[M] Change in coreboot[main]: acpi/acpi.c: fix XSDT handling on QEMU

[Krystian Hebel (Code Review)]

Attention is currently required from: Cliff Huang, Lance Zhao, Tim Wawrzynczak.

Krystian Hebel has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/82698?usp=email )

Change subject: acpi/acpi.c: fix XSDT handling on QEMU
......................................................................

acpi/acpi.c: fix XSDT handling on QEMU

c2830c9 "acpi.c: Add XSDT on QEMU" added a code that copied RSDT to
XSDT since QEMU doesn't generate the latter. However, this new code
didn't move 'current' pointer forward if XSDT pointer was already
non-zero, such as after warm reset. As a result, SSDT was written in
place of XSDT, which resulted in panic in edk2 after a reboot.

This change covers SSDT generation with the same check for existing
XSDT address as is used for tables generated by QEMU.

Change-Id: I7f38467b7de3f35fc3ec3854a840de8345cd0fe5
Signed-off-by: Krystian Hebel 
---
M src/acpi/acpi.c
1 file changed, 29 insertions(+), 29 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/98/82698/1

diff --git a/src/acpi/acpi.c b/src/acpi/acpi.c
index 39eadc3..61ce5d9 100644
--- a/src/acpi/acpi.c
+++ b/src/acpi/acpi.c
@@ -1506,37 +1506,37 @@
    		 */
    		for (int i = 0; existing_rsdt->entry[i]; i++)
    			acpi_add_table(rsdp, (void *)(uintptr_t)existing_rsdt->entry[i]);
+
+			/* Add BOOT0000 for Linux google firmware driver */
+			printk(BIOS_DEBUG, "ACPI:     * SSDT\n");
+			ssdt = (acpi_header_t *)current;
+			current += sizeof(acpi_header_t);
+
+			memset((void *)ssdt, 0, sizeof(acpi_header_t));
+
+			memcpy(&ssdt->signature, "SSDT", 4);
+			ssdt->revision = get_acpi_table_revision(SSDT);
+			memcpy(&ssdt->oem_id, OEM_ID, 6);
+			memcpy(&ssdt->oem_table_id, oem_table_id, 8);
+			ssdt->oem_revision = 42;
+			memcpy(&ssdt->asl_compiler_id, ASLC, 4);
+			ssdt->asl_compiler_revision = asl_revision;
+			ssdt->length = sizeof(acpi_header_t);
+
+			acpigen_set_current((char *)current);
+
+			/* Write object to declare coreboot tables */
+			acpi_ssdt_write_cbtable();
+
+			/* (Re)calculate length and checksum. */
+			ssdt->length = current - (unsigned long)ssdt;
+			ssdt->checksum = acpi_checksum((void *)ssdt, ssdt->length);
+
+			acpi_create_ssdt_generator(ssdt, NULL);
+
+			acpi_add_table(rsdp, ssdt);
    	}

-		/* Add BOOT0000 for Linux google firmware driver */
-		printk(BIOS_DEBUG, "ACPI:     * SSDT\n");
-		ssdt = (acpi_header_t *)current;
-		current += sizeof(acpi_header_t);
-
-		memset((void *)ssdt, 0, sizeof(acpi_header_t));
-
-		memcpy(&ssdt->signature, "SSDT", 4);
-		ssdt->revision = get_acpi_table_revision(SSDT);
-		memcpy(&ssdt->oem_id, OEM_ID, 6);
-		memcpy(&ssdt->oem_table_id, oem_table_id, 8);
-		ssdt->oem_revision = 42;
-		memcpy(&ssdt->asl_compiler_id, ASLC, 4);
-		ssdt->asl_compiler_revision = asl_revision;
-		ssdt->length = sizeof(acpi_header_t);
-
-		acpigen_set_current((char *)current);
-
-		/* Write object to declare coreboot tables */
-		acpi_ssdt_write_cbtable();
-
-		/* (Re)calculate length and checksum. */
-		ssdt->length = current - (unsigned long)ssdt;
-		ssdt->checksum = acpi_checksum((void *)ssdt, ssdt->length);
-
-		acpi_create_ssdt_generator(ssdt, NULL);
-
-		acpi_add_table(rsdp, ssdt);
-
    	return fw;
    }