[efi] Add efi_asprintf() and efi_vasprintf()

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

3 files changed, 47 insertions, 0 deletions

diff --git a/src/include/ipxe/efi/efi_strings.h b/src/include/ipxe/efi/efi_strings.h
index a8ace45..a7adff8 100644
--- a/src/include/ipxe/efi/efi_strings.h
+++ b/src/include/ipxe/efi/efi_strings.h
@@ -19,6 +19,8 @@ extern int efi_vssnprintf ( wchar_t *wbuf, ssize_t swsize, const char *fmt,
 			    va_list args );
 extern int efi_ssnprintf ( wchar_t *wbuf, ssize_t swsize,
 			   const char *fmt, ... );
+extern int efi_vasprintf ( wchar_t **strp, const char *fmt, va_list args );
+extern int efi_asprintf ( wchar_t **strp, const char *fmt, ... );
 
 /**
  * Write a formatted string to a wide-character buffer
diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h
index 021f6a7..daa038c 100644
--- a/src/include/ipxe/errfile.h
+++ b/src/include/ipxe/errfile.h
@@ -78,6 +78,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #define ERRFILE_dma		       ( ERRFILE_CORE | 0x00260000 )
 #define ERRFILE_cachedhcp	       ( ERRFILE_CORE | 0x00270000 )
 #define ERRFILE_acpimac		       ( ERRFILE_CORE | 0x00280000 )
+#define ERRFILE_efi_strings	       ( ERRFILE_CORE | 0x00290000 )
 
 #define ERRFILE_eisa		     ( ERRFILE_DRIVER | 0x00000000 )
 #define ERRFILE_isa		     ( ERRFILE_DRIVER | 0x00010000 )
diff --git a/src/interface/efi/efi_strings.c b/src/interface/efi/efi_strings.c
index aa3afc6..895cf42 100644
--- a/src/interface/efi/efi_strings.c
+++ b/src/interface/efi/efi_strings.c
@@ -25,6 +25,8 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #include <stddef.h>
 #include <stdarg.h>
+#include <stdlib.h>
+#include <errno.h>
 #include <ipxe/vsprintf.h>
 #include <ipxe/efi/efi_strings.h>
 
@@ -150,3 +152,45 @@ int efi_ssnprintf ( wchar_t *wbuf, ssize_t swsize, const char *fmt, ... ) {
 	va_end ( args );
 	return len;
 }
+
+/**
+ * Write a formatted string to newly allocated memory.
+ *
+ * @v wstrp		Pointer to hold allocated string
+ * @v fmt		Format string
+ * @v args		Arguments corresponding to the format string
+ * @ret	len		Length of formatted string (in wide characters)
+ */
+int efi_vasprintf ( wchar_t **wstrp, const char *fmt, va_list args ) {
+	size_t len;
+	va_list args_tmp;
+
+	/* Calculate length needed for string */
+	va_copy ( args_tmp, args );
+	len = ( efi_vsnprintf ( NULL, 0, fmt, args_tmp ) + 1 );
+	va_end ( args_tmp );
+
+	/* Allocate and fill string */
+	*wstrp = malloc ( len * sizeof ( **wstrp ) );
+	if ( ! *wstrp )
+		return -ENOMEM;
+	return efi_vsnprintf ( *wstrp, len, fmt, args );
+}
+
+/**
+ * Write a formatted string to newly allocated memory.
+ *
+ * @v wstrp		Pointer to hold allocated string
+ * @v fmt		Format string
+ * @v ...		Arguments corresponding to the format string
+ * @ret	len		Length of formatted string (in wide characters)
+ */
+int efi_asprintf ( wchar_t **wstrp, const char *fmt, ... ) {
+	va_list args;
+	int len;
+
+	va_start ( args, fmt );
+	len = efi_vasprintf ( wstrp, fmt, args );
+	va_end ( args );
+	return len;
+}