[edk2-devel] [PATCH v3 2/5] Platform/RaspberryPi: Monitor ACPI Table installs
Jeremy Linton
jeremy.linton at arm.com
Fri Aug 28 22:02:12 UTC 2020
Hook the ACPI table install sequence and add some
basic conditional and AML NameOp update logic. If
a table has a non-zero PCD declared that pcd is
checked for a non-zero value before allowing the table
to be installed. We also add a table of NameOp to
PCD's which will be written into a DSDT/SSDT table
as part of its install process.
With this change we can declare something in
ASL like:
Name (VARN, 0x1234)
and then add a table entry like:
{"VARN", PcdToken(PcdVarn)}
and the value of PcdVarn will replace the
0x1234 declared in the ASL above.
Cc: Leif Lindholm <leif at nuviainc.com>
Cc: Pete Batard <pete at akeo.ie>
Cc: Andrei Warkentin <awarkentin at vmware.com>
Cc: Ard Biesheuvel <ard.biesheuvel at arm.com>
Cc: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud at arm.com>
Signed-off-by: Jeremy Linton <jeremy.linton at arm.com>
---
Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c | 153 ++++++++++++++++++++-
1 file changed, 152 insertions(+), 1 deletion(-)
diff --git a/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c b/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c
index af54136ade..9e5d9734ca 100644
--- a/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c
+++ b/Platform/RaspberryPi/Drivers/ConfigDxe/ConfigDxe.c
@@ -568,6 +568,156 @@ ApplyVariables (
}
+typedef struct {
+ CHAR8 Name[4];
+ UINTN PcdToken;
+} AML_NAME_OP_REPLACE;
+
+typedef struct {
+ UINT64 OemTableId;
+ UINTN PcdToken;
+ AML_NAME_OP_REPLACE *SdtNameOpReplace;
+} NAMESPACE_TABLES;
+
+#define SSDT_PATTERN_LEN 5
+#define AML_NAMEOP_8 0x0A
+#define AML_NAMEOP_16 0x0B
+#define AML_NAMEOP_32 0x0C
+#define AML_NAMEOP_STR 0x0D
+/*
+ * Scan the given namespace table (DSDT/SSDT) for AML NameOps
+ * listed in the NameOpReplace structure. If one is found then
+ * update the value in the table from the specified Pcd
+ *
+ * This allows us to have conditionals in AML controlled
+ * by options in the BDS or detected during firmware bootstrap.
+ * We could extend this concept for strings/etc but due to len
+ * variations its probably easier to encode the strings
+ * in the ASL and pick the correct one based off a variable.
+ */
+STATIC VOID
+UpdateSdtNameOps(
+ EFI_ACPI_DESCRIPTION_HEADER *AcpiTable,
+ AML_NAME_OP_REPLACE *NameOpReplace
+ )
+{
+ UINTN Idx;
+ UINTN Index;
+ CHAR8 Pattern[SSDT_PATTERN_LEN];
+ UINTN PcdVal;
+ UINT8 *SdtPtr;
+ UINT32 SdtSize;
+
+ SdtSize = AcpiTable->Length;
+
+ if (SdtSize > 0) {
+ SdtPtr = (UINT8*)AcpiTable;
+
+ for (Idx = 0; NameOpReplace && NameOpReplace[Idx].PcdToken; Idx++) {
+ /*
+ * Do a single NameOp variable replacement these are of the
+ * form 08 XXXX SIZE VAL, where SIZE is 0A=byte, 0B=word, 0C=dword
+ * and XXXX is the name and VAL is the value
+ */
+ Pattern[0] = 0x08;
+ Pattern[1] = NameOpReplace[Idx].Name[0];
+ Pattern[2] = NameOpReplace[Idx].Name[1];
+ Pattern[3] = NameOpReplace[Idx].Name[2];
+ Pattern[4] = NameOpReplace[Idx].Name[3];
+
+ for (Index = 0; Index < (SdtSize - SSDT_PATTERN_LEN); Index++) {
+ if (CompareMem (SdtPtr + Index, Pattern, SSDT_PATTERN_LEN) == 0) {
+ PcdVal = LibPcdGet32 (NameOpReplace[Idx].PcdToken);
+ switch (SdtPtr[Index + SSDT_PATTERN_LEN]) {
+ case AML_NAMEOP_32:
+ SdtPtr[Index + SSDT_PATTERN_LEN + 4] = (PcdVal >> 24) & 0xFF;
+ SdtPtr[Index + SSDT_PATTERN_LEN + 3] = (PcdVal >> 16) & 0xFF;
+ // Fallthrough
+ case AML_NAMEOP_16:
+ SdtPtr[Index + SSDT_PATTERN_LEN + 2] = (PcdVal >> 8) & 0xFF;
+ // Fallthrough
+ case AML_NAMEOP_8:
+ SdtPtr[Index + SSDT_PATTERN_LEN + 1] = PcdVal & 0xFF;
+ break;
+ case 0:
+ case 1:
+ SdtPtr[Index + SSDT_PATTERN_LEN + 1] = !!PcdVal;
+ break;
+ case AML_NAMEOP_STR:
+ /*
+ * If the string val is added to the NameOpReplace, we can
+ * dynamically update things like _HID too as long as the
+ * string length matches.
+ */
+ break;
+ }
+ break;
+ }
+ }
+ }
+ }
+}
+
+
+STATIC BOOLEAN
+VerifyUpdateTable(
+ IN EFI_ACPI_DESCRIPTION_HEADER *AcpiHeader,
+ IN NAMESPACE_TABLES *SdtTable
+ )
+{
+ BOOLEAN ret;
+
+ ret = TRUE;
+ if (SdtTable->PcdToken && !LibPcdGet32 (SdtTable->PcdToken)) {
+ ret = FALSE;
+ }
+ if (ret && SdtTable->SdtNameOpReplace) {
+ UpdateSdtNameOps (AcpiHeader, SdtTable->SdtNameOpReplace);
+ }
+
+ return ret;
+}
+
+
+STATIC NAMESPACE_TABLES SdtTables[] = {
+ {
+ SIGNATURE_64 ('R', 'P', 'I', 0, 0, 0, 0, 0),
+ 0,
+ NULL
+ },
+ { }
+};
+
+/*
+ * Monitor the ACPI tables being installed and when
+ * a DSDT/SSDT is detected validate that we want to
+ * install it, and if so update any "NameOp" defined
+ * variables contained in the table from PCD values
+ */
+STATIC BOOLEAN
+HandleDynamicNamespace (
+ IN EFI_ACPI_DESCRIPTION_HEADER *AcpiHeader
+ )
+{
+ UINTN Tables;
+
+ switch (AcpiHeader->Signature) {
+ case SIGNATURE_32 ('D', 'S', 'D', 'T'):
+ case SIGNATURE_32 ('S', 'S', 'D', 'T'):
+ for (Tables = 0; SdtTables[Tables].OemTableId; Tables++) {
+ if (AcpiHeader->OemTableId == SdtTables[Tables].OemTableId) {
+ return VerifyUpdateTable (AcpiHeader, &SdtTables[Tables]);
+ }
+ }
+ DEBUG ((DEBUG_ERROR, "Found namespace table not in table list.\n"));
+
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+
EFI_STATUS
EFIAPI
ConfigInitialize (
@@ -618,7 +768,8 @@ ConfigInitialize (
if (PcdGet32 (PcdSystemTableMode) == SYSTEM_TABLE_MODE_ACPI ||
PcdGet32 (PcdSystemTableMode) == SYSTEM_TABLE_MODE_BOTH) {
- Status = LocateAndInstallAcpiFromFv (&mAcpiTableFile);
+ Status = LocateAndInstallAcpiFromFvConditional (&mAcpiTableFile,
+ &HandleDynamicNamespace);
ASSERT_EFI_ERROR (Status);
}
--
2.13.7
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