[U-Boot] [PATCH v8 12/30] sandbox: Try to start the RAM buffer at a particular address

[Alexander Graf <agraf@suse.de>]

On 06/18/2018 04:08 PM, Simon Glass wrote:
> Use a starting address of 256MB which should be available. This helps to
> make sandbox RAM buffers pointers more recognisable.
>
> Signed-off-by: Simon Glass <sjg@chromium.org>

Nak, this has a non-0 chance of failing, in case something else is 
already mapped at that address. You don't want to have your CI blow up 
1% of the time due to this.


Alex

> ---
>
> Changes in v8: None
> Changes in v7: None
> Changes in v6: None
> Changes in v5: None
> Changes in v4: None
> Changes in v3: None
> Changes in v2: None
>
>   arch/sandbox/cpu/os.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
> index a1a982af2d..1553aa687d 100644
> --- a/arch/sandbox/cpu/os.c
> +++ b/arch/sandbox/cpu/os.c
> @@ -145,7 +145,12 @@ void *os_malloc(size_t length)
>   	struct os_mem_hdr *hdr;
>   	int page_size = getpagesize();
>   
> -	hdr = mmap(NULL, length + page_size,
> +	/*
> +	 * Use an address that is hopefully available to us so that pointers
> +	 * to this memory are fairly obvious. If we end up with a different
> +	 * address, that's fine too.
> +	 */
> +	hdr = mmap((void *)0x10000000, length + page_size,
>   		   PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
>   	if (hdr == MAP_FAILED)
>   		return NULL;