Query once based on MAC address.

diff --git a/NEWS b/NEWS
index ab64e5d..1fb24a3 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,11 @@ apply to that specific program only; other changes apply to all of
 them.
 
 Changes in 2.05:
+       * PXELINUX: Add a default query based on the hardware address
+         of the boot device.  This is in lower case hexadecimal form
+         separated by dashes and including the hardware type, for
+         example, the Ethernet (type 1) address 88:99:AA:BB:CC:DD
+         would query the file pxelinux.cfg/01-88-99-aa-bb-cc-dd.
 
 Changes in 2.04:
        * ALL: Reclaim even more low memory by observing that

diff --git a/pxelinux.asm b/pxelinux.asm
index 9bba119..184cd7d 100644 (file)
--- a/pxelinux.asm
+++ b/pxelinux.asm
@@ -203,6 +203,10 @@ NumBuf             resb 15                 ; Buffer to load number
 NumBufEnd      resb 1                  ; Last byte in NumBuf
 DotQuadBuf     resb 16                 ; Buffer for dotted-quad IP address
 IPOption       resb 80                 ; ip= option buffer
+MACLen         resb 1                  ; MAC address len
+MACType                resb 1                  ; MAC address type
+MAC            resb 16                 ; Actual MAC address
+MACStr         resb 51                 ; MAC address as a string
                alignb 32
 KernelName      resb FILENAME_MAX       ; Mangled name for kernel
 KernelCName     resb FILENAME_MAX      ; Unmangled kernel name
@@ -598,6 +602,44 @@ query_bootp:
                pop cx                          ; Forget status
                mov cx,[pxe_bootp_query_pkt_2.buffersize]
                call parse_dhcp                 ; Parse DHCP packet
+;
+; Save away MAC address (assume this is in query info 2.  If this
+; turns out to be problematic it might be better getting it from
+; the query info 1 packet.)
+;
+.save_mac:
+               movzx cx,byte [trackbuf+bootp.hardlen]
+               mov [MACLen],cl
+               mov al,[trackbuf+bootp.hardware]
+               mov [MACType],al
+               mov si,trackbuf+bootp.macaddr
+               mov di,MAC
+               push cx
+               rep movsb
+               mov cx,MAC+16
+               sub cx,di
+               xor ax,ax
+               rep stosb
+               pop cx
+               
+               mov si,MACType
+               mov di,MACStr
+               inc cx
+               mov bx,hextbl_lower
+.hexify_mac:
+               lodsb
+               mov ah,al
+               shr al,4
+               xlatb
+               stosb
+               mov al,ah
+               and al,0Fh
+               xlatb
+               stosb
+               mov al,'-'
+               stosb
+               loop .hexify_mac
+               mov [di-1],byte 0               ; Null-terminate and strip final colon
 
 ;
 ; Now, get the boot file and other info.  This lives in the CACHED_REPLY
@@ -644,9 +686,9 @@ query_bootp:
                call writestr
                call crlf
 
-               mov si,IPOption                 ; ***
-               call writestr                   ; ***
-               call crlf                       ; ***
+               mov si,IPOption
+               call writestr
+               call crlf
 
 ;
 ; Check to see if we got any PXELINUX-specific DHCP options; in particular,
@@ -747,27 +789,11 @@ prefix:           test byte [DHCPMagic], 04h      ; Did we get a path prefix option
 ;
 ; Load configuration file
 ;
-find_config:   mov di,trackbuf
+find_config:
+               mov di,trackbuf
                mov si,cfgprefix
                mov cx,cfgprefix_len
                rep movsb
-               mov cx,8
-               mov eax,[MyIP]
-               xchg ah,al                      ; Convert to host byte order
-               ror eax,16
-               xchg ah,al
-.hexify_loop:  rol eax,4
-               push eax
-               and al,0Fh
-               cmp al,10
-               jae .high
-.low:          add al,'0'
-               jmp short .char
-.high:         add al,'A'-10
-.char:         stosb
-               pop eax
-               loop .hexify_loop
-
 ;
 ; Begin looking for configuration file
 ;
@@ -787,7 +813,39 @@ config_scan:
                pop di
                jnz .success
 
-.no_option:            ; Have to guess config file name
+.no_option:    ; Have to guess config file name
+               ; Try loading by MAC address
+               push di
+               mov si,MACStr
+               mov cx,(3*17+1)/2
+               rep movsw
+               mov si,trying_msg
+               call writestr
+               mov di,trackbuf
+               mov si,di
+               call writestr
+               call crlf
+               call open
+               pop di
+               jnz .success
+
+.scan_ip:
+               mov cx,8
+               mov eax,[MyIP]
+               xchg ah,al                      ; Convert to host byte order
+               ror eax,16
+               xchg ah,al
+.hexify_loop:  rol eax,4
+               push eax
+               and al,0Fh
+               cmp al,10
+               jae .high
+.low:          add al,'0'
+               jmp short .char
+.high:         add al,'A'-10
+.char:         stosb
+               pop eax
+               loop .hexify_loop
 
                mov cx,9                        ; Up to 9 attempts
 
@@ -2203,6 +2261,7 @@ LF                equ 10          ; Line Feed
 FF             equ 12          ; Form Feed
 BS             equ  8          ; Backspace
 
+hextbl_lower   db '0123456789abcdef'
 copyright_str   db ' Copyright (C) 1994-', year, ' H. Peter Anvin'
                db CR, LF, 0
 boot_prompt    db 'boot: ', 0