[PATCH v2] MdePkg: Support FDT library.

["Benny Lin" <benny.lin@intel.com>]

From: Benny Lin <benny.lin@intel.com>

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4392
Add FDT support in EDK2 by submodule 3rd party libfdt
(https://github.com/devicetree-org/pylibfdt/tree/main/libfdt)
1. Correct the typo.
2. Remove no use definitions from LibFdtSupport.h.
3. Refer to LibcLib implementation by Pedro.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Cc: Chasel Chiu <chasel.chiu@intel.com>
Cc: James Lu <james.lu@intel.com>
Cc: Gua Guo <gua.guo@intel.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Signed-off-by: Benny Lin <benny.lin@intel.com>
---
 MdePkg/Include/Library/FdtLib.h           |   2 +-
 MdePkg/Library/BaseFdtLib/FdtLib.c        |   2 +-
 MdePkg/Library/BaseFdtLib/LibFdtSupport.h |   6 +-
 MdePkg/Library/BaseFdtLib/LibFdtWrapper.c | 215 +++++++++++---------
 4 files changed, 125 insertions(+), 100 deletions(-)

diff --git a/MdePkg/Include/Library/FdtLib.h b/MdePkg/Include/Library/FdtLib.h
index bcb097b77e..d1e67c773f 100644
--- a/MdePkg/Include/Library/FdtLib.h
+++ b/MdePkg/Include/Library/FdtLib.h
@@ -276,7 +276,7 @@ FdtAddSubnode (
   );
 
 /**
-  Add or modify a porperty in the given node.
+  Add or modify a property in the given node.
 
   @param[in] Fdt            The pointer to FDT blob.
   @param[in] NodeOffset     The offset to the node offset which want to add in.
diff --git a/MdePkg/Library/BaseFdtLib/FdtLib.c b/MdePkg/Library/BaseFdtLib/FdtLib.c
index ba9a284e58..877c832c50 100644
--- a/MdePkg/Library/BaseFdtLib/FdtLib.c
+++ b/MdePkg/Library/BaseFdtLib/FdtLib.c
@@ -259,7 +259,7 @@ FdtAddSubnode (
 }
 
 /**
-  Add or modify a porperty in the given node.
+  Add or modify a property in the given node.
 
   @param[in] Fdt            The pointer to FDT blob.
   @param[in] NodeOffset     The offset to the node offset which want to add in.
diff --git a/MdePkg/Library/BaseFdtLib/LibFdtSupport.h b/MdePkg/Library/BaseFdtLib/LibFdtSupport.h
index 58b0bb403e..92d7bf0946 100644
--- a/MdePkg/Library/BaseFdtLib/LibFdtSupport.h
+++ b/MdePkg/Library/BaseFdtLib/LibFdtSupport.h
@@ -29,12 +29,10 @@ typedef BOOLEAN  bool;
 //
 // Definitions for global constants used by libfdt library routines
 //
-#ifndef INT_MAX
-#define INT_MAX  0x7FFFFFFF              /* Maximum (signed) int value */
-#endif
+#define INT_MAX          0x7FFFFFFF      /* Maximum (signed) int value */
 #define INT32_MAX        0x7FFFFFFF      /* Maximum (signed) int32 value */
 #define UINT32_MAX       0xFFFFFFFF      /* Maximum unsigned int32 value */
-#define MAX_STRING_SIZE  0x1000
+#define ULONG_MAX        0xFFFFFFFF      /* Maximum unsigned long value */
 
 //
 // Function prototypes of libfdt Library routines
diff --git a/MdePkg/Library/BaseFdtLib/LibFdtWrapper.c b/MdePkg/Library/BaseFdtLib/LibFdtWrapper.c
index 3f1cc69dc6..50b533a2b0 100644
--- a/MdePkg/Library/BaseFdtLib/LibFdtWrapper.c
+++ b/MdePkg/Library/BaseFdtLib/LibFdtWrapper.c
@@ -8,131 +8,158 @@
 **/
 
 #include "LibFdtSupport.h"
-#include <Library/DebugLib.h>
 
-/**
-  Returns the first occurrence of a Null-terminated ASCII character
-  in a Null-terminated ASCII string.
+char *
+strchr (
+  const char  *Str,
+  int         Char
+  )
+{
+  char  *S;
 
-  This function scans the contents of the ASCII string specified by s
-  and returns the first occurrence of c. If c is not found in s,
-  then NULL is returned. If the length of c is zero, then s is returned.
+  S = (char *)Str;
 
-  @param  s               The pointer to a Null-terminated ASCII string.
-  @param  c               The pointer to a Null-terminated ASCII character to search for.
+  for ( ; ; S++) {
+    if (*S == Char) {
+      return S;
+    }
 
-  @retval NULL            If the c does not appear in s.
-  @retval others          If there is a match return the first occurrence of c.
-                          If the length of c is zero,return s.
+    if (*S == '\0') {
+      return NULL;
+    }
+  }
+}
 
-**/
 char *
-strchr (
-  const char  *s,
-  int         c
+strrchr (
+  const char  *Str,
+  int         Char
   )
 {
-  char  pattern[2];
+  char  *S, *last;
 
-  pattern[0] = (CHAR8)c;
-  pattern[1] = 0;
-  return AsciiStrStr (s, pattern);
-}
+  S    = (char *)Str;
+  last = NULL;
 
-/**
-  Returns the last occurrence of a Null-terminated ASCII character
-  in a Null-terminated ASCII string.
-
-  This function scans the contents of the ASCII string specified by s
-  and returns the last occurrence of c. If c is not found in s,
-  then NULL is returned. If the length of c is zero, then s is returned.
+  for ( ; ; S++) {
+    if (*S == Char) {
+      last = S;
+    }
 
-  @param  s               The pointer to a Null-terminated ASCII string.
-  @param  c               The pointer to a Null-terminated ASCII character to search for.
+    if (*S == '\0') {
+      return last;
+    }
+  }
+}
 
-  @retval NULL            If the c does not appear in s.
-  @retval others          If there is a match return the last occurrence of c.
-                          If the length of c is zero,return s.
+STATIC
+int
+__isspace (
+  int  ch
+  )
+{
+  // basic ASCII ctype.h:isspace(). Not efficient
+  return ch == '\r' || ch == '\n' || ch == ' ' || ch == '\t' || ch == '\v' || ch == '\f';
+}
 
-**/
-char *
-strrchr (
-  const char  *s,
-  int         c
+unsigned long
+strtoul (
+  const char  *Nptr,
+  char        **EndPtr,
+  int         Base
   )
 {
-  char         pattern[2];
-  CONST CHAR8  *LastMatch;
-  CONST CHAR8  *StringTmp;
-  CONST CHAR8  *SearchString;
-
-  pattern[0]   = (CHAR8)c;
-  pattern[1]   = 0;
-  SearchString = pattern;
-
-  //
-  // Return NULL if both strings are less long than PcdMaximumAsciiStringLength
-  //
-  if ((AsciiStrSize (s) == 0) || (AsciiStrSize (SearchString) == 0)) {
-    return NULL;
+  BOOLEAN        Negate;
+  BOOLEAN        Overflow;
+  unsigned long  Val;
+
+  Negate   = FALSE;
+  Overflow = FALSE;
+  Val      = 0;
+
+  // Reject bad numeric bases
+  if ((Base < 0) || (Base == 1) || (Base > 36)) {
+    return 0;
   }
 
-  if (*SearchString == '\0') {
-    return (CHAR8 *)s;
+  // Skip whitespace
+  while (__isspace (*Nptr)) {
+    Nptr++;
   }
 
-  LastMatch = NULL;
-  do {
-    StringTmp = AsciiStrStr (s, SearchString);
+  // Check for + or - prefixes
+  if (*Nptr == '-') {
+    Negate = TRUE;
+    Nptr++;
+  } else if (*Nptr == '+') {
+    Nptr++;
+  }
 
-    if (StringTmp == NULL) {
-      break;
+  // Consume the start, autodetecting base if needed
+  if ((Nptr[0] == '0') && ((Nptr[1] == 'x') || (Nptr[1] == 'X')) && ((Base == 0) || (Base == 16))) {
+    // Hex
+    Nptr += 2;
+    Base  = 16;
+  } else if ((Nptr[0] == '0') && ((Nptr[1] == 'b') || (Nptr[1] == 'B')) && ((Base == 0) || (Base == 2))) {
+    // Binary (standard pending C23)
+    Nptr += 2;
+    Base  = 2;
+  } else if ((Nptr[0] == '0') && ((Base == 0) || (Base == 8))) {
+    // Octal
+    Nptr++;
+    Base = 8;
+  } else {
+    if (Base == 0) {
+      // Assume decimal
+      Base = 10;
     }
+  }
 
-    LastMatch = StringTmp;
-    s         = StringTmp + 1;
-  } while (s != NULL);
+  while (TRUE) {
+    int            Digit;
+    char           C;
+    unsigned long  NewVal;
 
-  return (CHAR8 *)LastMatch;
-}
+    C     = *Nptr;
+    Digit = -1;
+
+    if ((C >= '0') && (C <= '9')) {
+      Digit = C - '0';
+    } else if ((C >= 'a') && (C <= 'z')) {
+      Digit = C - 'a' + 10;
+    } else if ((C >= 'A') && (C <= 'Z')) {
+      Digit = C - 'A' + 10;
+    }
 
-/**
-  Convert a Null-terminated Ascii decimal or hexadecimal string to a value of type UINTN.
+    if ((Digit == -1) || (Digit >= Base)) {
+      // Note that this case also handles the \0
+      if (EndPtr) {
+        *EndPtr = (char *)Nptr;
+      }
 
-  This function outputs a value of type UINTN by interpreting the contents of
-  the Ascii string specified by String as a decimal or hexadecimal number.
+      break;
+    }
 
-  @param  nptr                     Pointer to a Null-terminated Ascii string.
-  @param  endptr                   Pointer to character that stops scan.
-  @param  base                     Pointer to decimal or hexadecimal.
+    NewVal = Val * Base + Digit;
 
-  @retval MAX_UINTN                If nptr is NULL.
-                                   If endptr is NULL.
-                                   If base is not 10 or 16.
-  @retval others                   Value is translated from String.
+    if (NewVal < Val) {
+      // Overflow
+      Overflow = TRUE;
+    }
 
-**/
-unsigned long
-strtoul (
-  const char  *nptr,
-  char        **endptr,
-  int         base
-  )
-{
-  RETURN_STATUS  Status;
-  UINTN          ReturnValue;
+    Val = NewVal;
 
-  if (base == 10) {
-    Status = AsciiStrDecimalToUintnS (nptr, endptr, &ReturnValue);
-  } else if (base == 16) {
-    Status = AsciiStrHexToUintnS (nptr, endptr, &ReturnValue);
-  } else {
-    Status = RETURN_INVALID_PARAMETER;
+    Nptr++;
+  }
+
+  if (Negate) {
+    Val = -Val;
   }
 
-  if (RETURN_ERROR (Status)) {
-    return MAX_UINTN;
+  if (Overflow) {
+    Val = ULONG_MAX;
   }
 
-  return (unsigned long)ReturnValue;
+  // TODO: We're lacking errno here.
+  return Val;
 }
-- 
2.39.1.windows.1