soc/amd/stoneyridge: Use USE_AMD_BLOBS to remove default paths

Remove default path/to/file strings when USE_AMD_BLOBS is not enabled.
This will result in a buildable, but not runable image, in the default
configuration.

Drop the check for HAVE_MERLINFALCON_BINARIES in the path default.
A later patch will address the poor use of this symbol

All PSP blobs are still assumed to be in the same directory as the AMD
public key.  Qualify building the amdfw.rom intermediate image and
including it into coreboot.rom on whether the public key remains "".
This change infers it's OK to skip xHCI and GEC firmware too, although
the images normally reside in a separate directory.

This change only determines whether default paths and names exist.
Paths will be updated in a follow-on patch.

Change-Id: Ic21fbd7a58b340a9bcaaea456e1f38b567215b81
Signed-off-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37220
Reviewed-by: Richard Spiegel <richard.spiegel@silverbackltd.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/amd/stoneyridge/Kconfig

@@ -174,7 +174,8 @@ config VGA_BIOS_ID
 
 config VGA_BIOS_FILE
 	string
-	default "3rdparty/blobs/soc/amd/merlinfalcon/VBIOS.bin" if AMD_APU_MERLINFALCON && HAVE_MERLINFALCON_BINARIES
+	default "" if !USE_AMD_BLOBS
+	default "3rdparty/blobs/soc/amd/merlinfalcon/VBIOS.bin" if AMD_APU_MERLINFALCON
 	default "3rdparty/blobs/soc/amd/stoneyridge/VBIOS.bin"
 
 config S3_VGA_ROM_RUN
@@ -214,6 +215,7 @@ config STONEYRIDGE_GEC_FWM
 
 config STONEYRIDGE_XHCI_FWM_FILE
 	string "XHCI firmware path and filename"
+	default "" if !USE_AMD_BLOBS
 	default "3rdparty/blobs/soc/amd/stoneyridge/xhci.bin"
 	depends on STONEYRIDGE_XHCI_FWM
 
@@ -223,7 +225,8 @@ config STONEYRIDGE_GEC_FWM_FILE
 
 config AMD_PUBKEY_FILE
 	string "AMD public Key"
-	default "3rdparty/blobs/soc/amd/merlinfalcon/PSP/AmdPubKeyCZ.bin" if AMD_APU_MERLINFALCON && HAVE_MERLINFALCON_BINARIES
+	default "" if !USE_AMD_BLOBS
+	default "3rdparty/blobs/soc/amd/merlinfalcon/PSP/AmdPubKeyCZ.bin" if AMD_APU_MERLINFALCON
 	default "3rdparty/blobs/soc/amd/stoneyridge/PSP/AmdPubKeyST.bin"
 
 config STONEYRIDGE_SATA_MODE

src/soc/amd/stoneyridge/Makefile.inc

@@ -137,20 +137,15 @@ STONEYRIDGE_FWM_POSITION=$(call int-add, \
 
 ### 0
 FIRMWARE_LOCATE=$(dir $(call strip_quotes, $(CONFIG_AMD_PUBKEY_FILE)))
+ifneq ($(FIRMWARE_LOCATE),)
 
 ifeq ($(CONFIG_AMD_APU_STONEYRIDGE),y)
 FIRMWARE_TYPE=ST
 else
-
 ifeq ($(CONFIG_AMD_APU_MERLINFALCON),y)
-# If Merlin Falcon, but blobs aren't present, use Stoney Ridge instead
-ifeq ($(CONFIG_HAVE_MERLINFALCON_BINARIES),y)
 FIRMWARE_TYPE=CZ
 else
-FIRMWARE_TYPE=ST
+$(error soc/amd/stoneyridge: Unusable FIRMWARE_TYPE)
-endif # CONFIG_HAVE_MERLINFALCON_BINARIES
-else
-$(error stoneyridge: Unknown FIRMWARE_TYPE)
 
 endif # CONFIG_AMD_APU_MERLINFALCON
 endif # CONFIG_AMD_APU_STONEYRIDGE
@@ -332,4 +327,17 @@ endif
 
 endif # ifeq ($(CONFIG_SOC_AMD_PSP_SELECTABLE_SMU_FW),y)
 
+else # ifneq ($(FIRMWARE_LOCATE),)
+
+warn_no_amdfw:
+	printf "\n\t** WARNING **\n"
+	printf "coreboot has been built with no PSP firmware and "
+	printf "a non-booting image has been generated.\n\n"
+
+PHONY+=warn_no_amdfw
+
+files_added:: warn_no_amdfw
+
+endif # ifneq ($(FIRMWARE_LOCATE),)
+
 endif # ($(CONFIG_SOC_AMD_MERLINFALCON)$(CONFIG_SOC_AMD_STONEYRIDGE_FP4)$(CONFIG_SOC_AMD_STONEYRIDGE_FT4),y)