PXELINUX: When doing a gPXE FILE_READ, actually handle errors

If gPXE FILE_READ returns an actual error, don't loop forever.

diff --git a/pxelinux.asm b/pxelinux.asm
index 6a57966..b3f1cbb 100644 (file)
--- a/pxelinux.asm
+++ b/pxelinux.asm
@@ -2019,15 +2019,17 @@ get_packet_gpxe:
                mov word [di+4],PKTBUF_SIZE
                mov bx,PXENV_FILE_READ
                call pxenv
-               ; XXX: FIX THIS: Need to be able to distinguish
-               ; error, EOF, and no data
-               jc .again
+               jnc .ok                         ; Got data or EOF
+               cmp word [di],PXENV_STATUS_TFTP_OPEN    ; == EWOULDBLOCK
+               je .again
+               jmp kaboom                      ; Otherwise error...
 
+.ok:
                movzx eax,word [di+4]           ; Bytes read
                mov [si+tftp_bytesleft],ax      ; Bytes in buffer
                add [si+tftp_filepos],eax       ; Position in file
 
-               and ax,ax
+               and ax,ax                       ; EOF?
                mov eax,[si+tftp_filepos]
 
                jnz .got_stuff