Merge c5d061949c into 5bed97dd57

This change adds a new efi firmware type device entry for the .hwids section.
It also adds compile time validations for them.

Since currently there is only one device type (devicetree), chid_match()
compares the descriptor value of this device type directly and errors out for
other descriptors. Fix chid_match() to support the new device type.

While at it, add _DEVICE_TYPE_MAX to indicate maximum types of devices that
are supported currently.

src/boot/chid.c

@@ -22,9 +22,12 @@
 #include "util.h"
 
 /* Validate the descriptor macros a bit that they match our expectations */
-assert_cc(DEVICE_DESCRIPTOR_DEVICETREE == UINT32_C(0x1000001C));
+assert_cc(DEVICE_DESCRIPTOR_DEVICETREE == UINT32_C(0x10000020));
+assert_cc(DEVICE_DESCRIPTOR_EFIFW == UINT32_C(0x20000020));
 assert_cc(DEVICE_SIZE_FROM_DESCRIPTOR(DEVICE_DESCRIPTOR_DEVICETREE) == sizeof(Device));
 assert_cc(DEVICE_TYPE_FROM_DESCRIPTOR(DEVICE_DESCRIPTOR_DEVICETREE) == DEVICE_TYPE_DEVICETREE);
+assert_cc(DEVICE_SIZE_FROM_DESCRIPTOR(DEVICE_DESCRIPTOR_EFIFW) == sizeof(Device));
+assert_cc(DEVICE_TYPE_FROM_DESCRIPTOR(DEVICE_DESCRIPTOR_EFIFW) == DEVICE_TYPE_EFIFW);
 
 /**
  * smbios_to_hashable_string() - Convert ascii smbios string to stripped char16_t.
@@ -107,13 +110,15 @@ EFI_STATUS chid_match(const void *hwid_buffer, size_t hwid_length, const Device
                 return log_error_status(status, "Failed to populate board CHIDs: %m");
 
         size_t n_devices = 0;
+        uint32_t dev_type;
 
         /* Count devices and check validity */
         for (; (n_devices + 1) * sizeof(*devices) < hwid_length;) {
 
+                dev_type = DEVICE_TYPE_FROM_DESCRIPTOR(devices[n_devices].descriptor);
                 if (devices[n_devices].descriptor == DEVICE_DESCRIPTOR_EOL)
                         break;
-                if (devices[n_devices].descriptor != DEVICE_DESCRIPTOR_DEVICETREE)
+                if ((dev_type != DEVICE_TYPE_EFIFW) && (dev_type != DEVICE_TYPE_DEVICETREE))
                         return EFI_UNSUPPORTED;
                 n_devices++;
         }

src/boot/chid.h

@@ -11,11 +11,13 @@
 
 enum {
         DEVICE_TYPE_DEVICETREE = 0x1, /* A devicetree blob */
+        DEVICE_TYPE_EFIFW, /* an efi firmware blob */
 
         /* Maybe later additional types for:
          *   - CoCo Bring-Your-Own-Firmware
          *   - ACPI DSDT Overrides
          *   - … */
+        _DEVICE_TYPE_MAX,
 };
 
 #define DEVICE_SIZE_FROM_DESCRIPTOR(u) ((uint32_t) (u) & UINT32_C(0x0FFFFFFF))
@@ -23,6 +25,7 @@ enum {
 #define DEVICE_MAKE_DESCRIPTOR(type, size) (((uint32_t) (size) | ((uint32_t) type << 28)))
 
 #define DEVICE_DESCRIPTOR_DEVICETREE DEVICE_MAKE_DESCRIPTOR(DEVICE_TYPE_DEVICETREE, sizeof(Device))
+#define DEVICE_DESCRIPTOR_EFIFW DEVICE_MAKE_DESCRIPTOR(DEVICE_TYPE_EFIFW, sizeof(Device))
 #define DEVICE_DESCRIPTOR_EOL UINT32_C(0)
 
 typedef struct Device {
@@ -36,6 +39,14 @@ typedef struct Device {
                         uint32_t name_offset;          /* nul-terminated string or 0 if not present */
                         uint32_t compatible_offset;    /* nul-terminated string or 0 if not present */
                 } devicetree;
+                struct {
+                        /* Offsets are relative to the beginning of the .hwids PE section.
+                           They are nul-terminated strings when present or 0 if not present */
+                        uint32_t id_offset;         /* identifier for the firmware blob */
+                        uint32_t metadata_offset;   /* firmware metadata string */
+                        uint32_t compatible_offset; /* compatibility identifier to match a specific fw blob */
+                } efifw;
+
                 /* fields for other descriptor types… */
         };
 } _packed_ Device;
@@ -45,16 +56,19 @@ assert_cc(offsetof(Device, descriptor) == 0);
 assert_cc(offsetof(Device, chid) == 4);
 assert_cc(offsetof(Device, devicetree.name_offset) == 20);
 assert_cc(offsetof(Device, devicetree.compatible_offset) == 24);
-assert_cc(sizeof(Device) == 28);
+assert_cc(offsetof(Device, efifw.id_offset) == 20);
+assert_cc(offsetof(Device, efifw.metadata_offset) == 24);
+assert_cc(offsetof(Device, efifw.compatible_offset) == 28);
+assert_cc(sizeof(Device) == 32);
 
-static inline const char* device_get_name(const void *base, const Device *device) {
+static inline const char* device_get_devicetree_name(const void *base, const Device *device) {
         if (device->descriptor != DEVICE_DESCRIPTOR_DEVICETREE)
                 return NULL;
 
         return device->devicetree.name_offset == 0 ? NULL : (const char *) ((const uint8_t *) base + device->devicetree.name_offset);
 }
 
-static inline const char* device_get_compatible(const void *base, const Device *device) {
+static inline const char* device_get_devicetree_compatible(const void *base, const Device *device) {
         if (device->descriptor != DEVICE_DESCRIPTOR_DEVICETREE)
                 return NULL;
 

src/boot/pe.c

@@ -185,7 +185,7 @@ static bool pe_use_this_dtb(
         if (!device || !base)
                 return false;
 
-        const char *compatible = device_get_compatible(base, device);
+        const char *compatible = device_get_devicetree_compatible(base, device);
         if (!compatible)
                 return false;