Eric Lee / smarc-uboot

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lib/charset.c 3.07 KB
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78178bb0c   Rob Clark   lib: add some utf... 
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  /*
   *  charset conversion utils
   *
   *  Copyright (c) 2017 Rob Clark
   *
   *  SPDX-License-Identifier:     GPL-2.0+
   */
78178bb0c   Rob Clark   lib: add some utf... 
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  #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;
  }
f58c5ecb8   Heinrich Schuchardt   efi_loader: new f... 
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  uint16_t *utf8_to_utf16(uint16_t *dest, const uint8_t *src, size_t size)
  {
  	while (size--) {
  		int extension_bytes;
  		uint32_t code;
  
  		extension_bytes = 0;
  		if (*src <= 0x7f) {
  			code = *src++;
  			/* Exit on zero byte */
  			if (!code)
  				size = 0;
  		} else if (*src <= 0xbf) {
  			/* Illegal code */
  			code = '?';
  		} else if (*src <= 0xdf) {
  			code = *src++ & 0x1f;
  			extension_bytes = 1;
  		} else if (*src <= 0xef) {
  			code = *src++ & 0x0f;
  			extension_bytes = 2;
  		} else if (*src <= 0xf7) {
  			code = *src++ & 0x07;
  			extension_bytes = 3;
  		} else {
  			/* Illegal code */
  			code = '?';
  		}
  
  		for (; extension_bytes && size; --size, --extension_bytes) {
  			if ((*src & 0xc0) == 0x80) {
  				code <<= 6;
  				code |= *src++ & 0x3f;
  			} else {
  				/* Illegal code */
  				code = '?';
  				++src;
  				--size;
  				break;
  			}
  		}
  
  		if (code < 0x10000) {
  			*dest++ = code;
  		} else {
  			/*
  			 * Simplified expression for
  			 * (((code - 0x10000) >> 10) & 0x3ff) | 0xd800
  			 */
  			*dest++ = (code >> 10) + 0xd7c0;
  			*dest++ = (code & 0x3ff) | 0xdc00;
  		}
  	}
  	return dest;
  }