Add localboot API call

3 files changed, 78 insertions, 0 deletions

diff --git a/NEWS b/NEWS
index e38f0b4b..5b1bc034 100644
--- a/NEWS
+++ b/NEWS
@@ -9,6 +9,8 @@ Changes in 3.10:
 	* Fix PCI handing (ethersel etc) on several old chipsets (and
 	  VMWare.)
 	* Try to deal with systems with broken EBIOS.
+	* New API call to do "localboot".
+	* New API call to query features.
 
 Changes in 3.09:
 	* gcc4 compilation fix.
diff --git a/comboot.doc b/comboot.doc
index ee2ca07e..8680b711 100644
--- a/comboot.doc
+++ b/comboot.doc
@@ -460,6 +460,8 @@ AX=000Ch [2.00]	Perform final cleanup
 
 	ISOLINUX:	0000h	Normal cleanup
 
+	EXTLINUX:	0000h	Normal cleanup
+
 	All other values are undefined, and may have different
 	meanings in future versions of SYSLINUX.
 
@@ -583,3 +585,41 @@ AX=0013h [3.08] Idle loop call
 	any periodic activities required by the filesystem code.  At
 	the moment, this is a no-op on all derivatives except
 	PXELINUX, where it executes PXE calls to answer ARP queries.
+
+	Note: it's safe to call this API call on previous SYSLINUX
+	versions (2.00 or later); it will just harmlessly fail.  If
+	API call INT 22h, AX=0015h, bit 1 is set, there is no reason
+	(but safe) to call this routine.
+
+
+AX=0014h [3.10] Local boot [PXELINUX, ISOLINUX]
+	Input:	AX	0014h
+		DX	Local boot parameter
+	Output:	Does not return
+
+	This function invokes the equivalent of the "localboot"
+	configuration file option.  The parameter in DX is the same
+	parameter as would be entered after "localboot" in the
+	configuration file; this parameter is derivative-specific --
+	see syslinux.doc for the definition.
+
+
+AX=0015h [3.10] Get feature flags
+	Input:	AX	0015h
+	Output:	ES:BX	pointer to flags in memory
+		CX	number of flag bytes
+
+	This function reports whether or not this SYSLINUX version and
+	derivative supports specific features.  Keep in mind that
+	future versions might have more bits; remember to treat any
+	bits beyond the end of the array (as defined by the value in
+	CX) as zero.
+
+	Currently the following feature flag is defined:
+
+	Byte	Bit	Definition
+	----------------------------------------------------
+	0	0	Local boot (AX=0014h) supported
+		1	Idle loop call (AX=0013h) is a no-op
+
+	All other flags are reserved.
diff --git a/comboot.inc b/comboot.inc
index dfe57b64..a0651928 100644
--- a/comboot.inc
+++ b/comboot.inc
@@ -652,6 +652,28 @@ comapi_idle:
 		clc
 		ret
 
+;
+; INT 22h AX=0014h	Local boot
+;
+%if IS_PXELINUX || IS_ISOLINUX
+comapi_localboot:
+		mov ax,P_DX
+		jmp local_boot
+%else
+comapi_localboot equ comapi_err
+%endif
+
+;
+; INT 22h AX=0015h	Feature flags
+;
+comapi_features:
+		mov P_ES,cs
+		mov P_BX,feature_flags
+		mov P_CX,feature_flags_len
+		clc
+		ret
+
+		section .data
 int21_table:
 		int21	00h, comboot_return
 		int21	01h, comboot_getkey
@@ -687,7 +709,21 @@ int22_table:
 		dw comapi_maxshuffle	; 0011 maximum shuffle descriptors
 		dw comapi_shuffle	; 0012 cleanup, shuffle and boot
 		dw comapi_idle		; 0013 idle call
+		dw comapi_localboot	; 0014 local boot
+		dw comapi_features	; 0015 feature flags
 int22_count	equ ($-int22_table)/2
 
 APIKeyWait	db 0
 APIKeyFlag	db 0
+
+;
+; This is the feature flag array for INT 22h AX=0015h
+feature_flags:
+%if IS_PXELINUX
+		db 1			; Have local boot, idle not noop
+%elif IS_ISOLINUX
+		db 3			; Have local boot, idle is noop
+%else
+		db 2			; No local boot, idle is noop
+%endif
+feature_flags_len equ ($-feature_flags)