Automatic +Translation of Header Files From C++

Some header files that the bootstrap uses are shared with the Kernel and +are written in C++. The header files are shared to avoid duplicate definitions +of, for example, super page layout in the kernel and in the bootstrap. Since +the bootstrap is written in assembler, the C++ header files must be translated +to assembler-syntax include files.

This is done automatically under the control of the generic makefile. The +translation tool can produce include files in ARMASM, GNU AS or Turbo Assembler +(for X86) syntax; the examples will all be in ARMASM syntax.

It should be noted that the translation tool does not process #include directives +or any other preprocessor directives. Only the types listed below and types +created from those (by typedef or class/struct declaration) will be recognised.

The following elements of C++ header files are translated:

Compile time constants, both at file and class scope

Constants +at file scope have the same name in the assembler include file and constants +at class scope have the name <class name>_<constant name> in +the assembler include file. Initialiser values may be expressions and may +involve previously-defined constants or enumerators as well as sizeof operations +applied to previously-defined types.

For example:

const TInt KBufferSize = 1024; +class X { const TInt KClassConstant = 100; }; +

translates to:

KBufferSize EQU 0x00000400 +X_KClassConstant EQU 0x00000064 +

Enumerators, both at file and class scope

For example:

enum T1 {E1=0, E2=8, E3}; +class X { enum {EE1=-1, EE2, EE3}; }; +

translates to:

E1 EQU 0x00000000 +E2 EQU 0x00000008 +E3 EQU 0x00000009 +X_EE1 EQU 0xFFFFFFFF +X_EE2 EQU 0x00000000 +X_EE3 EQU 0x00000001 +

Offset of a class member within the class

For example:

class X { TInt iX; TInt iY; TInt iZ[16]; };

translates +to:

X_iX EQU 0x00000000 +X_iY EQU 0x00000004 +X_iZ EQU 0x00000008 +X_iZ_spc EQU 0x00000004 +X_sz EQU 0x00000048

The offset of a class +member within the class is given the assembler name <class>_<member>. +For an array member, this offset is the offset of the first element of the +array within the class and <class>_<member>_spc is +the size of each array element. The overall size of the class is given the +assembler name <class>_sz.

When computing these +offsets and sizes the following basic types are known to the translation tool:

TInt8, TUint8 = 1 byteTInt16, TUint16 = 2 bytes aligned to 2 byte boundaryTInt32, TUint32, TInt, TUint, enum, TLinAddr, TPte, TPde = 4 bytes aligned to 4 byte boundaryTInt64, TUint64 = 8 bytes aligned to 8 byte boundary

The +tool will produce an error if an attempt is made to use a TInt64 or TUint64 which +is not aligned on an 8 byte boundary. This is done to avoid incompatibilities +between GCC and EABI compilers since the tool is not aware which is being +used to compile the kernel.