Increase default size of UBI read-write volume

The default size of the UBI read-write volume is currently set to 4MB.
There are no plans to store more than one BMC rootfs image on the chip
so in a 32MB flash chip, accounting for the current rootfs image size
of ~15MB with plans to grow to ~20MB with the addition of redfish and
other packages, it is safe to increase the read-write volume size to
6MB since the current size is already almost completely taken up if
there are multiple error logs / dumps on the system.

In addition, make the size configurable from a recipe so that the
size can be changed in a per-system basis. And during code update,
check the current size and update it if it's different, this allows
systems to be able to be resized to a new size by performing factory
reset after a code update that sets the new size.

Tested:
- Booted on QEMU and verified non-ubi system (romulus) retains the
current 4MB read-write volume, and ubi system (witherspoon) has a
6MB volume.
- Code updated to an image that has these changes and verified the
rwfs_size env variable changes to 6MB, and that a subsequent factory
reset rebuilds the volume with size 6MB.

Change-Id: I995eb560c1bd87ee95712c731e3d6e55bc0b2735
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/meta-phosphor/common/recipes-phosphor/flash/phosphor-software-manager.bb b/meta-phosphor/common/recipes-phosphor/flash/phosphor-software-manager.bb
index 5cd017e18..725c83577 100644
--- a/meta-phosphor/common/recipes-phosphor/flash/phosphor-software-manager.bb
+++ b/meta-phosphor/common/recipes-phosphor/flash/phosphor-software-manager.bb
@@ -86,9 +86,11 @@ SYSTEMD_SERVICE_${PN}-updater += " \
 BMC_RW_MTD ??= "bmc"
 BMC_RO_MTD ??= "bmc"
 BMC_KERNEL_MTD ??= "bmc"
+BMC_RW_SIZE ??= "0x600000"
 SYSTEMD_SUBSTITUTIONS += "RW_MTD:${BMC_RW_MTD}:obmc-flash-bmc-ubirw.service"
 SYSTEMD_SUBSTITUTIONS += "RO_MTD:${BMC_RO_MTD}:obmc-flash-bmc-ubiro@.service"
 SYSTEMD_SUBSTITUTIONS += "KERNEL_MTD:${BMC_KERNEL_MTD}:obmc-flash-bmc-ubiro@.service"
+SYSTEMD_SUBSTITUTIONS += "RW_SIZE:${BMC_RW_SIZE}:obmc-flash-bmc-ubirw.service"
 
 SRC_URI += "file://obmc-flash-bmc"
 do_install_append() {