Specifications

178 www.xilinx.com Embedded System Tools Guide (EDK 6.2i)

1-800-255-7778 UG111 (v1.4) January 30, 2004

Chapter 11: GNU Compiler Tools

PowerPC GNU Compiler

Compiler Options

The PowerPC GNU compiler (powerpc-eabi-gcc) is built using the GNU gcc version

2.95.3-4. No enhancements have been done to the compiler. The PowerPC compiler does

not support any special options. All the listed common options are supported by the

powerpc-eabi compiler.

Linker Options

-defsym _START_ADDR=value

By default, the text section of the output code starts with the base address 0xffff0000, since

this is the start address indicated in the default linker script. This can be overridden by

x using the above option OR

x providing a linker script, which lists the value for start address

The user does not have to use -defsym _START_ADDR, if they wish to use the default

start address set by the compiler.

This is a linker option and should be used when the user is invoking the linker separately.

If the linker is being invoked as a part of the powerpc-eabi-gcc flow, the user has to use the

following option

-Wl,-defsym -Wl,_START_ADDR=value

Initialization Files

The compiler looks for certain initialization files (such as boot.o, crt0.o). These files are

compiled along with the drivers and archived in libxil.a library. This library is generated

using LibGen by compiling the distributed sources in the Board Support Package (BSP).

For more information about LibGen, please refer to Chapter 7, “Library Generator”.

Table 11-8: Use of attributes

Attributes Functions

interrupt_handler This attribute saves the machine status register and all the

volatiles in addition to the non-volatile registers. rtid is

used for returning from the interrupt handler. If the interrupt

handler function is a leaf function, only those volatiles which

are used by the function are saved.

save_volatiles This attribute is similar to interrupt_handler, but it used

rtsd to return to the interrupted function, instead of rtid.