drivers/spi: ensure SPI flash is boot device for coreboot tables

The spi_flash_probe() routine was setting a global varible
unconditonally regardless if the probe was for the boot device
or even if the boot devcie was flash. Moreover, there's no need
to report the SPI information if the boot device isn't even SPI.

Lastly, it's possible that the boot device is a SPI flash, but
the platform may never probe (selecting SPI_FLASH) for the
actual device connected. In that situation don't fill anything
in as no correct information is known.

BUG=chrome-os-partner:56151

Change-Id: Ib0eba601df4d77bede313c358c92b0536355bbd0
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/16197
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>

2 files changed, 21 insertions, 10 deletions

diff --git a/src/drivers/spi/spi_flash.c b/src/drivers/spi/spi_flash.c
index 690b277592..60064208d2 100644
--- a/src/drivers/spi/spi_flash.c
+++ b/src/drivers/spi/spi_flash.c
@@ -11,6 +11,7 @@
 #include <cbfs.h>
 #include <cpu/x86/smm.h>
 #include <delay.h>
+#include <rules.h>
 #include <stdlib.h>
 #include <string.h>
 #include <spi-generic.h>
@@ -372,7 +373,13 @@ flash_detected:
 	printk(BIOS_INFO, "SF: Detected %s with sector size 0x%x, total 0x%x\n",
 			flash->name, flash->sector_size, flash->size);
 
-	spi_flash_dev = flash;
+	/*
+	 * Only set the global spi_flash_dev if this is the boot
+	 * device's bus and it's previously unset while in ramstage.
+	 */
+	if (ENV_RAMSTAGE && IS_ENABLED(CONFIG_BOOT_DEVICE_SPI_FLASH) &&
+		CONFIG_BOOT_DEVICE_SPI_FLASH_BUS == bus && !spi_flash_dev)
+		spi_flash_dev = flash;
 
 	return flash;
 
@@ -381,14 +388,13 @@ err_read_id:
 	return NULL;
 }
 
-/* Only the RAM stage will build in the lb_new_record symbol
- * so only define this function if we are after that stage */
-#ifdef __RAMSTAGE__
-
 void lb_spi_flash(struct lb_header *header)
 {
 	struct lb_spi_flash *flash;
 
+	if (!IS_ENABLED(CONFIG_BOOT_DEVICE_SPI_FLASH))
+		return;
+
 	flash = (struct lb_spi_flash *)lb_new_record(header);
 
 	flash->tag = LB_TAG_SPI_FLASH;
@@ -410,5 +416,3 @@ void lb_spi_flash(struct lb_header *header)
 		flash->erase_cmd = CMD_BLOCK_ERASE;
 	}
 }
-
-#endif
diff --git a/src/lib/coreboot_table.c b/src/lib/coreboot_table.c
index 44ae733e9d..f8da6580cb 100644
--- a/src/lib/coreboot_table.c
+++ b/src/lib/coreboot_table.c
@@ -419,6 +419,14 @@ static void lb_record_version_timestamp(struct lb_header *header)
 
 void __attribute__((weak)) lb_board(struct lb_header *header) { /* NOOP */ }
 
+/*
+ * It's possible that the system is using a SPI flash as the boot device,
+ * however it is not probing for devices to fill in specifics. In that
+ * case don't provide any information as the correct information is
+ * not known.
+ */
+void __attribute__((weak)) lb_spi_flash(struct lb_header *header) { /* NOOP */ }
+
 static struct lb_forward *lb_forward(struct lb_header *header, struct lb_header *next_header)
 {
 	struct lb_record *rec;
@@ -532,10 +540,9 @@ static uintptr_t write_coreboot_table(uintptr_t rom_table_end)
 	/* Add RAM config if available */
 	lb_ram_code(head);
 
-#if IS_ENABLED(CONFIG_SPI_FLASH)
 	/* Add SPI flash description if available */
-	lb_spi_flash(head);
-#endif
+	if (IS_ENABLED(CONFIG_BOOT_DEVICE_SPI_FLASH))
+		lb_spi_flash(head);
 
 	add_cbmem_pointers(head);