[pxeprefix] Fetch command line (if any) via PXENV_FILE_CMDLINE

Use PXENV_FILE_CMDLINE to retrieve the command line (if any) provided
by the invoking PXE stack.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/arch/i386/prefix/pxeprefix.S b/src/arch/i386/prefix/pxeprefix.S
index 9ccc4a2b519a31fd19a1dcbfb9d29a4b1b2d9b73..3c851dca131bb60cc6f24784bc3818da574541a3 100644 (file)
--- a/src/arch/i386/prefix/pxeprefix.S
+++ b/src/arch/i386/prefix/pxeprefix.S
@@ -5,6 +5,7 @@ FILE_LICENCE ( GPL2_OR_LATER )
 #define PXENV_UNDI_GET_IFACE_INFO      0x0013
 #define        PXENV_STOP_UNDI                 0x0015
 #define PXENV_UNLOAD_STACK             0x0070
+#define PXENV_FILE_CMDLINE             0x00e8
 
 #define PXE_HACK_EB54                  0x0001
 
@@ -381,6 +382,37 @@ get_iface_type:
 99:    movb    $0x0a, %al
        call    print_character
 
+
+/*****************************************************************************
+ * Check for a command line
+ *****************************************************************************
+ */
+get_cmdline:
+       /* Issue PXENV_FILE_CMDLINE */
+       xorl    %esi, %esi
+       movw    %ss, %si
+       movw    %si, ( pxe_parameter_structure + 0x06 )
+       movw    $PREFIX_STACK_SIZE, ( pxe_parameter_structure + 0x04 )
+       movw    $0xffff, ( pxe_parameter_structure + 0x02 )
+       movw    $PXENV_FILE_CMDLINE, %bx
+       call    pxe_call
+       jnc     1f
+       call    print_pxe_error
+       jmp     99f
+1:     /* Check for non-NULL command line */
+       movw    ( pxe_parameter_structure + 0x02 ), %ax
+       testw   %ax, %ax
+       jz      99f
+       /* Record command line */
+       shll    $4, %esi
+       addl    $PREFIX_STACK_SIZE, %esi
+       movl    %esi, pxe_cmdline
+99:
+       .section ".prefix.data", "aw", @progbits
+pxe_cmdline:
+       .long   0
+       .previous
+
 /*****************************************************************************
  * Leave NIC in a safe state
  *****************************************************************************
@@ -728,6 +760,9 @@ run_ipxe:
        movw    pxe_ss, %di
        movl    pxe_esp, %ebp
 
+       /* Retrieve PXE command line, if any */
+       movl    pxe_cmdline, %esi
+
        /* Jump to .text16 segment with %ds pointing to .data16 */
        movw    %bx, %ds
        pushw   %ax
@@ -738,6 +773,9 @@ run_ipxe:
        /* Update the exit hook */
        movw    %cs, ( pxe_exit_hook + 2 )
 
+       /* Store command-line pointer */
+       movl    %esi, cmdline_phys
+
        /* Run main program */
        pushl   $main
        pushw   %cs