[U-Boot] [PATCH v3 4/5] efi_loader: EFI_UNICODE_COLLATION_PROTOCOL

[Heinrich Schuchardt <xypron.glpk@gmx.de>]

On 09/03/2018 11:09 PM, Alexander Graf wrote:
> 
> 
> On 03.09.18 18:35, Heinrich Schuchardt wrote:
>> The patch implements the EFI_UNICODE_COLLATION_PROTOCOL.
>>
>> Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
>> ---
>> v3:
>> 	no change
>> v2:
>> 	add more comments
>> ---
>>  MAINTAINERS                            |   2 +
>>  include/cp1250.h                       |  40 +++
>>  include/cp437.h                        |  40 +++
>>  include/efi_api.h                      |  21 ++
>>  include/efi_loader.h                   |   5 +
>>  lib/efi_loader/Makefile                |  18 +-
>>  lib/efi_loader/efi_boottime.c          |   6 +
>>  lib/efi_loader/efi_unicode_collation.c | 329 +++++++++++++++++++++++++
>>  8 files changed, 457 insertions(+), 4 deletions(-)
>>  create mode 100644 include/cp1250.h
>>  create mode 100644 include/cp437.h
>>  create mode 100644 lib/efi_loader/efi_unicode_collation.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 8c9cd83347..67b015205c 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -382,6 +382,8 @@ F:	doc/README.uefi
>>  F:	doc/README.iscsi
>>  F:	Documentation/efi.rst
>>  F:	include/capitalization.h
>> +F:	include/cp1250.h
>> +F:	include/cp437.h
>>  F:	include/efi*
>>  F:	include/pe.h
>>  F:	include/asm-generic/pe.h
>> diff --git a/include/cp1250.h b/include/cp1250.h
>> new file mode 100644
>> index 0000000000..adacf8a958
>> --- /dev/null
>> +++ b/include/cp1250.h
>> @@ -0,0 +1,40 @@
>> +/* SPDX-License-Identifier: GPL-2.0+ */
>> +
>> +/*
>> + * Constant CP1250 contains the Unicode code points for characters 0x80 - 0xff
>> + * of the code page 1250.
>> + */
>> +#define CP1250 { \
>> +	0x20ac, 0x0000, 0x201a, 0x0000, \
>> +	0x201e, 0x2026, 0x2020, 0x2021, \
>> +	0x0000, 0x2030, 0x0160, 0x2039, \
>> +	0x015a, 0x0164, 0x017d, 0x0179, \
>> +	0x0000, 0x2018, 0x2019, 0x201c, \
>> +	0x201d, 0x2022, 0x2013, 0x2014, \
>> +	0x0000, 0x2122, 0x0161, 0x203a, \
>> +	0x015b, 0x0165, 0x017e, 0x017a, \
>> +	0x00a0, 0x02c7, 0x02d8, 0x0141, \
>> +	0x00a4, 0x0104, 0x00a6, 0x00a7, \
>> +	0x00a8, 0x00a9, 0x015e, 0x00ab, \
>> +	0x00ac, 0x00ad, 0x00ae, 0x017b, \
>> +	0x00b0, 0x00b1, 0x02db, 0x0142, \
>> +	0x00b4, 0x00b5, 0x00b6, 0x00b7, \
>> +	0x00b8, 0x0105, 0x015f, 0x00bb, \
>> +	0x013d, 0x02dd, 0x013e, 0x017c, \
>> +	0x0154, 0x00c1, 0x00c2, 0x0102, \
>> +	0x00c4, 0x0139, 0x0106, 0x00c7, \
>> +	0x010c, 0x00c9, 0x0118, 0x00cb, \
>> +	0x011a, 0x00cd, 0x00ce, 0x010e, \
>> +	0x0110, 0x0143, 0x0147, 0x00d3, \
>> +	0x00d4, 0x0150, 0x00d6, 0x00d7, \
>> +	0x0158, 0x016e, 0x00da, 0x0170, \
>> +	0x00dc, 0x00dd, 0x0162, 0x00df, \
>> +	0x0155, 0x00e1, 0x00e2, 0x0103, \
>> +	0x00e4, 0x013a, 0x0107, 0x00e7, \
>> +	0x010d, 0x00e9, 0x0119, 0x00eb, \
>> +	0x011b, 0x00ed, 0x00ee, 0x010f, \
>> +	0x0111, 0x0144, 0x0148, 0x00f3, \
>> +	0x00f4, 0x0151, 0x00f6, 0x00f7, \
>> +	0x0159, 0x016f, 0x00fa, 0x0171, \
>> +	0x00fc, 0x00fd, 0x0163, 0x02d9, \
>> +}
>> diff --git a/include/cp437.h b/include/cp437.h
>> new file mode 100644
>> index 0000000000..0b2b97132e
>> --- /dev/null
>> +++ b/include/cp437.h
>> @@ -0,0 +1,40 @@
>> +/* SPDX-License-Identifier: GPL-2.0+ */
>> +
>> +/*
>> + * Constant CP437 contains the Unicode code points for characters 0x80 - 0xff
>> + * of the code page 437.
>> + */
>> +#define CP437 { \
>> +	0x00c7, 0x00fc, 0x00e9, 0x00e2, \
>> +	0x00e4, 0x00e0, 0x00e5, 0x00e7, \
>> +	0x00ea, 0x00eb, 0x00e8, 0x00ef, \
>> +	0x00ee, 0x00ec, 0x00c4, 0x00c5, \
>> +	0x00c9, 0x00e6, 0x00c6, 0x00f4, \
>> +	0x00f6, 0x00f2, 0x00fb, 0x00f9, \
>> +	0x00ff, 0x00d6, 0x00dc, 0x00a2, \
>> +	0x00a3, 0x00a5, 0x20a7, 0x0192, \
>> +	0x00e1, 0x00ed, 0x00f3, 0x00fa, \
>> +	0x00f1, 0x00d1, 0x00aa, 0x00ba, \
>> +	0x00bf, 0x2310, 0x00ac, 0x00bd, \
>> +	0x00bc, 0x00a1, 0x00ab, 0x00bb, \
>> +	0x2591, 0x2592, 0x2593, 0x2502, \
>> +	0x2524, 0x2561, 0x2562, 0x2556, \
>> +	0x2555, 0x2563, 0x2551, 0x2557, \
>> +	0x255d, 0x255c, 0x255b, 0x2510, \
>> +	0x2514, 0x2534, 0x252c, 0x251c, \
>> +	0x2500, 0x253c, 0x255e, 0x255f, \
>> +	0x255a, 0x2554, 0x2569, 0x2566, \
>> +	0x2560, 0x2550, 0x256c, 0x2567, \
>> +	0x2568, 0x2564, 0x2565, 0x2559, \
>> +	0x2558, 0x2552, 0x2553, 0x256b, \
>> +	0x256a, 0x2518, 0x250c, 0x2588, \
>> +	0x2584, 0x258c, 0x2590, 0x2580, \
>> +	0x03b1, 0x00df, 0x0393, 0x03c0, \
>> +	0x03a3, 0x03c3, 0x00b5, 0x03c4, \
>> +	0x03a6, 0x0398, 0x03a9, 0x03b4, \
>> +	0x221e, 0x03c6, 0x03b5, 0x2229, \
>> +	0x2261, 0x00b1, 0x2265, 0x2264, \
>> +	0x2320, 0x2321, 0x00f7, 0x2248, \
>> +	0x00b0, 0x2219, 0x00b7, 0x221a, \
>> +	0x207f, 0x00b2, 0x25a0, 0x00a0, \
>> +}
>> diff --git a/include/efi_api.h b/include/efi_api.h
>> index ebf2a3bc18..1efc448184 100644
>> --- a/include/efi_api.h
>> +++ b/include/efi_api.h
>> @@ -31,6 +31,7 @@ enum efi_timer_delay {
>>  	EFI_TIMER_RELATIVE = 2
>>  };
>>  
>> +#define efi_intn_t ssize_t
>>  #define efi_uintn_t size_t
>>  typedef uint16_t *efi_string_t;
>>  
>> @@ -958,4 +959,24 @@ struct efi_driver_binding_protocol {
>>  	efi_handle_t driver_binding_handle;
>>  };
>>  
>> +#define EFI_UNICODE_COLLATION_PROTOCOL2_GUID \
>> +	EFI_GUID(0xa4c751fc, 0x23ae, 0x4c3e, \
>> +		 0x92, 0xe9, 0x49, 0x64, 0xcf, 0x63, 0xf3, 0x49)
>> +struct efi_unicode_collation_protocol {
>> +	efi_intn_t (EFIAPI *stri_coll)(
>> +		struct efi_unicode_collation_protocol *this, u16 *s1, u16 *s2);
>> +	bool (EFIAPI *metai_match)(struct efi_unicode_collation_protocol *this,
>> +				   const u16 *string, const u16 *patter);
>> +	void (EFIAPI *str_lwr)(struct efi_unicode_collation_protocol
>> +			       *this, u16 *string);
>> +	void (EFIAPI *str_upr)(struct efi_unicode_collation_protocol *this,
>> +			       u16 *string);
>> +	void (EFIAPI *fat_to_str)(struct efi_unicode_collation_protocol *this,
>> +				  efi_uintn_t fat_size, char *fat, u16 *string);
>> +	bool (EFIAPI *str_to_fat)(struct efi_unicode_collation_protocol *this,
>> +				  const u16 *string, efi_uintn_t fat_size,
>> +				  char *fat);
>> +	char *supported_languages;
>> +};
>> +
>>  #endif
>> diff --git a/include/efi_loader.h b/include/efi_loader.h
>> index b46babf931..736e82c506 100644
>> --- a/include/efi_loader.h
>> +++ b/include/efi_loader.h
>> @@ -98,6 +98,9 @@ extern const struct efi_device_path_to_text_protocol efi_device_path_to_text;
>>  /* implementation of the EFI_DEVICE_PATH_UTILITIES_PROTOCOL */
>>  extern const struct efi_device_path_utilities_protocol
>>  					efi_device_path_utilities;
>> +/* Implementation of the EFI_UNICODE_COLLATION_PROTOCOL */
>> +extern const struct efi_unicode_collation_protocol
>> +					efi_unicode_collation_protocol;
>>  
>>  uint16_t *efi_dp_str(struct efi_device_path *dp);
>>  
>> @@ -127,6 +130,8 @@ extern const efi_guid_t efi_file_info_guid;
>>  /* GUID for file system information */
>>  extern const efi_guid_t efi_file_system_info_guid;
>>  extern const efi_guid_t efi_guid_device_path_utilities_protocol;
>> +/* GUID of the Unicode collation protocol */
>> +extern const efi_guid_t efi_guid_unicode_collation_protocol;
>>  
>>  extern unsigned int __efi_runtime_start, __efi_runtime_stop;
>>  extern unsigned int __efi_runtime_rel_start, __efi_runtime_rel_stop;
>> diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
>> index 1ffbf52a89..0769df20f7 100644
>> --- a/lib/efi_loader/Makefile
>> +++ b/lib/efi_loader/Makefile
>> @@ -17,10 +17,20 @@ always += helloworld.efi
>>  endif
>>  
>>  obj-$(CONFIG_CMD_BOOTEFI_HELLO) += helloworld_efi.o
>> -obj-y += efi_image_loader.o efi_boottime.o efi_runtime.o efi_console.o
>> -obj-y += efi_memory.o efi_device_path_to_text.o efi_device_path.o
>> -obj-y += efi_device_path_utilities.o efi_file.o efi_variable.o efi_bootmgr.o
>> -obj-y += efi_watchdog.o
>> +obj-y += \
>> +efi_bootmgr.o \
>> +efi_boottime.o \
>> +efi_console.o \
>> +efi_device_path.o \
>> +efi_device_path_to_text.o \
>> +efi_device_path_utilities.o \
>> +efi_file.o \
>> +efi_image_loader.o \
>> +efi_memory.o \
>> +efi_runtime.o \
>> +efi_unicode_collation.o \
>> +efi_variable.o \
>> +efi_watchdog.o
> 
> Instead of line breaking them, just make each line an obj-y += line.
> 
>>  obj-$(CONFIG_LCD) += efi_gop.o
>>  obj-$(CONFIG_DM_VIDEO) += efi_gop.o
>>  obj-$(CONFIG_PARTITIONS) += efi_disk.o
>> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
>> index cd5fdb7aa8..f9f59b93f9 100644
>> --- a/lib/efi_loader/efi_boottime.c
>> +++ b/lib/efi_loader/efi_boottime.c
>> @@ -1527,6 +1527,12 @@ efi_status_t efi_setup_loaded_image(
>>  	if (ret != EFI_SUCCESS)
>>  		goto failure;
>>  
>> +	ret = efi_add_protocol(obj->handle,
>> +			       &efi_guid_unicode_collation_protocol,
>> +			       (void *)&efi_unicode_collation_protocol);
>> +	if (ret != EFI_SUCCESS)
>> +		goto failure;
>> +
>>  	return ret;
>>  failure:
>>  	printf("ERROR: Failure to install protocols for loaded image\n");
>> diff --git a/lib/efi_loader/efi_unicode_collation.c b/lib/efi_loader/efi_unicode_collation.c
>> new file mode 100644
>> index 0000000000..2c1e819174
>> --- /dev/null
>> +++ b/lib/efi_loader/efi_unicode_collation.c
>> @@ -0,0 +1,329 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * EFI Unicode collation protocol
>> + *
>> + * Copyright (c) 2018 Heinrich Schuchardt <xypron.glpk@gmx.de>
>> + */
>> +
>> +#include <common.h>
>> +#include <charset.h>
>> +#include <cp1250.h>
>> +#include <cp437.h>
>> +#include <efi_loader.h>
>> +
>> +/* Characters that may not be used in file names */
>> +static const char illegal[] = "<>:\"/\\|?*";
>> +
>> +/*
>> + * EDK2 assumes codepage 1250 when creating FAT 8.3 file names.
>> + * Linux defaults to codepage 437 for FAT 8.3 file names.
>> + */
>> +#if CONFIG_FAT_DEFAULT_CODEPAGE == 1250
>> +/* Unicode code points for code page 1250 characters 0x80 - 0xff */
>> +static const u16 codepage[] = CP1250;
>> +#else
>> +/* Unicode code points for code page 437 characters 0x80 - 0xff */
>> +static const u16 codepage[] = CP437;
>> +#endif
>> +
>> +/* GUID of the EFI_UNICODE_COLLATION_PROTOCOL */
>> +const efi_guid_t efi_guid_unicode_collation_protocol =
>> +	EFI_UNICODE_COLLATION_PROTOCOL2_GUID;
>> +
>> +/**
>> + * efi_stri_coll() - compare utf-16 strings case-insenitively
>> + *
>> + * @this:	unicode collation protocol instance
>> + * @s1:		first string
>> + * @s2:		second string
>> + *
>> + * This function implements the StriColl() service of the
>> + * EFI_UNICODE_COLLATION_PROTOCOL.
>> + *
>> + * See the Unified Extensible Firmware Interface (UEFI) specification for
>> + * details.
>> + *
>> + * TODO:
>> + * The implementation does not follow the Unicode collation algorithm.
>> + * For ASCII characters it results in the same sort order as EDK2.
>> + * We could use table UNICODE_CAPITALIZATION_TABLE for better results.
>> + *
>> + * Return:	0: s1 == s2, > 0: s1 > s2, < 0: s1 < s2
>> + */
>> +static efi_intn_t EFIAPI efi_stri_coll(
>> +		struct efi_unicode_collation_protocol *this, u16 *s1, u16 *s2)
>> +{
>> +	s32 c1, c2;
>> +	efi_intn_t ret = 0;
>> +
>> +	EFI_ENTRY("%p, %ls, %ls", this, s1, s2);
>> +	for (; *s1 | *s2; ++s1, ++s2) {
>> +		c1 = utf_to_upper(*s1);
>> +		c2 = utf_to_upper(*s2);
>> +		if (c1 < c2) {
>> +			ret = -1;
>> +			goto out;
>> +		} else if (c1 > c2) {
>> +			ret = 1;
>> +			goto out;
>> +		}
>> +	}
>> +out:
>> +	EFI_EXIT(EFI_SUCCESS);
>> +	return ret;
>> +}
>> +
>> +/**
>> + * metai_match() - compare utf-16 string with a pattern string case-insenitively
>> + *
>> + * @s:		string to compare
>> + * @p:		pattern string
>> + *
>> + * The pattern string may use these:
>> + *	- * matches >= 0 characters
>> + *	- ? matches 1 character
>> + *	- [<char1><char2>...<charN>] match any character in the set
>> + *	- [<char1>-<char2>] matches any character in the range
>> + *
>> + * This function is called my efi_metai_match().
>> + *
>> + * For '*' pattern searches this function calls itself recursively.
>> + * Performance-wise this is suboptimal, especially for multiple '*' wildcards.
>> + * But it results in simple code.
>> + *
>> + * Return:	true if the string is matched.
>> + */
>> +static bool metai_match(const u16 *s, const u16 *p)
>> +{
>> +	u16 first;
>> +
>> +	for (; *s && *p; ++s, ++p) {
>> +		switch (*p) {
>> +		case '*':
>> +			/* Match 0 or more characters */
>> +			++p;
>> +			for (;; ++s) {
>> +				if (metai_match(s, p))
>> +					return true;
>> +				if (!*s)
>> +					return false;
>> +			}
>> +		case '?':
>> +			/* Match any one character */
>> +			break;
>> +		case '[':
>> +			/* Match any character in the set */
>> +			++p;
>> +			first = *p;
>> +			if (first == ']')
>> +				/* Empty set */
>> +				return false;
>> +			++p;
>> +			if (*p == '-') {
>> +				/* Range */
>> +				++p;
>> +				if (*s < first || *s > *p)
>> +					return false;
>> +				++p;
>> +				if (*p != ']')
>> +					return false;
>> +			} else {
>> +				/* Set */
>> +				bool hit = false;
>> +
>> +				if (*s == first)
>> +					hit = true;
>> +				for (; *p && *p != ']'; ++p) {
>> +					if (*p == *s)
>> +						hit = true;
>> +				}
>> +				if (!hit || *p != ']')
>> +					return false;
>> +			}
>> +			break;
>> +		default:
>> +			/* Match one character */
>> +			if (*p != *s)
>> +				return false;
>> +		}
>> +	}
>> +	if (!*p && !*s)
>> +		return true;
>> +	return false;
>> +}
>> +
>> +/**
>> + * efi_metai_match() - compare utf-16 string with a pattern string
>> + *		       case-insenitively
>> + *
>> + * @this:	unicode collation protocol instance
>> + * @s:		string to compare
>> + * @p:		pattern string
>> + *
>> + * The pattern string may use these:
>> + *	- * matches >= 0 characters
>> + *	- ? matches 1 character
>> + *	- [<char1><char2>...<charN>] match any character in the set
>> + *	- [<char1>-<char2>] matches any character in the range
>> + *
>> + * This function implements the MetaMatch() service of the
>> + * EFI_UNICODE_COLLATION_PROTOCOL.
>> + *
>> + * Return:	true if the string is matched.
>> + */
>> +static bool EFIAPI efi_metai_match(struct efi_unicode_collation_protocol *this,
>> +				   const u16 *string, const u16 *pattern)
>> +{
>> +	bool ret;
>> +
>> +	EFI_ENTRY("%p, %ls, %ls", this, string, pattern);
>> +	ret =  metai_match(string, pattern);
>> +	EFI_EXIT(EFI_SUCCESS);
>> +	return ret;
>> +}
>> +
>> +/**
>> + * efi_str_lwr() - convert to lower case
>> + *
>> + * @this:	unicode collation protocol instance
>> + * @string:	string to convert
>> + * @p:		pattern string
>> + *
>> + * The conversion is done in place. As long as upper and lower letters use the
>> + * same number of words this does not pose a problem.
>> + *
>> + * This function implements the StrLwr() service of the
>> + * EFI_UNICODE_COLLATION_PROTOCOL.
>> + */
>> +static void EFIAPI efi_str_lwr(struct efi_unicode_collation_protocol *this,
>> +			       u16 *string)
>> +{
>> +	EFI_ENTRY("%p, %ls", this, string);
>> +	for (; *string; ++string)
>> +		*string = utf_to_lower(*string);
>> +	EFI_EXIT(EFI_SUCCESS);
>> +}
>> +
>> +/**
>> + * efi_str_upr() - convert to upper case
>> + *
>> + * @this:	unicode collation protocol instance
>> + * @string:	string to convert
>> + * @p:		pattern string
>> + *
>> + * The conversion is done in place. As long as upper and lower letters use the
>> + * same number of words this does not pose a problem.
>> + *
>> + * This function implements the StrUpr() service of the
>> + * EFI_UNICODE_COLLATION_PROTOCOL.
>> + */
>> +static void EFIAPI efi_str_upr(struct efi_unicode_collation_protocol *this,
>> +			       u16 *string)
>> +{
>> +	EFI_ENTRY("%p, %ls", this, string);
>> +	for (; *string; ++string)
>> +		*string = utf_to_upper(*string);
>> +	EFI_EXIT(EFI_SUCCESS);
>> +}
>> +
>> +/**
>> + * efi_fat_to_str() - convert an 8.3 file name from an OEM codepage to Unicode
>> + *
>> + * @this:	unicode collation protocol instance
>> + * @fat_size:	size of the string to convert
>> + * @fat:	string to convert
>> + * @string:	converted string
>> + *
>> + * This function implements the FatToStr() service of the
>> + * EFI_UNICODE_COLLATION_PROTOCOL.
>> + */
>> +static void EFIAPI efi_fat_to_str(struct efi_unicode_collation_protocol *this,
>> +				  efi_uintn_t fat_size, char *fat, u16 *string)
>> +{
>> +	efi_uintn_t i;
>> +	u16 c;
>> +
>> +	EFI_ENTRY("%p, %zu, %s, %p", this, fat_size, fat, string);
>> +	for (i = 0; i < fat_size; ++i) {
>> +		c = (unsigned char)fat[i];
>> +		if (c > 0x80)
>> +			c = codepage[i - 0x80];
>> +		string[i] = c;
>> +		if (!c)
>> +			break;
>> +	}
>> +	string[i] = 0;
>> +	EFI_EXIT(EFI_SUCCESS);
>> +}
>> +
>> +/**
>> + * efi_fat_to_str() - convert a utf-16 string to legal characters for a FAT
>> + *                    file name in an OEM code page
>> + *
>> + * @this:	unicode collation protocol instance
>> + * @string:	Unicode string to convert
>> + * @fat_size:	size of the target buffer
>> + * @fat:	converted string
>> + *
>> + * This function implements the StrToFat() service of the
>> + * EFI_UNICODE_COLLATION_PROTOCOL.
>> + *
>> + * Return:	true if an illegal character was substituted by '_'.
>> + */
>> +static bool EFIAPI efi_str_to_fat(struct efi_unicode_collation_protocol *this,
>> +				  const u16 *string, efi_uintn_t fat_size,
>> +				  char *fat)
>> +{
>> +	efi_uintn_t i;
>> +	s32 c;
>> +	bool ret = false;
>> +
>> +	EFI_ENTRY("%p, %ls, %zu, %p", this, string, fat_size, fat);
>> +	for (i = 0; i < fat_size;) {
>> +		c = utf16_get(&string);
>> +		switch (c) {
>> +		/* Ignore period and space */
>> +		case '.':
>> +		case ' ':
>> +			continue;
>> +		case 0:
>> +			break;
>> +		}
>> +		c = utf_to_upper(c);
>> +		if (c >= 0x80) {
>> +			int j;
>> +
>> +			/* Look for codepage translation */
>> +			for (j = 0; j < 0x80; ++j) {
>> +				if (c == codepage[j]) {
>> +					c = j + 0x80;
>> +					break;
>> +				}
>> +			}
>> +			if (j >= 0x80) {
>> +				c = '_';
>> +				ret = true;
>> +			}
>> +		} else if (c && (c < 0x20 || strchr(illegal, c))) {
>> +			c = '_';
>> +			ret = true;
>> +		}
>> +
>> +		fat[i] = c;
>> +		if (!c)
>> +			break;
>> +		++i;
>> +	}
>> +	EFI_EXIT(EFI_SUCCESS);
>> +	return ret;
>> +}
>> +
>> +const struct efi_unicode_collation_protocol efi_unicode_collation_protocol = {
>> +	.stri_coll = efi_stri_coll,
>> +	.metai_match = efi_metai_match,
>> +	.str_lwr = efi_str_lwr,
>> +	.str_upr = efi_str_upr,
>> +	.fat_to_str = efi_fat_to_str,
>> +	.str_to_fat = efi_str_to_fat,
>> +	.supported_languages = "en-US",
> 
> I have to admit I'm slightly puzzled on the supported language field.
> The spec says quite clearly in appendix M what to do, but everyone seems
> to interpret the specs differently:
> 
>   edk2 provides "en"
>   appendix M example is "en-us"
>   your patch provides "en-US"
> 
> I'm not sure which one of them is correct :).
> 

The spec refers to RFC 4646. RFC 4646 refers to ISO 3166 which uses
capital letters for the two letter region codes.

In RFC 4646 you can find the following example:

en-US (English as used in the United States)

The value from edk2 complies with RFC 4646. It simply does not specify a
region.

So should I change the value to match edk2?

Best regards

Heinrich

> 
> Alex
>