Merge in changes from SYSLINUX 1.75syslinux-2.00-pre4

8 files changed, 126 insertions, 40 deletions

diff --git a/Makefile.private b/Makefile.private
index 164400b6..fee4f3b6 100644
--- a/Makefile.private
+++ b/Makefile.private
@@ -43,7 +43,8 @@ release:
 	cp -rP $(SOURCES) $(DOCS) $(OTHER) release/syslinux-$(VERSION)
 	find release/syslinux-$(VERSION) -name CVS -type d -print0 | \
 		xargs -0rt rm -rf
-	ln $(PRIVATE) release/syslinux-$(VERSION)
+	ln -f $(PRIVATE) release/syslinux-$(VERSION)
+	cd release/syslinux-$(VERSION) && $(MAKE) depend
 	cd release/syslinux-$(VERSION) && $(MAKE) official
 	cd release/syslinux-$(VERSION) && rm -f $(PRIVATE)
 	cd release && tar cvvf - syslinux-$(VERSION) | \
diff --git a/NEWS b/NEWS
index 42068e62..954c4e24 100644
--- a/NEWS
+++ b/NEWS
@@ -34,6 +34,11 @@ Changes in 1.75:
 	  bigger.
 	* PXELINUX: Put the PXE stack back in the init state before
 	  invoking a chain-loaded NBP.
+	* PXELINUX: Actually found the combination of calls that
+	  allows some (most?) PXE 2+ stacks to be unloaded from memory
+	  properly.
+	* PXELINUX: Add "keeppxe" command-line option to disable
+	  the standard unloading of the PXE stack.
 
 Changes in 1.74:
 	* SYSLINUX: fix bug that would cause valid kernel images to be
diff --git a/bootsect.inc b/bootsect.inc
index 7d32ba8c..d3e50fc9 100644
--- a/bootsect.inc
+++ b/bootsect.inc
@@ -80,9 +80,7 @@ load_bootsec:
 %elif IS_PXELINUX
 		; Close the UDP stack so the PXE stack is in a known state for
 		; the new NBP
-		mov di,pxe_udp_close_pkt
-		mov bx,PXENV_UDP_CLOSE
-		call far [PXENVEntry]
+		call reset_pxe
 %endif
 
 		pop ecx			; Byte count to copy
diff --git a/com32.inc b/com32.inc
index ac0440f8..3d445c10 100644
--- a/com32.inc
+++ b/com32.inc
@@ -55,10 +55,9 @@ com32_start:
 		mov ebx,com32_call_start	; Where to go in PM
 
 com32_enter_pm:
+		cli
 		mov [SavedSSSP],sp
 		mov [SavedSSSP+2],ss
-
-		cli
 		cld
 		call a20_test
 		jnz .a20ok
diff --git a/pxe.inc b/pxe.inc
index 759115f6..92da3bbd 100644
--- a/pxe.inc
+++ b/pxe.inc
@@ -53,14 +53,16 @@
 %define PXENV_UNDI_GET_NIC_TYPE		0012h
 %define PXENV_UNDI_GET_IFACE_INFO	0013h
 %define PXENV_UNDI_ISR			0014h
-%define	PXENV_STOP_UNDI			0015h	; HUH????
-%define PXENV_UNDI_GET_STATE		0016h
+%define	PXENV_STOP_UNDI			0015h	; Overlap...?
+%define PXENV_UNDI_GET_STATE		0015h	; Overlap...?
 
 %define PXENV_UNLOAD_STACK		0070h
 %define PXENV_GET_CACHED_INFO		0071h
 %define PXENV_RESTART_DHCP		0072h
 %define PXENV_RESTART_TFTP		0073h
 %define PXENV_MODE_SWITCH		0074h
+%define PXENV_START_BASE		0075h
+%define PXENV_STOP_BASE			0076h
 
 %define PXENV_EXIT_SUCCESS 0x0000 
 %define PXENV_EXIT_FAILURE 0x0001  
diff --git a/pxelinux.asm b/pxelinux.asm
index 67894fa1..125d0183 100644
--- a/pxelinux.asm
+++ b/pxelinux.asm
@@ -222,6 +222,7 @@ KernelExtPtr	resw 1			; During search, final null pointer
 IPOptionLen	resw 1			; Length of IPOption
 LocalBootType	resw 1			; Local boot return code
 RealBaseMem	resw 1			; Amount of DOS memory after freeing
+APIVer		resw 1			; PXE API version found
 TextAttrBX      equ $
 TextAttribute   resb 1			; Text attribute for message file
 TextPage        resb 1			; Active display page
@@ -247,6 +248,15 @@ VGAFileBuf	resb FILENAME_MAX	; Unmangled VGA image name
 VGAFileBufEnd	equ $
 VGAFileMBuf	resb FILENAME_MAX	; Mangled VGA image name
 
+;
+; PXE packets which don't need static initialization
+;
+		alignb 4
+pxe_unload_stack_pkt:
+.status:	resw 1			; Status
+.reserved:	resw 10			; Reserved
+pxe_unload_stack_pkt_len	equ $-pxe_unload_stack_pkt
+
 		alignb tftp_port_t_size
 Sockets		resb MAX_SOCKETS*tftp_port_t_size
 
@@ -306,6 +316,15 @@ _start1:
 		call writestr
 
 ;
+; Assume API version 2.1, in case we find the !PXE structure without
+; finding the PXENV+ structure.  This should really look at the Base
+; Code ROM ID structure in have_pxe, but this is adequate for now --
+; if we have !PXE, we have to be 2.1 or higher, and we don't care
+; about higher versions than that.
+;
+		mov word [APIVer],0201h
+
+;
 ; Now we need to find the !PXE structure.  It's *supposed* to be pointed
 ; to by SS:[SP+4], but support INT 1Ah, AX=5650h method as well.
 ;
@@ -343,10 +362,11 @@ have_pxenv:
 		mov si,apiver_str
 		call writestr
 		mov ax,[es:bx+6]
+		mov [APIVer],ax
 		call writehex4
 		call crlf
 
-		cmp word [es:bx+6], 0201h	; API version 2.1 or higher
+		cmp ax,0201h			; API version 2.1 or higher
 		jb old_api
 		mov si,bx
 		mov ax,es
@@ -1923,44 +1943,77 @@ ack_packet:
 ; unload_pxe:
 ;
 ; This function unloads the PXE and UNDI stacks and unclaims
-; the memory.
+; the memory.  Assumes CS == DS == ES.
 ;
 unload_pxe:
-		mov di,pxe_udp_close_pkt
-		mov bx,PXENV_UDP_CLOSE
-		call far [PXENVEntry]
-		mov di,pxe_undi_shutdown_pkt
-		mov bx,PXENV_UNDI_SHUTDOWN
-		call far [PXENVEntry]
+		test byte [KeepPXE],01h		; Should we keep PXE around?
+		jnz reset_pxe
+
+		mov si,new_api_unload
+		cmp byte [APIVer+1],2		; Major API version >= 2?
+		jae .new_api
+		mov si,old_api_unload
+.new_api:
+		
+.call_loop:	xor ax,ax
+		lodsb
+		and ax,ax
+		jz .call_done
+		xchg bx,ax
 		mov di,pxe_unload_stack_pkt
-		mov bx,PXENV_UNLOAD_STACK
+		push di
+		xor ax,ax
+		mov cx,pxe_unload_stack_pkt_len >> 1
+		rep stosw
+		pop di
 		call far [PXENVEntry]
 		jc .cant_free
-		cmp word [pxe_unload_stack_pkt.status],byte PXENV_STATUS_SUCCESS
+		cmp word [pxe_unload_stack_pkt.status],PXENV_STATUS_SUCCESS
 		jne .cant_free
+		jmp .call_loop
+
+.call_done:
+		mov bx,0FF00h
 
-		mov ax,[RealBaseMem]
-		cmp ax,[BIOS_fbm]		; Sanity check
+		mov dx,[RealBaseMem]
+		cmp dx,[BIOS_fbm]		; Sanity check
 		jna .cant_free
+		inc bx
 
 		; Check that PXE actually unhooked the INT 1Ah chain
-		movzx ebx,word [4*0x1a]
+		movzx eax,word [4*0x1a]
 		movzx ecx,word [4*0x1a+2]
 		shl ecx,4
-		add ebx,ecx
-		shr ebx,10
-		cmp bx,ax			; Not in range
+		add eax,ecx
+		shr eax,10
+		cmp ax,dx			; Not in range
 		jae .ok
-		cmp bx,[BIOS_fbm]
-		jae .cant_free		
+		cmp ax,[BIOS_fbm]
+		jae .cant_free
+		; inc bx
 
 .ok:
-		mov [BIOS_fbm],ax
+		mov [BIOS_fbm],dx
 		ret
 		
 .cant_free:
 		mov si,cant_free_msg
-		jmp writestr
+		call writestr
+		xchg ax,bx
+		call writehex4
+		mov al,'-'
+		call writechr
+		mov eax,[4*0x1a]
+		call writehex8
+		jmp crlf
+
+		; We want to keep PXE around, but still we should reset
+		; it to the standard bootup configuration
+reset_pxe:
+		mov bx,PXENV_UDP_CLOSE
+		mov di,pxe_udp_close_pkt
+		call far [PXENVEntry]
+		ret
 
 ;
 ; gendotquad
@@ -2279,7 +2332,7 @@ undi_data_msg	  db 'UNDI data segment at:   ',0
 undi_data_len_msg db 'UNDI data segment size: ',0 
 undi_code_msg	  db 'UNDI code segment at:   ',0
 undi_code_len_msg db 'UNDI code segment size: ',0 
-cant_free_msg	db 'Failed to free base memory, sorry...', CR, LF, 0
+cant_free_msg	db 'Failed to free base memory, error ', 0
 notfound_msg	db 'not found', CR, LF, 0
 myipaddr_msg	db 'My IP address seems to be ',0
 tftpprefix_msg	db 'TFTP prefix: ', 0
@@ -2332,6 +2385,22 @@ exten_table_end:
 PXENVEntry	dw pxe_thunk,0
 
 ;
+; PXE unload sequences
+;
+new_api_unload:
+		db PXENV_UDP_CLOSE
+		db PXENV_UNDI_SHUTDOWN
+		db PXENV_UNLOAD_STACK
+		db PXENV_STOP_UNDI
+		db 0
+old_api_unload:
+		db PXENV_UDP_CLOSE
+		db PXENV_UNDI_SHUTDOWN
+		db PXENV_UNLOAD_STACK
+		db PXENV_UNDI_CLEANUP
+		db 0
+
+;
 ; PXE query packets partially filled in
 ;
 pxe_bootp_query_pkt_2:
@@ -2380,13 +2449,6 @@ pxe_udp_read_pkt:
 .buffersize:	dw 0			; Max packet size
 .buffer:	dw 0, 0			; seg:off of buffer
 
-pxe_unload_stack_pkt:
-.status:	dw 0			; Status
-.reserved:	times 10 db 0		; Reserved
-
-pxe_undi_shutdown_pkt:
-.status:	dw 0			; Status
-
 ;
 ; Misc initialized (data) variables
 ;
@@ -2403,6 +2465,7 @@ NextSocket	dw 49152		; Counter for allocating socket numbers
 VGAFontSize	dw 16			; Defaults to 16 byte font
 UserFont	db 0			; Using a user-specified font
 ScrollAttribute	db 07h			; White on black (for text mode)
+KeepPXE		db 0			; Should PXE be kept around?
 
 ;
 ; TFTP commands
diff --git a/pxelinux.doc b/pxelinux.doc
index 6ee17776..04842f18 100644
--- a/pxelinux.doc
+++ b/pxelinux.doc
@@ -302,6 +302,17 @@ varying degrees of severity.  Please see:
 if known.
 
 
+    ++++ KEEPING THE PXE STACK AROUND ++++
+
+Normally, PXELINUX will unload the PXE and UNDI stacks before invoking
+the kernel.  In special circumstances (for example, when using MEMDISK
+to boot an operating system with an UNDI network driver) it might be
+desirable to keep the PXE stack in memory.  If the option "keeppxe"
+is given on the kernel command line, PXELINUX will keep the PXE and
+UNDI stacks in memory.  (If you don't know what this means, you
+probably don't need it.)
+
+
     ++++ CURRENTLY KNOWN PROBLEMS ++++
 
 The following problems are known with PXELINUX, so far:
@@ -309,10 +320,6 @@ The following problems are known with PXELINUX, so far:
 + Requires a TFTP server which supports the "tsize" option.
 + The error recovery routine doesn't work quite right.  For right now,
   it just does a hard reset - seems good enough.
-+ There may be funnies with memory management.  The PXE spec has no
-  decent way of telling it to free up all memory and unchain any
-  interrupts; it allows the base stack to be unloaded, but not the
-  UNDI driver.
 + We should probably call the UDP receive function in the keyboard
   entry loop, so that we answer ARP requests.
 + Boot sectors/disk images are not supported yet.
diff --git a/runkernel.inc b/runkernel.inc
index 3ee28f9b..f968168f 100644
--- a/runkernel.inc
+++ b/runkernel.inc
@@ -145,6 +145,16 @@ get_next_opt:   lodsb
 		je is_vga_cmd
                 cmp eax,'mem='
 		je is_mem_cmd
+%if IS_PXELINUX
+		cmp eax,'keep'			; Is it "keeppxe"?
+		jne .notkeep
+		cmp dword [si+3],'ppxe'
+		jne .notkeep
+		cmp byte [si+7],' '		; Must be whitespace or EOS
+		ja .notkeep
+		or byte [cs:KeepPXE],1
+.notkeep:
+%endif
                 push es                         ; Save ES -> real_mode_seg
                 push cs
                 pop es                          ; Set ES <- normal DS
@@ -152,6 +162,7 @@ get_next_opt:   lodsb
 		mov cx,initrd_cmd_len
 		repe cmpsb
                 jne not_initrd
+
 		mov di,InitRD
                 push si                         ; mangle_dir mangles si
                 call mangle_name                ; Mangle ramdisk name