEG(v86_entry), FP_OFF(v86_entry));
-    printStr("Oh noes!!! System error! ;c", &error_screen[80]);
+    printStr("Oh noes!!! System error! ;c    Press E for a fun recovery :3", &error_screen[80]);
     uint16_t *vga_text = ((uint16_t*)0xB8000);
     for (int i = 0; i < 80*50; i++)
         vga_text[i] = error_screen[i];
+    uint8_t key;
+    for (key = get_key(); key != 'e' && key != 'E'; key = get_key());
+    v86_entry = i386LinearToFp(v86TransFlag);
+    enter_v86(0x8000, 0xFF00, FP_SEG(v86_entry), FP_OFF(v86_entry));
 }
 
 /*
diff --git a/v86.nasm b/v86.nasm
index 7a0e801..4f872c2 100644
--- a/v86.nasm
+++ b/v86.nasm
@@ -45,6 +45,31 @@ int 3
 int 0x30 ; exit
 jmp $
 
+global v86TransFlag
+v86TransFlag:
+push cs
+pop es
+mov ax, 0x13
+int 0x10
+mov ax,0x1012
+xor bx,bx
+mov cx,5
+mov dx,.c
+int 0x10
+push 0xa000
+pop es
+xor di,di
+xor ax,ax
+.loop:
+mov cx, 12800
+rep stosb
+inc ax
+cmp ax,5
+jl .loop
+int 0x30
+jmp $
+.c: db `\0263>=*.\?\?\?=*.\0263>`
+
 global v86GfxMode
 v86GfxMode:
 mov ax, 0x13