cmd: Prepare sysboot command independence

As sysboot and pxe commands are sharing piece of code, migrate this
common code into a new file pxe_utils.c to prepare sysboot command
code extraction from pxe.c

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>

cmd/Makefile

@@ -111,7 +111,7 @@ ifdef CONFIG_PCI
 obj-$(CONFIG_CMD_PCI) += pci.o
 endif
 obj-$(CONFIG_CMD_PINMUX) += pinmux.o
-obj-$(CONFIG_CMD_PXE) += pxe.o
+obj-$(CONFIG_CMD_PXE) += pxe.o pxe_utils.o
 obj-$(CONFIG_CMD_WOL) += wol.o
 obj-$(CONFIG_CMD_QFW) += qfw.o
 obj-$(CONFIG_CMD_READ) += read.o

cmd/pxe_utils.h

+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#ifndef __PXE_UTILS_H
+#define __PXE_UTILS_H
+
+/*
+ * A note on the pxe file parser.
+ *
+ * We're parsing files that use syslinux grammar, which has a few quirks.
+ * String literals must be recognized based on context - there is no
+ * quoting or escaping support. There's also nothing to explicitly indicate
+ * when a label section completes. We deal with that by ending a label
+ * section whenever we see a line that doesn't include.
+ *
+ * As with the syslinux family, this same file format could be reused in the
+ * future for non pxe purposes. The only action it takes during parsing that
+ * would throw this off is handling of include files. It assumes we're using
+ * pxe, and does a tftp download of a file listed as an include file in the
+ * middle of the parsing operation. That could be handled by refactoring it to
+ * take a 'include file getter' function.
+ */
+
+/*
+ * Describes a single label given in a pxe file.
+ *
+ * Create these with the 'label_create' function given below.
+ *
+ * name - the name of the menu as given on the 'menu label' line.
+ * kernel - the path to the kernel file to use for this label.
+ * append - kernel command line to use when booting this label
+ * initrd - path to the initrd to use for this label.
+ * attempted - 0 if we haven't tried to boot this label, 1 if we have.
+ * localboot - 1 if this label specified 'localboot', 0 otherwise.
+ * list - lets these form a list, which a pxe_menu struct will hold.
+ */
+struct pxe_label {
+	char num[4];
+	char *name;
+	char *menu;
+	char *kernel;
+	char *config;
+	char *append;
+	char *initrd;
+	char *fdt;
+	char *fdtdir;
+	int ipappend;
+	int attempted;
+	int localboot;
+	int localboot_val;
+	struct list_head list;
+};
+
+/*
+ * Describes a pxe menu as given via pxe files.
+ *
+ * title - the name of the menu as given by a 'menu title' line.
+ * default_label - the name of the default label, if any.
+ * bmp - the bmp file name which is displayed in background
+ * timeout - time in tenths of a second to wait for a user key-press before
+ *           booting the default label.
+ * prompt - if 0, don't prompt for a choice unless the timeout period is
+ *          interrupted.  If 1, always prompt for a choice regardless of
+ *          timeout.
+ * labels - a list of labels defined for the menu.
+ */
+struct pxe_menu {
+	char *title;
+	char *default_label;
+	char *bmp;
+	int timeout;
+	int prompt;
+	struct list_head labels;
+};
+
+extern bool is_pxe;
+
+extern int (*do_getfile)(cmd_tbl_t *cmdtp, const char *file_path,
+			 char *file_addr);
+void destroy_pxe_menu(struct pxe_menu *cfg);
+int get_pxe_file(cmd_tbl_t *cmdtp, const char *file_path,
+		 unsigned long file_addr);
+int get_pxelinux_path(cmd_tbl_t *cmdtp, const char *file,
+		      unsigned long pxefile_addr_r);
+void handle_pxe_menu(cmd_tbl_t *cmdtp, struct pxe_menu *cfg);
+struct pxe_menu *parse_pxefile(cmd_tbl_t *cmdtp, unsigned long menucfg);
+int format_mac_pxe(char *outbuf, size_t outbuf_len);
+
+#endif /* __PXE_UTILS_H */