lib: add some utf16 handling helpers

We'll eventually want these in a few places in efi_loader, and also
vsprintf.

Signed-off-by: Rob Clark <robdclark@gmail.com>

diff --git a/include/charset.h b/include/charset.h
new file mode 100644 (file)
index 0000000..39279f7
--- /dev/null
+++ b/include/charset.h
@@ -0,0 +1,65 @@
+/*
+ *  charset conversion utils
+ *
+ *  Copyright (c) 2017 Rob Clark
+ *
+ *  SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#ifndef __CHARSET_H_
+#define __CHARSET_H_
+
+#define MAX_UTF8_PER_UTF16 4
+
+/**
+ * utf16_strlen() - Get the length of an utf16 string
+ *
+ * Returns the number of 16 bit characters in an utf16 string, not
+ * including the terminating NULL character.
+ *
+ * @in     the string to measure
+ * @return the string length
+ */
+size_t utf16_strlen(const uint16_t *in);
+
+/**
+ * utf16_strnlen() - Get the length of a fixed-size utf16 string.
+ *
+ * Returns the number of 16 bit characters in an utf16 string,
+ * not including the terminating NULL character, but at most
+ * 'count' number of characters.  In doing this, utf16_strnlen()
+ * looks at only the first 'count' characters.
+ *
+ * @in     the string to measure
+ * @count  the maximum number of characters to count
+ * @return the string length, up to a maximum of 'count'
+ */
+size_t utf16_strnlen(const uint16_t *in, size_t count);
+
+/**
+ * utf16_strcpy() - UTF16 equivalent of strcpy()
+ */
+uint16_t *utf16_strcpy(uint16_t *dest, const uint16_t *src);
+
+/**
+ * utf16_strdup() - UTF16 equivalent of strdup()
+ */
+uint16_t *utf16_strdup(const uint16_t *s);
+
+/**
+ * utf16_to_utf8() - Convert an utf16 string to utf8
+ *
+ * Converts 'size' characters of the utf16 string 'src' to utf8
+ * written to the 'dest' buffer.
+ *
+ * NOTE that a single utf16 character can generate up to 4 utf8
+ * characters.  See MAX_UTF8_PER_UTF16.
+ *
+ * @dest   the destination buffer to write the utf8 characters
+ * @src    the source utf16 string
+ * @size   the number of utf16 characters to convert
+ * @return the pointer to the first unwritten byte in 'dest'
+ */
+uint8_t *utf16_to_utf8(uint8_t *dest, const uint16_t *src, size_t size);
+
+#endif /* __CHARSET_H_ */

diff --git a/lib/Makefile b/lib/Makefile
index da6a11aca335a8356418dc7f26ca1ceed241ad55..15bba9eac24a5579721ff37226b3b948cac0ea33 100644 (file)
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_OF_LIVE) += of_live.o
 obj-$(CONFIG_CMD_DHRYSTONE) += dhry/
 
 obj-$(CONFIG_AES) += aes.o
+obj-y += charset.o
 obj-$(CONFIG_USB_TTY) += circbuf.o
 obj-y += crc7.o
 obj-y += crc8.o

diff --git a/lib/charset.c b/lib/charset.c
new file mode 100644 (file)
index 0000000..ff76e88
--- /dev/null
+++ b/lib/charset.c
@@ -0,0 +1,101 @@
+/*
+ *  charset conversion utils
+ *
+ *  Copyright (c) 2017 Rob Clark
+ *
+ *  SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <charset.h>
+#include <malloc.h>
+
+/*
+ * utf8/utf16 conversion mostly lifted from grub
+ */
+
+size_t utf16_strlen(const uint16_t *in)
+{
+       size_t i;
+       for (i = 0; in[i]; i++);
+       return i;
+}
+
+size_t utf16_strnlen(const uint16_t *in, size_t count)
+{
+       size_t i;
+       for (i = 0; count-- && in[i]; i++);
+       return i;
+}
+
+uint16_t *utf16_strcpy(uint16_t *dest, const uint16_t *src)
+{
+       uint16_t *tmp = dest;
+
+       while ((*dest++ = *src++) != '\0')
+               /* nothing */;
+       return tmp;
+
+}
+
+uint16_t *utf16_strdup(const uint16_t *s)
+{
+       uint16_t *new;
+       if (!s || !(new = malloc((utf16_strlen(s) + 1) * 2)))
+               return NULL;
+       utf16_strcpy(new, s);
+       return new;
+}
+
+/* Convert UTF-16 to UTF-8.  */
+uint8_t *utf16_to_utf8(uint8_t *dest, const uint16_t *src, size_t size)
+{
+       uint32_t code_high = 0;
+
+       while (size--) {
+               uint32_t code = *src++;
+
+               if (code_high) {
+                       if (code >= 0xDC00 && code <= 0xDFFF) {
+                               /* Surrogate pair.  */
+                               code = ((code_high - 0xD800) << 10) + (code - 0xDC00) + 0x10000;
+
+                               *dest++ = (code >> 18) | 0xF0;
+                               *dest++ = ((code >> 12) & 0x3F) | 0x80;
+                               *dest++ = ((code >> 6) & 0x3F) | 0x80;
+                               *dest++ = (code & 0x3F) | 0x80;
+                       } else {
+                               /* Error...  */
+                               *dest++ = '?';
+                               /* *src may be valid. Don't eat it.  */
+                               src--;
+                       }
+
+                       code_high = 0;
+               } else {
+                       if (code <= 0x007F) {
+                               *dest++ = code;
+                       } else if (code <= 0x07FF) {
+                               *dest++ = (code >> 6) | 0xC0;
+                               *dest++ = (code & 0x3F) | 0x80;
+                       } else if (code >= 0xD800 && code <= 0xDBFF) {
+                               code_high = code;
+                               continue;
+                       } else if (code >= 0xDC00 && code <= 0xDFFF) {
+                               /* Error... */
+                               *dest++ = '?';
+                       } else if (code < 0x10000) {
+                               *dest++ = (code >> 12) | 0xE0;
+                               *dest++ = ((code >> 6) & 0x3F) | 0x80;
+                               *dest++ = (code & 0x3F) | 0x80;
+                       } else {
+                               *dest++ = (code >> 18) | 0xF0;
+                               *dest++ = ((code >> 12) & 0x3F) | 0x80;
+                               *dest++ = ((code >> 6) & 0x3F) | 0x80;
+                               *dest++ = (code & 0x3F) | 0x80;
+                       }
+               }
+       }
+
+       return dest;
+}

diff --git a/lib/efi_loader/efi_console.c b/lib/efi_loader/efi_console.c
index 5ebce4b544daf4a20ec996bb240830ece3e1ed8d..3fc82b87261cba504da576393fb589d769b6eaa1 100644 (file)
--- a/lib/efi_loader/efi_console.c
+++ b/lib/efi_loader/efi_console.c
@@ -7,6 +7,7 @@
  */
 
 #include <common.h>
+#include <charset.h>
 #include <efi_loader.h>
 
 static bool console_size_queried;
@@ -138,20 +139,8 @@ static efi_status_t EFIAPI efi_cout_reset(
 
 static void print_unicode_in_utf8(u16 c)
 {
-       char utf8[4] = { 0 };
-       char *b = utf8;
-
-       if (c < 0x80) {
-               *(b++) = c;
-       } else if (c < 0x800) {
-               *(b++) = 192 + c / 64;
-               *(b++) = 128 + c % 64;
-       } else {
-               *(b++) = 224 + c / 4096;
-               *(b++) = 128 + c / 64 % 64;
-               *(b++) = 128 + c % 64;
-       }
-
+       char utf8[MAX_UTF8_PER_UTF16] = { 0 };
+       utf16_to_utf8((u8 *)utf8, &c, 1);
        puts(utf8);
 }