[romprefix] Add vendor branding facilities and guidelines

Some hardware vendors have been known to remove all gPXE-related
branding from ROMs that they build.  While this is not prohibited by
the GPL, it is a little impolite.

Add a facility for adding branding messages via two #defines
(PRODUCT_NAME and PRODUCT_SHORT_NAME) in config/general.h.  This
should accommodate all known OEM-mandated branding requirements.
Vendors with branding requirements that cannot be satisfied by using
PRODUCT_NAME and/or PRODUCT_SHORT_NAME should contact us so that we
can extended this facility as necessary.

src/arch/i386/prefix/libprefix.S

 	ret
 	.size	print_pci_busdevfn, . - print_pci_busdevfn
 
+/*****************************************************************************
+ * Utility function: clear current line
+ *
+ * Parameters:
+ *   %ds:di : output buffer (or %di=0 to print to console)
+ * Returns:
+ *   %ds:di : next character in output buffer (if applicable)
+ *****************************************************************************
+ */
+	.section ".prefix.lib"
+	.code16
+	.globl	print_kill_line
+print_kill_line:
+	/* Preserve registers */
+	pushw	%ax
+	pushw	%cx
+	/* Print CR */
+	movb	$'\r', %al
+	call	print_character
+	/* Print 79 spaces */
+	movb	$' ', %al
+	movw	$79, %cx
+1:	call	print_character
+	loop	1b
+	/* Print CR */
+	movb	$'\r', %al
+	call	print_character
+	/* Restore registers and return */
+	popw	%cx
+	popw	%ax
+	ret
+	.size	print_kill_line, . - print_kill_line
+
 /****************************************************************************
  * pm_call (real-mode near call)
  *

src/arch/i386/prefix/romprefix.S

 
 /* Product string
  *
- * Defaults to "gPXE".  If the ROM image is writable at initialisation
- * time, it will be filled in to include the PCI bus:dev.fn number of
- * the card as well.
+ * Defaults to PRODUCT_SHORT_NAME.  If the ROM image is writable at
+ * initialisation time, it will be filled in to include the PCI
+ * bus:dev.fn number of the card as well.
  */
 prodstr:
-	.ascii	"gPXE"
+	.ascii	PRODUCT_SHORT_NAME
 prodstr_separator:
 	.byte	0
 	.ascii	"(PCI "
 	movw	$init_message_prompt, %si
 	xorw	%di, %di
 	call	print_message
+	movw	$prodstr, %si
+	call	print_message
+	movw	$init_message_dots, %si
+	call	print_message
 	/* Wait for Ctrl-B */
 	movw	$0xff02, %bx
 	call	wait_for_key
 	/* Clear prompt */
 	pushf
-	movw	$clear_message, %si
 	xorw	%di, %di
+	call	print_kill_line
+	movw	$init_message_done, %si
 	call	print_message
 	popf
-	jnz	1f
+	jnz	2f
 	/* Ctrl-B was pressed: invoke gPXE.  The keypress will be
 	 * picked up by the initial shell prompt, and we will drop
 	 * into a shell.
 	 */
 	pushw	%cs
 	call	exec
-1:
+2:
 	/* Restore registers */
 	popw	%gs
 	popw	%fs
 	lret
 	.size init, . - init
 
+/*
+ * Note to hardware vendors:
+ *
+ * If you wish to brand this boot ROM, please do so by defining the
+ * strings PRODUCT_NAME and PRODUCT_SHORT_NAME in config/general.h.
+ *
+ * While nothing in the GPL prevents you from removing all references
+ * to gPXE or http://etherboot.org, we prefer you not to do so.
+ *
+ * If you have an OEM-mandated branding requirement that cannot be
+ * satisfied simply by defining PRODUCT_NAME and PRODUCT_SHORT_NAME,
+ * please contact us.
+ *
+ * [ Including an ASCII NUL in PRODUCT_NAME is considered to be
+ *   bypassing the spirit of this request! ]
+ */
 init_message:
+	.ascii	"\n"
+	.ascii	PRODUCT_NAME
+	.ascii	"\n"
 	.asciz	"gPXE (http://etherboot.org) - "
 	.size	init_message, . - init_message
 init_message_pci:
 	.asciz	" INT19"
 	.size	init_message_int19, . - init_message_int19
 init_message_prompt:
-	.asciz	"\nPress Ctrl-B to configure gPXE..."
+	.asciz	"\nPress Ctrl-B to configure "
 	.size	init_message_prompt, . - init_message_prompt
-clear_message:
-	.asciz	"\r                                          \n\n"
-	.size	clear_message, . - clear_message
+init_message_dots:
+	.asciz	"..."
+	.size	init_message_dots, . - init_message_dots
+init_message_done:
+	.asciz	"\n\n"
+	.size	init_message_done, . - init_message_done
 
 /* ROM image location
  *
 	movw	$0xdf42, %bx
 	call	wait_for_key
 	pushf
-	movw	$clear_message, %si
 	xorw	%di, %di
+	call	print_kill_line
+	movw	$int19_message_done, %si
 	call	print_message
 	popf
 	jnz	1f
 int19_message_dots:
 	.asciz	"..."
 	.size	int19_message_dots, . - int19_message_dots
+int19_message_done:
+	.asciz	"\n\n"
+	.size	int19_message_done, . - int19_message_done
 	
 /* Execute as a boot device
  *

src/config/general.h

 
 #include <config/defaults.h>
 
+/*
+ * Branding
+ *
+ * Vendors may use these strings to add their own branding to gPXE.
+ * PRODUCT_NAME is displayed prior to any gPXE branding in startup
+ * messages, and PRODUCT_SHORT_NAME is used where a brief product
+ * label is required (e.g. in BIOS boot selection menus).
+ *
+ * To minimise end-user confusion, it's probably a good idea to either
+ * make PRODUCT_SHORT_NAME a substring of PRODUCT_NAME or leave it as
+ * "gPXE".
+ *
+ */
+#define PRODUCT_NAME ""
+#define PRODUCT_SHORT_NAME "gPXE"
+
 /*
  * Timer configuration
  *

src/core/main.c

 #include <gpxe/shell.h>
 #include <gpxe/shell_banner.h>
 #include <usr/autoboot.h>
+#include <config/general.h>
 
 #define NORMAL	"\033[0m"
 #define BOLD	"\033[1m"
 	initialise();
 	startup();
 
-	/* Print welcome banner */
-	printf ( NORMAL "\n\n\n" BOLD "gPXE " VERSION
+	/*
+	 * Print welcome banner
+	 *
+	 *
+	 * If you wish to brand this build of gPXE, please do so by
+	 * defining the string PRODUCT_NAME in config/general.h.
+	 *
+	 * While nothing in the GPL prevents you from removing all
+	 * references to gPXE or http://etherboot.org, we prefer you
+	 * not to do so.
+	 *
+	 */
+	printf ( NORMAL "\n\n" PRODUCT_NAME "\n" BOLD "gPXE " VERSION
 		 NORMAL " -- Open Source Boot Firmware -- "
 		 CYAN "http://etherboot.org" NORMAL "\n"
 		 "Features:" );