[PATCH 4/7] pxe_utils: export per-entry label helpers

[Alexey Charkov <alchark@flipper.net>]

Drop the static qualifier from label_create(), label_destroy(),
parse_label_keys() and label_boot(), and declare them in
<pxe_utils.h> to make them reusable.

The intended consumer is a Boot Loader Specification bootmeth, where
each on-disk file under loader/entries/ is a single entry with no
'label' header and no menu to traverse: the bootmeth derives the
label name from the filename, hands the file body to
parse_label_keys(), and invokes label_boot() directly.

No behaviour change: the implementations are unchanged and existing
in-tree callers in pxe_utils.c continue to use them as before.

Signed-off-by: Alexey Charkov <alchark@flipper.net>
---
 boot/pxe_utils.c    | 37 ++++-------------------------------
 include/pxe_utils.h | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 33 deletions(-)

diff --git a/boot/pxe_utils.c b/boot/pxe_utils.c
index 420cee307baf..6dad3045f9d4 100644
--- a/boot/pxe_utils.c
+++ b/boot/pxe_utils.c
@@ -218,15 +218,7 @@ static int get_relfile_envaddr(struct pxe_context *ctx, const char *file_path,
 	return get_relfile(ctx, file_path, file_addr, type, filesizep);
 }
 
-/**
- * label_create() - crate a new PXE label
- *
- * Allocates memory for and initializes a pxe_label. This uses malloc, so the
- * result must be free()'d to reclaim the memory.
- *
- * Returns a pointer to the label, or NULL if out of memory
- */
-static struct pxe_label *label_create(void)
+struct pxe_label *label_create(void)
 {
 	struct pxe_label *label;
 
@@ -239,20 +231,7 @@ static struct pxe_label *label_create(void)
 	return label;
 }
 
-/**
- * label_destroy() - free the memory used by a pxe_label
- *
- * This frees @label itself as well as memory used by its name,
- * kernel, config, append, initrd, fdt, fdtdir and fdtoverlay members, if
- * they're non-NULL.
- *
- * So - be sure to only use dynamically allocated memory for the members of
- * the pxe_label struct, unless you want to clean it up first. These are
- * currently only created by the pxe file parsing code.
- *
- * @label: Label to free
- */
-static void label_destroy(struct pxe_label *label)
+void label_destroy(struct pxe_label *label)
 {
 	free(label->name);
 	free(label->kernel_label);
@@ -542,7 +521,7 @@ cleanup:
  * Returns does not return on success, otherwise returns 0 if a localboot
  *	label was processed, or 1 on error
  */
-static int label_boot(struct pxe_context *ctx, struct pxe_label *label)
+int label_boot(struct pxe_context *ctx, struct pxe_label *label)
 {
 	char *bootm_argv[] = { "bootm", NULL, NULL, NULL, NULL };
 	char *zboot_argv[] = { "zboot", NULL, "0", NULL, NULL };
@@ -1287,15 +1266,7 @@ static int parse_label_kernel(char **c, struct pxe_label *label)
 	return 1;
 }
 
-/*
- * Parse the body of a label: the sequence of key/value lines that follow
- * the 'label NAME' header. Stops at end-of-file or at a token that doesn't
- * belong inside a label (which is pushed back so the caller can handle it).
- *
- * Returns 1 on success, < 0 on error.
- */
-static int parse_label_keys(char **c, struct pxe_menu *cfg,
-			    struct pxe_label *label)
+int parse_label_keys(char **c, struct pxe_menu *cfg, struct pxe_label *label)
 {
 	struct token t;
 	char *s;
diff --git a/include/pxe_utils.h b/include/pxe_utils.h
index 0378f2889f7b..e639e59e5dc8 100644
--- a/include/pxe_utils.h
+++ b/include/pxe_utils.h
@@ -202,6 +202,62 @@ void handle_pxe_menu(struct pxe_context *ctx, struct pxe_menu *cfg);
  */
 struct pxe_menu *parse_pxefile(struct pxe_context *ctx, ulong menucfg);
 
+/**
+ * label_create() - Allocate and zero-initialise a struct pxe_label
+ *
+ * The result must be freed with label_destroy().
+ *
+ * Return: pointer to the new label, or NULL if out of memory
+ */
+struct pxe_label *label_create(void);
+
+/**
+ * label_destroy() - Free a struct pxe_label and its string members
+ *
+ * Frees @label as well as memory used by its name, kernel, config, append,
+ * initrd, fdt, fdtdir and fdtoverlays members, if they are non-NULL. All
+ * such members must therefore reference malloc()'d memory.
+ *
+ * @label: Label to free
+ */
+void label_destroy(struct pxe_label *label);
+
+/**
+ * parse_label_keys() - Parse the body of a label
+ *
+ * Walks the sequence of key/value lines that follow a 'label NAME' header,
+ * populating @label. Stops at end-of-file or at a token that does not
+ * belong inside a label (which is pushed back so the caller can handle it).
+ *
+ * This is exported so that callers handling formats which lack a 'label'
+ * header (e.g. Boot Loader Specification type #2 entry files) can populate
+ * a pre-created label directly from a file body.
+ *
+ * @c: Pointer to the cursor into the file being parsed; updated on return
+ * @cfg: Menu the label belongs to (used for 'menu default' bookkeeping)
+ * @label: Label to populate; must already be allocated and (when called for
+ *	a file that has a 'label' header) attached to @cfg->labels
+ * Return: 1 on success, < 0 on error
+ */
+int parse_label_keys(char **c, struct pxe_menu *cfg, struct pxe_label *label);
+
+/**
+ * label_boot() - Boot according to the contents of a single pxe_label
+ *
+ * On success this function does not return; on failure it returns to
+ * let the caller try a different label or surface an error.
+ *
+ * The kernel is staged at $kernel_addr_r, an optional initrd at
+ * $ramdisk_addr_r, and an optional FDT at $fdt_addr_r. If the label
+ * has an 'append' string it overwrites $bootargs.
+ *
+ * @ctx: PXE context
+ * @label: Label to boot
+ * Return: does not return on success; 0 if a 'localboot' label was
+ *	processed; 1 on error
+ */
+int label_boot(struct pxe_context *ctx, struct pxe_label *label);
+
 /**
  * format_mac_pxe() - Convert a MAC address to PXE format
  *

-- 
2.53.0