Re: [U-Boot] [PATCH 1/2] fdt: Avoid early panic() when there is no FDT present

Simon,

-----Original Message----- From: Simon Glass [mailto:sjg@chromium.org] Sent: Wednesday, March 28, 2012 1:08 PM To: U-Boot Mailing List Cc: Tom Warren; Stephen Warren; Albert Aribaud; Simon Glass; Jerry Van Baren; Devicetree Discuss Subject: [PATCH 1/2] fdt: Avoid early panic() when there is no FDT present

CONFIG_OF_CONTROL requires a valid device tree. However, we cannot call panic() before the console is set up since the message does not appear, and we get a silent failure.

Remove the panic from fdtdec_check_fdt() and provide a new function to prepare the fdt for use. This will be called after the console is ready.

Signed-off-by: Simon Glass sjg@chromium.org

Tested-by: Tom Warren twarren@nvidia.com Acked-by: Tom Warren twarren@nvidia.com

---

include/fdtdec.h | 17 +++++++++++++++-- lib/fdtdec.c | 24 +++++++++++++++++++----- 2 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/include/fdtdec.h b/include/fdtdec.h index 766e0bd..d45acbe 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -157,8 +157,21 @@ s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, int fdtdec_get_is_enabled(const void *blob, int node);

/**

• • Checks whether we have a valid fdt available to control U-Boot, and

panic

• • if not.

• • Make sure we have a valid fdt available to control U-Boot.
• • If not, a message is printed to the console if the console is ready.
• • @return 0 if all ok, -1 if not
• */

+int fdtdec_prepare_fdt(void);

+/**

• • Checks that we have a valid fdt available to control U-Boot.
• • However, if not then for the moment nothing is done, since this
• function
• • is called too early to panic().
• • @returns 0
  */

int fdtdec_check_fdt(void);

diff --git a/lib/fdtdec.c b/lib/fdtdec.c index 9241d13..0fb6d17 100644 --- a/lib/fdtdec.c +++ b/lib/fdtdec.c @@ -276,17 +276,31 @@ int fdtdec_add_aliases_for_id(const void *blob, const char *name, return num_found; }

+int fdtdec_check_fdt(void) +{

• /*

• * We must have an FDT, but we cannot panic() yet since the console
  

• * is not ready. So for now, just assert(). Boards which need an
  

early

• * FDT (prior to console ready) will need to make their own
  

• * arrangements and do their own checks.
  

• */
  

• assert(!fdtdec_prepare_fdt());
• return 0;

+}

/*

• This function is a little odd in that it accesses global data. At some
• point if the architecture board.c files merge this will make more sense.
• Even now, it is common code.

*/ -int fdtdec_check_fdt(void) +int fdtdec_prepare_fdt(void) {

• /* We must have an fdt */
• if (((uintptr_t)gd->fdt_blob & 3) || fdt_check_header(gd->fdt_blob))

• panic("No valid fdt found - please append one to U-Boot\n"
  

• 	"binary or define CONFIG_OF_EMBED\n");
  

• if (((uintptr_t)gd->fdt_blob & 3) || fdt_check_header(gd->fdt_blob))

{

• printf("No valid FDT found - please append one to U-Boot "
  

• 	"binary, use u-boot-dtb.bin or define "
  

• 	"CONFIG_OF_EMBED\n");
  

• return -1;
  

• } return 0;

}

-- 1.7.7.3