From 2ea32f4e7f26c44fcfcddcb26ae529b23babf7e3 Mon Sep 17 00:00:00 2001
From: hpa <hpa>
Date: Sun, 21 Aug 2005 06:18:54 +0000
Subject: [PATCH] Correct the code related to the run kernel image API
 function.

---
 cmdline.inc          |  7 ++-----
 com32/modules/menu.c | 46 ++++++++++++++++++++++------------------------
 comboot.inc          | 48 +++++++++++++++++++++++++++++++++++-------------
 3 files changed, 59 insertions(+), 42 deletions(-)

diff --git a/cmdline.inc b/cmdline.inc
index 9b636e3..d1cb261 100644
--- a/cmdline.inc
+++ b/cmdline.inc
@@ -23,17 +23,14 @@
 ; Assumes DS == CS
 make_plain_cmdline:
 		push es
-		; ui.inc has already copied the actual command line
+		; ui.inc has already copied any APPEND options
 		mov ax,real_mode_seg
 		mov es,ax
 
 		mov si,[CmdOptPtr]
 		mov di,[CmdLinePtr]
 		
-.loop:		lodsb
-		stosb
-		and al,al
-		jnz .loop
+		call strcpy
 
 		dec di
 		mov [CmdLinePtr],di
diff --git a/com32/modules/menu.c b/com32/modules/menu.c
index d67f5b5..40270c1 100644
--- a/com32/modules/menu.c
+++ b/com32/modules/menu.c
@@ -588,40 +588,38 @@ run_menu(void)
 
 
 static void
-execute(char *cmdline)
+execute(const char *cmdline)
 {
 #ifdef __COM32__
   com32sys_t ireg;
+  const char *p;
+  char *q = __com32.cs_bounce;
+  const char *kernel, *args;
+
   memset(&ireg, 0, sizeof ireg);
 
-  if ( !strncmp(cmdline, ".localboot", 10) && isspace(cmdline[10]) ) {
-    unsigned long localboot = strtoul(cmdline+10, NULL, 0);
-    
+  kernel = q;
+  p = cmdline;
+  while ( *p && !isspace(*p) ) {
+    *q++ = *p++;
+  }
+  *q++ = '\0';
+  
+  args = q;
+  while ( *p && isspace(*p) )
+    p++;
+  
+  strcpy(q, p);
+
+  if ( !strcmp(kernel, ".localboot") ) {
     ireg.eax.w[0] = 0x0014;	/* Local boot */
-    ireg.edx.w[0] = localboot;
+    ireg.edx.w[0] = strtoul(args, NULL, 0);
   } else {
-    const char *p;
-    char *q = __com32.cs_bounce;
-    const char *kernel, *args;
-
-    kernel = q;
-    p = cmdline;
-    while ( *p && !isspace(*p) ) {
-      *p++ = *q++;
-    }
-    *q++ = '\0';
-
-    args = q;
-    while ( *p && isspace(*p) )
-      p++;
-      
-    strcpy(q, p);
-
-    ireg.eax.w[0] = 0x0016;
+    ireg.eax.w[0] = 0x0016;	/* Run kernel image */
     ireg.esi.w[0] = OFFS(kernel);
     ireg.ds       = SEG(kernel);
     ireg.ebx.w[0] = OFFS(args);
-    ireg.es       = SEG(kernel);
+    ireg.es       = SEG(args);
     /* ireg.ecx.l    = 0; */		/* We do ipappend "manually" */
     /* ireg.edx.l    = 0; */
   }
diff --git a/comboot.inc b/comboot.inc
index 91e260a..6cab6c4 100644
--- a/comboot.inc
+++ b/comboot.inc
@@ -415,17 +415,13 @@ comapi_open:
 		pop di
 		pop ds
 		call searchdir
-		jz .err
+		jz comapi_err
 		mov P_AX,ax
 		mov P_HAX,dx
 		mov P_CX,SECTOR_SIZE
 		mov P_SI,si
 		clc
 		ret
-.err:
-		stc
-		ret
-
 
 ;
 ; INT 22h AX=0007h	Read file
@@ -694,30 +690,53 @@ comapi_runkernel:
 		pop di
 		pop ds
 		call searchdir
-		jz comapi_err			; Kernel doesn't exist
+		jz comapi_err
 
 		; The kernel image was found, so we can load it...
 		mov [Kernel_SI],si
 		mov [Kernel_EAX],ax
 		mov [Kernel_EAX+2],dx
 		
+		; It's not just possible, but quite likely, that ES:BX
+		; points into real_mode_seg, so we need to exercise some
+		; special care here... use xfer_buf_seg as an intermediary
+		push ds
 		push es
+		mov ax,xfer_buf_seg
 		mov ds,P_ES
 		mov si,P_BX
-		push word real_mode_seg
-		pop es
-		mov di,cmd_line_here
+		mov es,ax
+		xor di,di
 		call strcpy
-		dec di
-		mov [CmdLinePtr],di
 		pop es
-		
+		pop ds
+
 %if IS_PXELINUX
 		mov al,P_CL
 		mov [IPAppend],al
 %endif
 
-		mov bx,kernel_good_saved
+		xor ax,ax
+		mov bx,.finish
+		jmp comboot_exit_special
+
+.finish:
+		; Copy the command line into its proper place
+		push ds
+		push es
+		mov ax,xfer_buf_seg
+		mov dx,real_mode_seg
+		mov ds,ax
+		mov es,dx
+		xor si,si
+		mov di,cmd_line_here
+		call strcpy
+		mov byte [es:di-1],' '		; Simulate APPEND
+		pop es
+		pop ds
+		mov [CmdLinePtr],di
+		mov word [CmdOptPtr],zero_string
+		jmp kernel_good_saved
 
 		section .data
 int21_table:
@@ -757,11 +776,14 @@ int22_table:
 		dw comapi_idle		; 0013 idle call
 		dw comapi_localboot	; 0014 local boot
 		dw comapi_features	; 0015 feature flags
+		dw comapi_runkernel	; 0016 run kernel image
 int22_count	equ ($-int22_table)/2
 
 APIKeyWait	db 0
 APIKeyFlag	db 0
 
+zero_string	db 0			; Empty, null-terminated string
+
 ;
 ; This is the feature flag array for INT 22h AX=0015h
 feature_flags:
-- 
2.7.4