acpi: Hide Chrome and coreboot specific devices

Some ACPI interfaces introduced by Chrome or coreboot do not
need drivers outside ChromeOS, for example Chrome EC or
coreboot table; or will be probed by direct ACPI calls (instead
of trying to find drivers by device IDs).

These interfaces should be set to hidden so non-ChromeOS systems,
for example Windows, won't have problem finding driver.

Interfaces changed:
- coreboot (BOOT0000), only used by Chrome OS / Linux kernel.
- Chrome OS EC
- Chrome OS EC PD
- Chrome OS TBMC
- Chrome OS RAMoops

BUG=b:72200466
BRANCH=eve
TEST=Boot into non-ChromeOS systems (for example Windows)
     and checked ACPI devices on UI.

Change-Id: I9786cf9ee07b2c3f11509850604f2bfb3f3e710a
Signed-off-by: David Wu <David_Wu@quanta.corp-partner.google.com>
Reviewed-on: https://chromium-review.googlesource.com/1078211
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Commit-Queue: Hung-Te Lin <hungte@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
Trybot-Ready: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: https://review.coreboot.org/28333
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/src/vendorcode/google/chromeos/acpi/ramoops.asl b/src/vendorcode/google/chromeos/acpi/ramoops.asl
index 5a8ed86632..810ff91a01 100644
--- a/src/vendorcode/google/chromeos/acpi/ramoops.asl
+++ b/src/vendorcode/google/chromeos/acpi/ramoops.asl
@@ -35,5 +35,9 @@ Scope (\_SB)
 			Store (\RMOL, RLEN)
 			Return (^RBUF)
 		}
+		Method(_STA, 0)
+		{
+			Return (0xB)
+		}
 	}
 }