[pxe] Add PXENV_FILE_CMDLINE API call

Allow a PXE NBP to obtain its command line (if any) via the new PXE
API call PXENV_FILE_CMDLINE.

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

src/arch/i386/image/pxe_image.c

 
 FEATURE ( FEATURE_IMAGE, "PXE", DHCP_EB_FEATURE_PXE, 1 );
 
+/** PXE command line */
+const char *pxe_cmdline;
+
 /**
  * Execute PXE image
  *
 	/* Activate PXE */
 	pxe_activate ( netdev );
 
+	/* Set PXE command line */
+	pxe_cmdline = image->cmdline;
+
 	/* Start PXE NBP */
 	rc = pxe_start_nbp();
 
+	/* Clear PXE command line */
+	pxe_cmdline = NULL;
+
 	/* Deactivate PXE */
 	pxe_deactivate();
 

src/arch/i386/include/pxe.h

 	( ( 'P' << 0 ) + ( 'C' << 8 ) + ( 'I' << 16 ) + ( 'R' << 24 ) )
 
 extern struct net_device *pxe_netdev;
+extern const char *pxe_cmdline;
 
 extern void pxe_set_netdev ( struct net_device *netdev );
 extern PXENV_EXIT_t pxenv_tftp_read_file ( struct s_PXENV_TFTP_READ_FILE

src/arch/i386/include/pxe_api.h

 
 /** @} */ /* pxenv_file_exit_hook */
 
+/** @defgroup pxenv_file_cmdline PXENV_FILE_CMDLINE
+ *
+ * FILE CMDLINE
+ *
+ * @{
+ */
+
+/** PXE API function code for pxenv_file_cmdline() */
+#define PXENV_FILE_CMDLINE			0x00e8
+
+/** Parameter block for pxenv_file_cmdline() */
+struct s_PXENV_FILE_CMDLINE {
+	PXENV_STATUS_t Status;		/**< PXE status code */
+	UINT16_t BufferSize;		/**< Data buffer size */
+	SEGOFF16_t Buffer;		/**< Data buffer */
+} __attribute__ (( packed ));
+
+typedef struct s_PXENV_FILE_CMDLINE PXENV_FILE_CMDLINE_t;
+
+/** @} */ /* pxe_file_cmdline */
+
 /** @} */ /* pxe_file_api */
 
 /** @defgroup pxe_loader_api PXE Loader API

src/arch/i386/interface/pxe/pxe_file.c

 	return PXENV_EXIT_SUCCESS;
 }
 
+/**
+ * FILE CMDLINE
+ *
+ * @v file_cmdline			Pointer to a struct s_PXENV_FILE_CMDLINE
+ * @v s_PXENV_FILE_CMDLINE::Buffer	Buffer to contain command line
+ * @v s_PXENV_FILE_CMDLINE::BufferSize	Size of buffer
+ * @ret #PXENV_EXIT_SUCCESS		Command was executed successfully
+ * @ret #PXENV_EXIT_FAILURE		Command was not executed successfully
+ * @ret s_PXENV_FILE_EXEC::Status	PXE status code
+ * @ret s_PXENV_FILE_EXEC::BufferSize	Length of command line (including NUL)
+ *
+ */
+static PXENV_EXIT_t
+pxenv_file_cmdline ( struct s_PXENV_FILE_CMDLINE *file_cmdline ) {
+	userptr_t buffer;
+	size_t max_len;
+	size_t len;
+
+	DBG ( "PXENV_FILE_CMDLINE to %04x:%04x+%04x \"%s\"\n",
+	      file_cmdline->Buffer.segment, file_cmdline->Buffer.offset,
+	      file_cmdline->BufferSize, pxe_cmdline );
+
+	buffer = real_to_user ( file_cmdline->Buffer.segment,
+				file_cmdline->Buffer.offset );
+	len = file_cmdline->BufferSize;
+	max_len = ( pxe_cmdline ?
+		    ( strlen ( pxe_cmdline ) + 1 /* NUL */ ) : 0 );
+	if ( len > max_len )
+		len = max_len;
+	copy_to_user ( buffer, 0, pxe_cmdline, len );
+	file_cmdline->BufferSize = max_len;
+
+	file_cmdline->Status = PXENV_STATUS_SUCCESS;
+	return PXENV_EXIT_SUCCESS;
+}
+
 /**
  * FILE API CHECK
  *
 		       struct s_PXENV_GET_FILE_SIZE ),
 	PXE_API_CALL ( PXENV_FILE_EXEC, pxenv_file_exec,
 		       struct s_PXENV_FILE_EXEC ),
+	PXE_API_CALL ( PXENV_FILE_CMDLINE, pxenv_file_cmdline,
+		       struct s_PXENV_FILE_CMDLINE ),
 	PXE_API_CALL ( PXENV_FILE_API_CHECK, pxenv_file_api_check,
 		       struct s_PXENV_FILE_API_CHECK ),
 };