pxe: Move pxe_utils files

Move the header file into the main include/ directory so we can use it
from the bootmethod code. Move the C file into boot/ since it relates to
booting.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Artem Lapkin <email2tema@gmail.com>
Tested-by: Artem Lapkin <email2tema@gmail.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>

1 files changed, 205 insertions, 0 deletions

diff --git a/include/pxe_utils.h b/include/pxe_utils.h
new file mode 100644
index 00000000000..6681442ea55
--- /dev/null
+++ b/include/pxe_utils.h
@@ -0,0 +1,205 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#ifndef __PXE_UTILS_H
+#define __PXE_UTILS_H
+
+#include <linux/list.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;
+	char *fdtoverlays;
+	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;
+};
+
+struct pxe_context;
+typedef int (*pxe_getfile_func)(struct pxe_context *ctx, const char *file_path,
+				char *file_addr);
+
+/**
+ * struct pxe_context - context information for PXE parsing
+ *
+ * @cmdtp: Pointer to command table to use when calling other commands
+ * @getfile: Function called by PXE to read a file
+ * @userdata: Data the caller requires for @getfile
+ * @allow_abs_path: true to allow absolute paths
+ */
+struct pxe_context {
+	struct cmd_tbl *cmdtp;
+	/**
+	 * getfile() - read a file
+	 *
+	 * @ctx: PXE context
+	 * @file_path: Path to the file
+	 * @file_addr: String containing the hex address to put the file in
+	 *	memory
+	 * Return 0 if OK, -ve on error
+	 */
+	pxe_getfile_func getfile;
+
+	void *userdata;
+	bool allow_abs_path;
+};
+
+/**
+ * destroy_pxe_menu() - Destroy an allocated pxe structure
+ *
+ * Free the memory used by a pxe_menu and its labels
+ *
+ * @cfg: Config to destroy, previous returned from parse_pxefile()
+ */
+void destroy_pxe_menu(struct pxe_menu *cfg);
+
+/**
+ * get_pxe_file() - Read a file
+ *
+ * Retrieve the file at 'file_path' to the locate given by 'file_addr'. If
+ * 'bootfile' was specified in the environment, the path to bootfile will be
+ * prepended to 'file_path' and the resulting path will be used.
+ *
+ * @ctx: PXE context
+ * @file_path: Path to file
+ * @file_addr: Address to place file
+ * Returns 1 on success, or < 0 for error
+ */
+int get_pxe_file(struct pxe_context *ctx, const char *file_path,
+		 ulong file_addr);
+
+/**
+ * get_pxelinux_path() - Read a file from the same place as pxelinux.cfg
+ *
+ * Retrieves a file in the 'pxelinux.cfg' folder. Since this uses get_pxe_file()
+ * to do the hard work, the location of the 'pxelinux.cfg' folder is generated
+ * from the bootfile path, as described in get_pxe_file().
+ *
+ * @ctx: PXE context
+ * @file: Relative path to file
+ * @pxefile_addr_r: Address to load file
+ * Returns 1 on success or < 0 on error.
+ */
+int get_pxelinux_path(struct pxe_context *ctx, const char *file,
+		      ulong pxefile_addr_r);
+
+/**
+ * handle_pxe_menu() - Boot the system as prescribed by a pxe_menu.
+ *
+ * Use the menu system to either get the user's choice or the default, based
+ * on config or user input.  If there is no default or user's choice,
+ * attempted to boot labels in the order they were given in pxe files.
+ * If the default or user's choice fails to boot, attempt to boot other
+ * labels in the order they were given in pxe files.
+ *
+ * If this function returns, there weren't any labels that successfully
+ * booted, or the user interrupted the menu selection via ctrl+c.
+ *
+ * @ctx: PXE context
+ * @cfg: PXE menu
+ */
+void handle_pxe_menu(struct pxe_context *ctx, struct pxe_menu *cfg);
+
+/**
+ * parse_pxefile() - Parsing a pxe file
+ *
+ * This is only used for the top-level file.
+ *
+ * @ctx: PXE context (provided by the caller)
+ * Returns NULL if there is an error, otherwise, returns a pointer to a
+ * pxe_menu struct populated with the results of parsing the pxe file (and any
+ * files it includes). The resulting pxe_menu struct can be free()'d by using
+ * the destroy_pxe_menu() function.
+ */
+struct pxe_menu *parse_pxefile(struct pxe_context *ctx, ulong menucfg);
+
+/**
+ * format_mac_pxe() - Convert a MAC address to PXE format
+ *
+ * Convert an ethaddr from the environment to the format used by pxelinux
+ * filenames based on mac addresses. Convert's ':' to '-', and adds "01-" to
+ * the beginning of the ethernet address to indicate a hardware type of
+ * Ethernet. Also converts uppercase hex characters into lowercase, to match
+ * pxelinux's behavior.
+ *
+ * @outbuf: Buffer to hold the output (must hold 22 bytes)
+ * @outbuf_len: Length of buffer
+ * Returns 1 for success, -ENOENT if 'ethaddr' is undefined in the
+ * environment, or some other value < 0 on error.
+ */
+int format_mac_pxe(char *outbuf, size_t outbuf_len);
+
+/**
+ * pxe_setup_ctx() - Setup a new PXE context
+ *
+ * @ctx: Context to set up
+ * @cmdtp: Command table entry which started this action
+ * @getfile: Function to call to read a file
+ * @userdata: Data the caller requires for @getfile - stored in ctx->userdata
+ * @allow_abs_path: true to allow absolute paths
+ */
+void pxe_setup_ctx(struct pxe_context *ctx, struct cmd_tbl *cmdtp,
+		   pxe_getfile_func getfile, void *userdata,
+		   bool allow_abs_path);
+
+#endif /* __PXE_UTILS_H */