From: Jeff Johnston <jjohnstn@redhat.com>
To: Nick Clifton <nickc@redhat.com>
Cc: newlib@sourceware.org, binutils@sourceware.org
Subject: Re: RFA: V850: Separate DATA and HEAP memory areas
Date: Tue, 24 May 2011 15:54:00 -0000 [thread overview]
Message-ID: <4DDBD48C.1010804@redhat.com> (raw)
In-Reply-To: <m3ipt1bv39.fsf@redhat.com>
I have no issues with the change. Please go ahead.
-- Jeff J.
On 05/23/2011 05:54 AM, Nick Clifton wrote:
> Hi Jeff,
>
> I would like permission to apply the patch below to the V850 version
> of the sbrk() function in newlib and libgloss. It does two things.
> Firstly it tidies up the code. Secondly it changes the start of the
> heap to be based on the symbol "heap_start" rather than the symbol
> "end". The importance of the second change is that it allows the heap
> to be placed somewhere other than at the end of data. This means that
> on a V850 board with two separate banks of memory, for example, the
> stack and heap can be in one bank and the data in another. Eg:
>
> MEMORY
> {
> ROM : ORIGIN = 0x00001000, LENGTH = 0x001ff000 /* 2Mb */
> RAM2 (w) : ORIGIN = 0xfebf0000, LENGTH = 0x00010000 /* 64k */
> STACK (w) : ORIGIN = 0xfebffff0, LENGTH = 16 /* Top of RAM2 */
> RAM (w) : ORIGIN = 0xfedf0000, LENGTH = 0x00010000 /* 64k */
> }
>
> SECTIONS
> {
> .text :
> {
> *(.text)
> }>ROM =0
>
> .data :
> {
> PROVIDE (__datastart = .);
> *(.data)
> }>RAM AT>ROM
>
> .bss :
> {
> *(.bss)
> PROVIDE (end = .);
> }>RAM
>
> .heap :
> {
> KEEP (*(.heap))
> PROVIDE (_heap_start = .);
> }>RAM2
>
> .stack :
> {
> __stack = .;
> KEEP ( *(.stack) )
> }> STACK
> }
>
> Ok to apply ?
>
> Cheers
> Nick
>
> newlib/ChangeLog
> 2011-05-23 Nick Clifton<nickc@redhat.com>
>
> * libc/sys/sysnecv850/sbrk.c (_sbrk): Tidy code.
> Base start of heap on the "heap_start" symbol.
>
> libgloss/ChangeLog
> 2011-05-23 Nick Clifton<nickc@redhat.com>
>
> * v8500/sbrk.c (_sbrk): Tidy code.
> Base start of heap on the "heap_start" symbol.
>
>
> Index: newlib/libc/sys/sysnecv850/sbrk.c
> ===================================================================
> RCS file: /cvs/src/src/newlib/libc/sys/sysnecv850/sbrk.c,v
> retrieving revision 1.1.1.1
> diff -u -3 -p -r1.1.1.1 sbrk.c
> --- newlib/libc/sys/sysnecv850/sbrk.c 17 Feb 2000 19:39:50 -0000 1.1.1.1
> +++ newlib/libc/sys/sysnecv850/sbrk.c 23 May 2011 09:38:00 -0000
> @@ -3,34 +3,27 @@
> #include<sys/stat.h>
> #include "sys/syscall.h"
>
> -int errno;
> -
> -int __trap0 (int function, int p1, int p2, int p3);
> -
> -#define TRAP0(f, p1, p2, p3) __trap0(f, (int)(p1), (int)(p2), (int)(p3))
> -
> caddr_t
> _sbrk (int incr)
> {
> - extern char end; /* Defined by the linker */
> - static char *heap_end;
> - char *prev_heap_end;
> -#if 0
> - char *sp = (char *)stack_ptr;
> -#else
> - char *sp = (char *)&sp;
> -#endif
> + extern char heap_start; /* Defined by the linker script. */
> + static char * heap_end = NULL;
> + char * prev_heap_end;
> + char * sp = (char *)& sp;
> +
> + if (heap_end == NULL)
> + heap_end =& heap_start;
>
> - if (heap_end == 0)
> - {
> - heap_end =&end;
> - }
> prev_heap_end = heap_end;
> +
> if (heap_end + incr> sp)
> {
> - _write (1, "Heap and stack collision\n", 25);
> +#define MESSAGE "Heap and stack collision\n"
> + _write (1, MESSAGE, sizeof MESSAGE);
> abort ();
> }
> +
> heap_end += incr;
> +
> return (caddr_t) prev_heap_end;
> }
> Index: libgloss/v850/sbrk.c
> ===================================================================
> RCS file: /cvs/src/src/libgloss/v850/sbrk.c,v
> retrieving revision 1.1
> diff -u -3 -p -r1.1 sbrk.c
> --- libgloss/v850/sbrk.c 23 Jul 2010 17:52:37 -0000 1.1
> +++ libgloss/v850/sbrk.c 23 May 2011 09:38:00 -0000
> @@ -3,34 +3,27 @@
> #include<sys/stat.h>
> #include "sys/syscall.h"
>
> -int errno;
> -
> -int __trap0 (int function, int p1, int p2, int p3);
> -
> -#define TRAP0(f, p1, p2, p3) __trap0(f, (int)(p1), (int)(p2), (int)(p3))
> -
> caddr_t
> _sbrk (int incr)
> {
> - extern char end; /* Defined by the linker */
> - static char *heap_end;
> - char *prev_heap_end;
> -#if 0
> - char *sp = (char *)stack_ptr;
> -#else
> - char *sp = (char *)&sp;
> -#endif
> + extern char heap_start; /* Defined by the linker script. */
> + static char * heap_end = NULL;
> + char * prev_heap_end;
> + char * sp = (char *)& sp;
> +
> + if (heap_end == NULL)
> + heap_end =& heap_start;
>
> - if (heap_end == 0)
> - {
> - heap_end =&end;
> - }
> prev_heap_end = heap_end;
> +
> if (heap_end + incr> sp)
> {
> - _write (1, "Heap and stack collision\n", 25);
> +#define MESSAGE "Heap and stack collision\n"
> + _write (1, MESSAGE, sizeof MESSAGE);
> abort ();
> }
> +
> heap_end += incr;
> +
> return (caddr_t) prev_heap_end;
> }
>
> PPS. Assuming that you approve the newlib/libgloss patch, I will apply
> this patch to the linker sources:
>
> Index: ld/scripttempl/v850.sc
> ===================================================================
> RCS file: /cvs/src/src/ld/scripttempl/v850.sc,v
> retrieving revision 1.10
> diff -u -3 -p -r1.10 v850.sc
> --- ld/scripttempl/v850.sc 10 Feb 2011 08:18:58 -0000 1.10
> +++ ld/scripttempl/v850.sc 23 May 2011 09:38:00 -0000
> @@ -180,6 +180,7 @@ SECTIONS
>
> ${RELOCATING+_end = . ;}
> ${RELOCATING+PROVIDE (end = .);}
> + ${RELOCATING+PROVIDE (_heap_start = .);}
>
> /* Stabs debugging sections. */
> .stab 0 : { *(.stab) }
>
prev parent reply other threads:[~2011-05-24 15:54 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-23 9:54 Nick Clifton
2011-05-24 15:54 ` Jeff Johnston [this message]
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