cbmem: rename vdat to chromeos_acpi

There is a confusingly named section in cbmem called vdat.
This section holds a data structure called chromeos_acpi_t,
which exposes some system information to the Chrome OS
userland utility crossystem.

Within the chromeos_acpi_t structure, there is a member
called vdat.  This (currently) holds a VbSharedDataHeader.

Rename the outer vdat to chromeos_acpi to make its purpose
clear, and prevent the bizarreness of being able to access
vdat->vdat.

Additionally, disallow external references to the
chromeos_acpi data structure in gnvs.c.

BUG=b:112288216
TEST=emerge-eve coreboot, run on eve
CQ-DEPEND=CL:1164722

Change-Id: Ia74e58cde21678f24b0bb6c1ca15048677116b2e
Signed-off-by: Joel Kitching <kitching@google.com>
Reviewed-on: https://review.coreboot.org/27888
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

2 files changed, 24 insertions, 17 deletions

diff --git a/src/vendorcode/google/chromeos/gnvs.c b/src/vendorcode/google/chromeos/gnvs.c
index a278b4109c..70aa899042 100644
--- a/src/vendorcode/google/chromeos/gnvs.c
+++ b/src/vendorcode/google/chromeos/gnvs.c
@@ -27,40 +27,46 @@
 #include "chromeos.h"
 #include "gnvs.h"
 
-chromeos_acpi_t *vboot_data = NULL;
+static chromeos_acpi_t *chromeos_acpi;
 static u32 me_hash_saved[8];
 
-void chromeos_init_vboot(chromeos_acpi_t *chromeos)
+void chromeos_init_vboot(chromeos_acpi_t *init)
 {
-	vboot_data = chromeos;
+	chromeos_acpi = init;
 
 	/* Copy saved ME hash into NVS */
-	memcpy(vboot_data->mehh, me_hash_saved, sizeof(vboot_data->mehh));
+	memcpy(chromeos_acpi->mehh, me_hash_saved, sizeof(chromeos_acpi->mehh));
 
 	struct vboot_handoff *vboot_handoff;
 
 	if (vboot_get_handoff_info((void **)&vboot_handoff, NULL) == 0)
-		memcpy(&chromeos->vdat[0], &vboot_handoff->shared_data[0],
-		       ARRAY_SIZE(chromeos->vdat));
+		memcpy(&chromeos_acpi->vdat[0], &vboot_handoff->shared_data[0],
+		       ARRAY_SIZE(chromeos_acpi->vdat));
 
-	chromeos_ram_oops_init(chromeos);
+	chromeos_ram_oops_init(chromeos_acpi);
 }
 
 void chromeos_set_me_hash(u32 *hash, int len)
 {
-	if ((len*sizeof(u32)) > sizeof(vboot_data->mehh))
+	if ((len*sizeof(u32)) > sizeof(chromeos_acpi->mehh))
 		return;
 
 	/* Copy to NVS or save until it is ready */
-	if (vboot_data)
+	if (chromeos_acpi)
 		/* This does never happen! */
-		memcpy(vboot_data->mehh, hash, len*sizeof(u32));
+		memcpy(chromeos_acpi->mehh, hash, len*sizeof(u32));
 	else
 		memcpy(me_hash_saved, hash, len*sizeof(u32));
 }
 
-void acpi_get_vdat_info(uint64_t *vdat_addr, uint32_t *vdat_size)
+void acpi_get_chromeos_acpi_info(uint64_t *chromeos_acpi_addr,
+				 uint32_t *chromeos_acpi_size)
 {
-	*vdat_addr = (intptr_t)vboot_data;
-	*vdat_size = sizeof(*vboot_data);
+	*chromeos_acpi_addr = (intptr_t)chromeos_acpi;
+	*chromeos_acpi_size = sizeof(*chromeos_acpi);
+}
+
+chromeos_acpi_t *acpi_get_chromeos_acpi(void)
+{
+	return chromeos_acpi;
 }
diff --git a/src/vendorcode/google/chromeos/gnvs.h b/src/vendorcode/google/chromeos/gnvs.h
index 82cd409e8e..e865c0e832 100644
--- a/src/vendorcode/google/chromeos/gnvs.h
+++ b/src/vendorcode/google/chromeos/gnvs.h
@@ -53,7 +53,7 @@ typedef struct {
 	u32	vbt7;		// 18e active main firmware type
 	u32	vbt8;		// 192 recovery reason
 	u32	vbt9;		// 196 fmap base address
-	u8	vdat[3072];	// 19a
+	u8	vdat[3072];	// 19a VDAT space filled by verified boot
 	u32	vbt10;		// d9a smbios bios version
 	u32	mehh[8];	// d9e management engine hash
 	u32	ramoops_base;	// dbe ramoops base address
@@ -61,9 +61,10 @@ typedef struct {
 	u8	pad[314];	// dc6-eff
 } __packed chromeos_acpi_t;
 
-extern chromeos_acpi_t *vboot_data;
-void chromeos_init_vboot(chromeos_acpi_t *chromeos);
+void chromeos_init_vboot(chromeos_acpi_t *init);
 void chromeos_set_me_hash(u32*, int);
-void acpi_get_vdat_info(uint64_t *vdat_addr, uint32_t *vdat_size);
+void acpi_get_chromeos_acpi_info(uint64_t *chromeos_acpi_addr,
+				 uint32_t *chromeos_acpi_size);
+chromeos_acpi_t *acpi_get_chromeos_acpi(void);
 
 #endif