[PATCH 12] SPARC BSPs: bsp_early_malloc() routine for startup memory allocation
Joel Sherrill
joel.sherrill at OARcorp.com
Tue Mar 27 20:54:21 UTC 2012
On 03/27/2012 03:36 PM, Gedare Bloom wrote:
> I'm willing to take this patch as-is and consider refactoring it later
> to share the code with other BSPs if the feature seems generally
> useful. Joel?
I don't see any reason not to. The LEON is very dynamic in
the way it finds its on-CPU devices. Most BSPs will not have
this issue. I don't expect many other BSPs to need this
capability.
If other BSPs need something similar, then the bsp_early_malloc()
can likely be implemented in a similar manner based upon how
the memory is allocated on the BSP. There are only a handful
of patterns. If that happens, we can probably implement one
as a "partner" to bsp_get_workspace() implementations. Since
the SPARC BSPs share a single implementation, I think this is
good enough for now.
Can the method's comments be enhanced to note that it is
ONLY to be used from point X to point Y during the initialization
sequence?
And kill the $Id's. At least one is broken anyway.
--joel
> -Gedare
>
> On Mon, Feb 6, 2012 at 11:08 AM, Daniel Hellstrom<daniel at gaisler.com> wrote:
>> On 02/06/2012 04:45 PM, Gedare Bloom wrote:
>>> On Mon, Feb 6, 2012 at 9:15 AM, Daniel Hellstrom<daniel at gaisler.com>
>>> wrote:
>>>> If bsp_early_malloc() is called early during boot room will be
>>>> allocated after BSS END. If the function is called after boot
>>>> is will call malloc() instead. The returned memory is not freeable
>>>> and always 8-byte aligned.
>>>>
>>>> If the bsp_early_malloc() isn't called the function is not
>>>> dragged in and the workspace will be unmodified in size.
>>>>
>>>> Signed-off-by: Daniel Hellstrom<daniel at gaisler.com>
>>>> ---
>>>> c/src/lib/libbsp/sparc/erc32/Makefile.am | 2 +-
>>>> c/src/lib/libbsp/sparc/erc32/include/bsp.h | 3 +
>>>> c/src/lib/libbsp/sparc/leon2/Makefile.am | 3 +-
>>>> c/src/lib/libbsp/sparc/leon2/include/bsp.h | 3 +
>>>> c/src/lib/libbsp/sparc/leon3/Makefile.am | 2 +-
>>>> c/src/lib/libbsp/sparc/leon3/include/bsp.h | 3 +
>>>> c/src/lib/libbsp/sparc/shared/bspgetworkarea.c | 10 ++++-
>>>> .../lib/libbsp/sparc/shared/startup/early_malloc.c | 44
>>>> ++++++++++++++++++++
>>>> 8 files changed, 65 insertions(+), 5 deletions(-)
>>>> create mode 100644 c/src/lib/libbsp/sparc/shared/startup/early_malloc.c
>>>>
>>>> diff --git a/c/src/lib/libbsp/sparc/erc32/Makefile.am
>>>> b/c/src/lib/libbsp/sparc/erc32/Makefile.am
>>>> index cecfe14..e70310d 100644
>>>> --- a/c/src/lib/libbsp/sparc/erc32/Makefile.am
>>>> +++ b/c/src/lib/libbsp/sparc/erc32/Makefile.am
>>>> @@ -38,7 +38,7 @@ libbsp_a_SOURCES += ../../shared/bspclean.c
>>>> ../../shared/bsplibc.c \
>>>> ../../shared/bspstart.c ../../shared/bootcard.c
>>>> ../../shared/bspinit.c \
>>>> ../../shared/sbrk.c startup/setvec.c startup/spurious.c \
>>>> startup/erc32mec.c startup/boardinit.S startup/bspidle.c \
>>>> - startup/bspdelay.c
>>>> + startup/bspdelay.c ../../sparc/shared/startup/early_malloc.c
>>>> # ISR Handler
>>>> libbsp_a_SOURCES += ../../sparc/shared/irq_asm.S
>>>> # gnatsupp
>>>> diff --git a/c/src/lib/libbsp/sparc/erc32/include/bsp.h
>>>> b/c/src/lib/libbsp/sparc/erc32/include/bsp.h
>>>> index 8655732..8075e8e 100644
>>>> --- a/c/src/lib/libbsp/sparc/erc32/include/bsp.h
>>>> +++ b/c/src/lib/libbsp/sparc/erc32/include/bsp.h
>>>> @@ -81,6 +81,9 @@ void BSP_fatal_return( void );
>>>>
>>>> void bsp_spurious_initialize( void );
>>>>
>>>> +/* Allocate 8-byte aligned non-freeable pre-malloc memory */
>>>> +void *bsp_early_malloc(int size);
>>>> +
>>>> #ifdef __cplusplus
>>>> }
>>>> #endif
>>>> diff --git a/c/src/lib/libbsp/sparc/leon2/Makefile.am
>>>> b/c/src/lib/libbsp/sparc/leon2/Makefile.am
>>>> index 9df3c7d..6e2697f 100644
>>>> --- a/c/src/lib/libbsp/sparc/leon2/Makefile.am
>>>> +++ b/c/src/lib/libbsp/sparc/leon2/Makefile.am
>>>> @@ -55,7 +55,8 @@ libbsp_a_SOURCES += ../../shared/bspclean.c
>>>> ../../shared/bsplibc.c \
>>>> startup/bspstart.c ../../sparc/shared/bsppretaskinghook.c \
>>>> ../../sparc/shared/bspgetworkarea.c ../../shared/bootcard.c \
>>>> ../../shared/sbrk.c startup/setvec.c startup/spurious.c
>>>> startup/bspidle.c \
>>>> - ../../shared/bspinit.c startup/bspdelay.c
>>>> + ../../shared/bspinit.c startup/bspdelay.c \
>>>> + ../../sparc/shared/startup/early_malloc.c
>>>> # ISR Handler
>>>> libbsp_a_SOURCES += ../../sparc/shared/irq_asm.S
>>>> # gnatsupp
>>>> diff --git a/c/src/lib/libbsp/sparc/leon2/include/bsp.h
>>>> b/c/src/lib/libbsp/sparc/leon2/include/bsp.h
>>>> index 34e31ce..b0695cb 100644
>>>> --- a/c/src/lib/libbsp/sparc/leon2/include/bsp.h
>>>> +++ b/c/src/lib/libbsp/sparc/leon2/include/bsp.h
>>>> @@ -94,6 +94,9 @@ void BSP_fatal_return( void );
>>>>
>>>> void bsp_spurious_initialize( void );
>>>>
>>>> +/* Allocate 8-byte aligned non-freeable pre-malloc memory */
>>>> +void *bsp_early_malloc(int size);
>>>> +
>>>> #ifdef __cplusplus
>>>> }
>>>> #endif
>>>> diff --git a/c/src/lib/libbsp/sparc/leon3/Makefile.am
>>>> b/c/src/lib/libbsp/sparc/leon3/Makefile.am
>>>> index 8eae306..dc24051 100644
>>>> --- a/c/src/lib/libbsp/sparc/leon3/Makefile.am
>>>> +++ b/c/src/lib/libbsp/sparc/leon3/Makefile.am
>>>> @@ -38,7 +38,7 @@ libbsp_a_SOURCES += ../../shared/bspclean.c
>>>> ../../shared/bsplibc.c \
>>>> ../../sparc/shared/bsppretaskinghook.c
>>>> ../../shared/bsppredriverhook.c \
>>>> ../../sparc/shared/bspgetworkarea.c ../../shared/sbrk.c
>>>> startup/setvec.c \
>>>> startup/spurious.c startup/bspidle.S startup/bspdelay.c \
>>>> - ../../shared/bspinit.c
>>>> + ../../shared/bspinit.c ../../sparc/shared/startup/early_malloc.c
>>>>
>>>> # ISR Handler
>>>> libbsp_a_SOURCES += ../../sparc/shared/irq_asm.S
>>>> diff --git a/c/src/lib/libbsp/sparc/leon3/include/bsp.h
>>>> b/c/src/lib/libbsp/sparc/leon3/include/bsp.h
>>>> index 89b36d4..70ab8b3 100644
>>>> --- a/c/src/lib/libbsp/sparc/leon3/include/bsp.h
>>>> +++ b/c/src/lib/libbsp/sparc/leon3/include/bsp.h
>>>> @@ -104,6 +104,9 @@ void BSP_fatal_return( void );
>>>>
>>>> void bsp_spurious_initialize( void );
>>>>
>>>> +/* Allocate 8-byte aligned non-freeable pre-malloc memory */
>>>> +void *bsp_early_malloc(int size);
>>>> +
>>>> #ifdef __cplusplus
>>>> }
>>>> #endif
>>>> diff --git a/c/src/lib/libbsp/sparc/shared/bspgetworkarea.c
>>>> b/c/src/lib/libbsp/sparc/shared/bspgetworkarea.c
>>>> index c6e1491..580a911 100644
>>>> --- a/c/src/lib/libbsp/sparc/shared/bspgetworkarea.c
>>>> +++ b/c/src/lib/libbsp/sparc/shared/bspgetworkarea.c
>>>> @@ -22,6 +22,9 @@
>>>> /* Tells us where to put the workspace in case remote debugger is
>>>> present. */
>>>> extern uint32_t rdb_start;
>>>>
>>>> +/* Must be aligned to 8, _end is aligned to 8 */
>>>> +unsigned int early_mem = (unsigned int)&end;
>>>> +
>>>> /*
>>>> * This method returns the base address and size of the area which
>>>> * is to be allocated between the RTEMS Workspace and the C Program
>>>> @@ -37,8 +40,11 @@ void bsp_get_work_area(
>>>> /* must be identical to STACK_SIZE in start.S */
>>>> #define STACK_SIZE (16 * 1024)
>>>>
>>>> - *work_area_start =&end;
>>>> - *work_area_size = (void *)rdb_start - (void *)&end - STACK_SIZE;
>>>> + /* Early dynamic memory allocator is placed just above _end */
>>>> + *work_area_start = (void *)early_mem;
>>>> + *work_area_size = (void *)rdb_start - (void *)early_mem - STACK_SIZE;
>>>> + early_mem = ~0; /* Signal bsp_early_malloc not to be used
>>>> anymore */
>>>> +
>>>> *heap_start = BSP_BOOTCARD_HEAP_USES_WORK_AREA;
>>>> *heap_size = BSP_BOOTCARD_HEAP_SIZE_DEFAULT;
>>>>
>>>> diff --git a/c/src/lib/libbsp/sparc/shared/startup/early_malloc.c
>>>> b/c/src/lib/libbsp/sparc/shared/startup/early_malloc.c
>>>> new file mode 100644
>>>> index 0000000..c6abaca
>>>> --- /dev/null
>>>> +++ b/c/src/lib/libbsp/sparc/shared/startup/early_malloc.c
>>>> @@ -0,0 +1,44 @@
>>>> +/*
>>>> + * Early dynamic memory allocation (not freeable) for BSP
>>>> + * boot routines. Minimum alignment 8 bytes. Memory is
>>>> + * allocated after _end, it will shrink the workspace.
>>>> + *
>>>> + * COPYRIGHT (c) 2011.
>>>> + * Aeroflex Gaisler AB
>>>> + *
>>>> + * The license and distribution terms for this file may be
>>>> + * found in the file LICENSE in this distribution or at
>>>> + * http://www.rtems.com/license/LICENSE.
>>>> + *
>>>> + * $Id: early_malloc.c
>>>> + */
>>>> +
>>>> +#include<bsp.h>
>>>> +#include<stdlib.h>
>>>> +
>>>> +/* Tells us where to put the workspace in case remote debugger is
>>>> present. */
>>>> +extern uint32_t rdb_start;
>>>> +
>>>> +/* Must be aligned to 8 */
>>>> +extern unsigned int early_mem;
>>>> +
>>>> +/* must be identical to STACK_SIZE in start.S */
>>>> +#define STACK_SIZE (16 * 1024)
>>>> +
>>>> +void *bsp_early_malloc(int size)
>>>> +{
>>>> + void *start;
>>>> +
>>>> + /* Not early anymore? */
>>>> + if (early_mem == ~0)
>>>> + return malloc(size);
>>>> +
>>>> + size = (size + 7)& ~0x7;
>>>>
>>>> + if (rdb_start - STACK_SIZE - early_mem< size)
>>>> + return NULL;
>>>> +
>>>> + start = (void *)early_mem;
>>>> + early_mem += size;
>>>> +
>>>> + return start;
>>>> +}
>>>> --
>>>> 1.7.0.4
>>>>
>>>> _______________________________________________
>>>> rtems-devel mailing list
>>>> rtems-devel at rtems.org
>>>> http://www.rtems.org/mailman/listinfo/rtems-devel
>>> This looks OK to me. Basic bump allocation for early dynamic memory.
>>> workspace is properly adjusted. If the BSP exhausts memory then RTEMS
>>> should fail gracefully during bootup when it detects the workspace is
>>> not big enough.
>>>
>>> I wonder if there would be any use in having this early memory
>>> mechanism available on every BSP? For what do you use it?
>> I will use it later in a AMBA Plug&Play layer patch.
>>
>> The LEON3/4 is plug and play, one never knows how many cores are available
>> on boot, the PnP layers scan the plug&play info and creates one "RAM
>> structure" description per PnP entry. Before this was made by allocating a
>> worst-case structure in leon3/amba/amba.c (amba_confarea_type amba_conf)
>> which could hold lots of RAM descriptions. However on small systems its a
>> waste, and on very large systems it breaks. Using malloc() would require BSP
>> initialization too late and malloc() wastes 4 or 8-bytes per allocation of
>> memory that we never would have freed anyway.
>>
>> It can probably be useful for other BSPs as well.
>>
>> Daniel
--
Joel Sherrill, Ph.D. Director of Research& Development
joel.sherrill at OARcorp.com On-Line Applications Research
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