Changeset 1d8b222c5fa8996b5d46ae8224e3331f31f5fb5b for core/pxelinux.asm

Timestamp:

10/05/09 22:06:06 (3 years ago)

Author:

H. Peter Anvin <hpa@…>

Children:

fee688790af77e282a3d04c9fb061089ec16a502

Parents:

00d897e58126a7f12990dda8b07266ab12e853b8

git-committer:

H. Peter Anvin <hpa@zytor.com> / 2009-10-05T15:06:06Z-0700

Message:

pxelinux: handle hardcoded options both "before" and "after" DHCP

Make it possible to specify hardcoded options both "before" and
"after" the processing of DHCP/PXE options.

Signed-off-by: H. Peter Anvin <hpa@…>

Files:

• core/pxelinux.asm (modified) (7 diffs)

core/pxelinux.asm

@@ -234 +234 @@
 
 hcdhcp_magic    dd 0x2983c8ac           ; Magic number
-                dd 5*4                  ; Size of this structure
-hcdhcp_offset   dd 0                    ; Offset (entered by patcher)
-hcdhcp_len      dd 0                    ; Length (entered by patcher)
+hcdhcp_len      dd 7*4                  ; Size of this structure
 hcdhcp_flags    dd 0                    ; Reserved for the future
+                ; Parameters to be parsed before the ones from PXE
+bdhcp_offset    dd 0                    ; Offset (entered by patcher)
+bdhcp_len       dd 0                    ; Length (entered by patcher)
+                ; Parameters to be parsed *after* the ones from PXE
+adhcp_offset    dd 0                    ; Offset (entered by patcher)
+adhcp_len       dd 0                    ; Length (entered by patcher)
 
 _start1:
@@ -269 +273 @@
 ; Move the hardwired DHCP options (if present) to a safe place...
 ;
-hcdhcp_copy:
-                mov cx,[hcdhcp_len]
-                mov ax,trackbufsize
+bdhcp_copy:
+                mov cx,[bdhcp_len]
+                mov ax,trackbufsize/2
                 jcxz .none
                 cmp cx,ax
                 jbe .oksize
                 mov cx,ax
-                mov [hcdhcp_len],ax
+                mov [bdhcp_len],ax
 .oksize:
-                mov eax,[hcdhcp_offset]
+                mov eax,[bdhcp_offset]
                 add eax,_start
                 mov si,ax
@@ -286 +290 @@
                 mov ds,ax
                 mov di,trackbuf
+                add cx,3
+                shr cx,2
+                rep movsd
+                pop ds
+.none:
+
+adhcp_copy:
+                mov cx,[adhcp_len]
+                mov ax,trackbufsize/2
+                jcxz .none
+                cmp cx,ax
+                jbe .oksize
+                mov cx,ax
+                mov [adhcp_len],ax
+.oksize:
+                mov eax,[adhcp_offset]
+                add eax,_start
+                mov si,ax
+                and si,000Fh
+                shr eax,4
+                push ds
+                mov ds,ax
+                mov di,trackbuf+trackbufsize/2
                 add cx,3
                 shr cx,2
@@ -578 +605 @@
 ; an option field.
 ;
-                mov cx,[hcdhcp_len]
+                mov cx,[bdhcp_len]
                 mov si,trackbuf
                 call parse_dhcp_options
@@ -635 +662 @@
                 call parse_dhcp                 ; Parse DHCP packet
                 call crlf
+
+;
+; Process any hardwired options the user may have specified.  This is
+; different than the actual packets in that there is no header, just
+; an option field.  This handles the "after" options
+;
+                mov cx,[adhcp_len]
+                mov si,trackbuf+trackbufsize/2
+                call parse_dhcp_options
 
 ;
@@ -2300 +2336 @@
 ;
 ; Get a DHCP packet from the PXE stack into the trackbuf.
+; Leaves the upper half of the trackbuf untouched.
 ;
 ; Input:
@@ -2320 +2357 @@
                 movzx ax,dl
                 stosw           ; Packet type
-                mov ax,trackbufsize
+                mov ax,trackbufsize/2
                 stosw           ; Buffer size
                 mov ax,trackbuf