[U-Boot] [PATCH v2 2/5] lib: add some utf16 handling helpers

Rob Clark
2017-09-09T10:47:40Z

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

Signed-off-by: Rob Clark <robdclark@gmail.com>
---
include/charset.h | 65 ++++++++++++++++++++++++++++
lib/Makefile | 1 +
lib/charset.c | 101 +++++++++++++++++++++++++++++++++++++++++++
lib/efi_loader/efi_console.c | 17 ++------
4 files changed, 170 insertions(+), 14 deletions(-)
create mode 100644 include/charset.h
create mode 100644 lib/charset.c

diff --git a/include/charset.h b/include/charset.h
new file mode 100644
index 0000000000..39279f746a
--- /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 2eef1eb80e..24df11b88f 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -19,6 +19,7 @@ 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
index 0000000000..ff76e88c77
--- /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 5ebce4b544..3fc82b8726 100644
--- 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);
}

--
2.13.5