fconf: Add documentation

Change-Id: I606f9491fb6deebc6845c5b9d7db88fc5c895bd9
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>
diff --git a/docs/resources/diagrams/plantuml/fconf_bl1_load_config.puml b/docs/resources/diagrams/plantuml/fconf_bl1_load_config.puml
new file mode 100644
index 0000000..c36e544
--- /dev/null
+++ b/docs/resources/diagrams/plantuml/fconf_bl1_load_config.puml
@@ -0,0 +1,52 @@
+@startuml
+
+box "BL1 common code"
+	participant bl1_main
+	participant bl_common
+end box
+
+box "arm platform code" #LightBlue
+	participant fvp_bl1_setup
+	participant arm_bl1_setup
+	participant arm_io_storage
+end box
+
+box "platform common code"
+	participant plat_bl1_common
+	participant fconf
+end box
+
+bl1_main -> fvp_bl1_setup : bl1_platform_setup()
+fvp_bl1_setup -> arm_bl1_setup : arm_bl1_platform_setup()
+arm_bl1_setup -> arm_io_storage : plat_arm_io_setup()
+note over arm_io_storage : register and setup fip
+arm_bl1_setup -> fconf : fconf_load_config()
+activate fconf
+	note over fconf
+		create and populate an
+		image_desc_t for TB_FW_CONFIG
+	end note
+	fconf -> bl_common : load_auth_image(TB_FW_CONFIG_ID, &image_info)
+	activate bl_common
+	note over bl_common
+		load and auth image from fip
+		with info from plat_io_policy
+	end note
+	bl_common -> arm_io_storage
+	arm_io_storage -> fconf: FCONF_GET_PROPERTY(arm, arm_io_policies, tb_fw_cfg)
+	note over fconf: use staticaly defined policies in bl1
+	fconf <- bl_common : image_info
+	deactivate bl_common
+	note over fconf : get tb_fw_config_dtb from image_info
+	fconf -> plat_bl1_common : bl1_plat_get_image_desc(BL2_IMAGE_ID)
+	fconf <- plat_bl1_common : BL2_IMAGE_DESC
+	note over fconf
+		set ep_info.args.arg0 of BL2_IMAGE_DESC
+		to TB_FW_CONFIG base address
+	end note
+arm_bl1_setup <- fconf
+deactivate fconf
+
+== load & auth, prepare and jump to BL2 ==
+
+@enduml
diff --git a/docs/resources/diagrams/plantuml/fconf_bl2_populate.puml b/docs/resources/diagrams/plantuml/fconf_bl2_populate.puml
new file mode 100644
index 0000000..98a3ff1
--- /dev/null
+++ b/docs/resources/diagrams/plantuml/fconf_bl2_populate.puml
@@ -0,0 +1,41 @@
+@startuml
+
+box "BL2 common code"
+	participant bl2_entrypoint
+	participant bl2_main
+end box
+
+box "platform common code"
+	participant fconf
+	participant fconf_tbbr_getter
+end box
+
+box "arm platform code" #LightBlue
+	participant arm_bl2_setup
+	participant arm_io_storage
+	participant arm_fconf_io
+end box
+
+== bl2 setup ==
+bl2_entrypoint -> bl2_main : bl2_setup()
+bl2_main -> arm_bl2_setup : bl2_early_platform_setup2(\n\t arg0, arg1, arg2, arg3)
+note over arm_bl2_setup
+	arg0 = tb_fw_config
+	arg1 = mem_layout
+end note
+arm_bl2_setup -> arm_bl2_setup : arm_bl2_early_platform_setup(\n\t tb_fw_config, mem_layout)
+activate arm_bl2_setup
+	arm_bl2_setup -> fconf: fconf_polulate(tb_fw_config)
+	activate fconf
+		fconf -> fconf_tbbr_getter: fconf_populate_tbbr_dyn_config(uintptr_t dtb)
+		note over fconf_tbbr_getter: read tbbr propeties from dtb
+		fconf -> arm_fconf_io: fconf_populate_arm_io_policies(uintptr_t dtb)
+		note over arm_fconf_io: read arm io propeties from dtb
+	deactivate fconf
+	arm_bl2_setup -> arm_io_storage : plat_arm_io_setup()
+	note over arm_io_storage: use populated properties
+deactivate arm_bl2_setup
+
+== bl2 main ==
+
+@enduml