drivers/intel/fsp2_0: Support embedding a second FSP-M/FSP-S

Support embedding a second FSP-M/FSP-S binary for an SoC that can
select one at runtime.

Comet Lake v1 and v2 are different steppings of the same SKUs, but they
require different FSP binaries.  Supporting both in a single build
requires embedding both FSPs and selecting one at runtime based on the
CPUID.  This is desirable for a product that may have different CPU
steppings but is not otherwise differentiated enough for a separate
firmware build.

An SoC can select PLATFORM_USES_SECOND_FSP to indicate that two FSP-M/
FSP-S binaries are required.  Implement soc_select_fsp_m_cbfs() and
soc_select_fsp_s_cbfs() to choose one based on platform-specific
criteria.  For Comet Lake, the first FSP is CML v1 and the second is
CML v2, but in principle a platform could define any meaning for the
first and second FSP.

FSP-T is not affected, only one FSP-T can be embedded if FSP_CAR is
used.

Only one set of FSP headers is used, which is sufficient for Comet Lake
v1/v2; their headers are equivalent.

ADD_FSP_BINARIES, FSP_USE_REPO, and FSP_FULL_FD are supported for both
sets of FSP-S/FSP-M but cannot be configured separately, both use the
same configuration.

Change-Id: Ied4c6c49a6bdf278238272edd47a2006258be8e5
Signed-off-by: Jonathon Hall <jonathon.hall@puri.sm>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78344
Reviewed-by: Michał Kopeć <michal.kopec@3mdeb.com>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin L Roth <gaumless@gmail.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/src/drivers/intel/fsp2_0/include/fsp/util.h b/src/drivers/intel/fsp2_0/include/fsp/util.h
index 75b9ad844e..acf337f661 100644
--- a/src/drivers/intel/fsp2_0/include/fsp/util.h
+++ b/src/drivers/intel/fsp2_0/include/fsp/util.h
@@ -179,6 +179,21 @@ void fsp_handle_reset(uint32_t status);
 /* SoC/chipset must provide this to handle platform-specific reset codes */
 void chipset_handle_reset(uint32_t status);
 
+#if CONFIG(PLATFORM_USES_SECOND_FSP)
+/* The SoC must implement these to choose the appropriate FSP-M/FSP-S binary. */
+const char *soc_select_fsp_m_cbfs(void);
+const char *soc_select_fsp_s_cbfs(void);
+#else
+static inline const char *soc_select_fsp_m_cbfs(void)
+{
+	return CONFIG_FSP_M_CBFS;
+}
+static inline const char *soc_select_fsp_s_cbfs(void)
+{
+	return CONFIG_FSP_S_CBFS;
+}
+#endif
+
 typedef asmlinkage uint32_t (*temp_ram_exit_fn)(void *param);
 typedef asmlinkage uint32_t (*fsp_memory_init_fn)
 				   (void *raminit_upd, void **hob_list);