[coreboot-gerrit] New patch to review for coreboot: soc/intel/apollolake: Avoid hardcoding CAR region size for FSPM

[Andrey Petrov (andrey.petrov@intel.com)]

Andrey Petrov (andrey.petrov at intel.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/14001

-gerrit

commit 6fad2891a89eab329a6043be294e42d962068f2c
Author: Andrey Petrov <andrey.petrov at intel.com>
Date:   Tue Mar 8 21:59:01 2016 -0800

    soc/intel/apollolake: Avoid hardcoding CAR region size for FSPM
    
    Instead of having to supply CAR memory region during compilation
    time it is possible to determine it in runtime. FSP2.0 blobs carry
    a copy of UPD structure pre-populated with 'default' values. The
    default value for StackSize is actually the real value blob needs.
    
    Change-Id: I298e07bb12470ce659f63846ab096189138e594f
    Signed-off-by: Andrey Petrov <andrey.petrov at intel.com>
---
 src/soc/intel/apollolake/Kconfig    |  6 ------
 src/soc/intel/apollolake/romstage.c | 12 ++++++++----
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/src/soc/intel/apollolake/Kconfig b/src/soc/intel/apollolake/Kconfig
index 022c2e4..a11c5a2 100644
--- a/src/soc/intel/apollolake/Kconfig
+++ b/src/soc/intel/apollolake/Kconfig
@@ -98,10 +98,4 @@ config ROMSTAGE_ADDR
 	help
 	  The base address (in CAR) where romstage should be linked
 
-config FSPM_STACK_SIZE
-	hex
-	default 0x40000
-	help
-	  The amount of CAR memory FSPM needs. Recommended at least 256KiB
-
 endif
diff --git a/src/soc/intel/apollolake/romstage.c b/src/soc/intel/apollolake/romstage.c
index 2c8bbe8..7c8924d 100644
--- a/src/soc/intel/apollolake/romstage.c
+++ b/src/soc/intel/apollolake/romstage.c
@@ -141,10 +141,14 @@ void platform_fsp_memory_init_params_cb(struct FSPM_UPD *mupd)
 	mupd->FspmConfig.FitTablePtr = read32((void*) FIT_POINTER);
 	/* Reserve enough memory under TOLUD to save CBMEM header */
 	mupd->FspmArchUpd.BootLoaderTolumSize = cbmem_overhead_size();
-	/* Let FSPM use memory right at the top of CAR */
-	/* TODO: Add checks to see if we collide with other areas */
-	mupd->FspmArchUpd.StackBase = _car_region_end - CONFIG_FSPM_STACK_SIZE;
-	mupd->FspmArchUpd.StackSize = CONFIG_FSPM_STACK_SIZE;
+	/*
+	 * FSPM_UPD passed here is populated with default values provided by
+	 * the blob itself. We let FSPM use top of CAR region of the size it
+	 * requests.
+	 * TODO: add checks to avoid overlap/conflict of CAR usage.
+	 */
+	mupd->FspmArchUpd.StackBase = _car_region_end -
+					mupd->FspmArchUpd.StackSize;
 }
 
 __attribute__ ((weak))