Subj : where can I find a malloc for standalone programs ?
To   : comp.programming
From : DEMAINE Benoit-Pierre
Date : Fri Aug 19 2005 08:40 pm

I am writing a program for standalone use; the circuit in configured with some
bootstrap, then my code is called.

There is no Linux, nor filesyem, nor libraries around.

my code is statically compiled and linked with gcc.

problem occurs about malloc: since there is no kernel, nor system, nor stdlib, there
is no malloc defined. I can not either link my application against a stdlib stolen
to any system, since I have no kernel, and that stdlib would not know the addresses
of memory pages available.

Thus, I need a new malloc that is initialised by a special initialisation call, with
begin and end adresses of memory space, and implements malloc() and free(), and is
aware of endianness, bus width, alignment problems ...

It would be a plus if some internal function could return the amount of alocated
zones, so that I can track memory consumption, and expect/track leakages.

The memory pages available are not all memory locations wired on the board. the
bootstrap requires about 50% for internal use, and interrupt management. I have the
upper 50% for me.

The CPU stack is stored somewhere else, not sure exactly where in fact :S

Problem is that my code requires some bits of dynamically allocated variables and
arrays, so that I really need malloc; I hope I spend less time implementing malloc
than trying to port the code to use only fixed allocations.

Inside my zone, I need to allocate for personnal use some pages (about 200kB, to
store constants, and exchange values with interrupts). These pages shall NOT be
managed by malloc; they are managed manually when I write my source.

I am using at the moment GCC-bare-metal from
http://www.codesourcery.com/gnu_toolchains/arm/, with Gentoo-x86 as host, and a
Cogent CSB336 MC9328MXL as target: ARM920T with RAM, FLASH, and various devices.

I can only use GPL and public programs, softwares, and libraries.

Thanks for any help, URL, books, sneekers, check, tip ... :p
-- 
DEMAINE Benoit-Pierre (aka DoubleHP ) http://www.demaine.info/
\_o< If computing were an exact science, IT engineers would not have work >o_/

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