diff --git a/avr-specs/avr-atmega1280.json b/avr-specs/avr-atmega1280.json
index 8253bb1f6e..5fbc931f40 100644
--- a/avr-specs/avr-atmega1280.json
+++ b/avr-specs/avr-atmega1280.json
@@ -5,7 +5,6 @@
   "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
   "eh-frame-header": false,
   "exe-suffix": ".elf",
-  "executables": true,
   "late-link-args": {
     "gcc": [
       "-lgcc"
@@ -20,6 +19,7 @@
       "-mmcu=atmega1280"
     ]
   },
+  "relocation-model": "static",
   "target-c-int-width": "16",
   "target-pointer-width": "16"
 }
diff --git a/avr-specs/avr-atmega1284p.json b/avr-specs/avr-atmega1284p.json
index d3c8d98653..ee14275f29 100644
--- a/avr-specs/avr-atmega1284p.json
+++ b/avr-specs/avr-atmega1284p.json
@@ -5,7 +5,6 @@
   "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
   "eh-frame-header": false,
   "exe-suffix": ".elf",
-  "executables": true,
   "late-link-args": {
     "gcc": [
       "-lgcc"
@@ -20,6 +19,7 @@
       "-mmcu=atmega1284p"
     ]
   },
+  "relocation-model": "static",
   "target-c-int-width": "16",
   "target-pointer-width": "16"
 }
diff --git a/avr-specs/avr-atmega128a.json b/avr-specs/avr-atmega128a.json
index a206dada23..50a57bb539 100644
--- a/avr-specs/avr-atmega128a.json
+++ b/avr-specs/avr-atmega128a.json
@@ -1,31 +1,25 @@
 {
   "arch": "avr",
+  "atomic-cas": false,
   "cpu": "atmega128a",
   "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
-  "env": "",
-  "executables": true,
-  "linker": "avr-gcc",
-  "linker-flavor": "gcc",
-  "linker-is-gnu": true,
-  "llvm-target": "avr-unknown-unknown",
-  "os": "unknown",
-  "position-independent-executables": false,
-  "exe-suffix": ".elf",
   "eh-frame-header": false,
-  "pre-link-args": {
+  "exe-suffix": ".elf",
+  "late-link-args": {
     "gcc": [
-      "-Os",
-      "-mmcu=atmega128a"
+      "-lgcc"
     ]
   },
-  "late-link-args": {
+  "linker": "avr-gcc",
+  "llvm-target": "avr-unknown-unknown",
+  "max-atomic-width": 8,
+  "no-default-libraries": false,
+  "pre-link-args": {
     "gcc": [
-      "-lc",
-      "-lgcc"
+      "-mmcu=atmega128a"
     ]
   },
+  "relocation-model": "static",
   "target-c-int-width": "16",
-  "target-endian": "little",
-  "target-pointer-width": "16",
-  "vendor": "unknown"
+  "target-pointer-width": "16"
 }
diff --git a/avr-specs/avr-atmega168.json b/avr-specs/avr-atmega168.json
index c6fbfeca54..baac32ae20 100644
--- a/avr-specs/avr-atmega168.json
+++ b/avr-specs/avr-atmega168.json
@@ -5,7 +5,6 @@
   "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
   "eh-frame-header": false,
   "exe-suffix": ".elf",
-  "executables": true,
   "late-link-args": {
     "gcc": [
       "-lgcc"
@@ -20,6 +19,7 @@
       "-mmcu=atmega168"
     ]
   },
+  "relocation-model": "static",
   "target-c-int-width": "16",
   "target-pointer-width": "16"
 }
diff --git a/avr-specs/avr-atmega2560.json b/avr-specs/avr-atmega2560.json
index 6fcefb25c6..5d33bfe118 100644
--- a/avr-specs/avr-atmega2560.json
+++ b/avr-specs/avr-atmega2560.json
@@ -5,7 +5,6 @@
   "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
   "eh-frame-header": false,
   "exe-suffix": ".elf",
-  "executables": true,
   "late-link-args": {
     "gcc": [
       "-lgcc"
@@ -20,6 +19,7 @@
       "-mmcu=atmega2560"
     ]
   },
+  "relocation-model": "static",
   "target-c-int-width": "16",
   "target-pointer-width": "16"
 }
diff --git a/avr-specs/avr-atmega328p.json b/avr-specs/avr-atmega328p.json
index ab3dcdfa5f..7d7d82cc50 100644
--- a/avr-specs/avr-atmega328p.json
+++ b/avr-specs/avr-atmega328p.json
@@ -5,7 +5,6 @@
   "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
   "eh-frame-header": false,
   "exe-suffix": ".elf",
-  "executables": true,
   "late-link-args": {
     "gcc": [
       "-lgcc"
@@ -20,6 +19,7 @@
       "-mmcu=atmega328p"
     ]
   },
+  "relocation-model": "static",
   "target-c-int-width": "16",
   "target-pointer-width": "16"
 }
diff --git a/avr-specs/avr-atmega32u4.json b/avr-specs/avr-atmega32u4.json
index 637dbe5809..f078d2ebf5 100644
--- a/avr-specs/avr-atmega32u4.json
+++ b/avr-specs/avr-atmega32u4.json
@@ -5,7 +5,6 @@
   "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
   "eh-frame-header": false,
   "exe-suffix": ".elf",
-  "executables": true,
   "late-link-args": {
     "gcc": [
       "-lgcc"
@@ -20,6 +19,7 @@
       "-mmcu=atmega32u4"
     ]
   },
+  "relocation-model": "static",
   "target-c-int-width": "16",
   "target-pointer-width": "16"
 }
diff --git a/avr-specs/avr-atmega48p.json b/avr-specs/avr-atmega48p.json
index 0a2254ee4b..b13938d2eb 100644
--- a/avr-specs/avr-atmega48p.json
+++ b/avr-specs/avr-atmega48p.json
@@ -5,7 +5,6 @@
   "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
   "eh-frame-header": false,
   "exe-suffix": ".elf",
-  "executables": true,
   "late-link-args": {
     "gcc": [
       "-lgcc"
@@ -20,6 +19,7 @@
       "-mmcu=atmega48p"
     ]
   },
+  "relocation-model": "static",
   "target-c-int-width": "16",
   "target-pointer-width": "16"
 }
diff --git a/avr-specs/avr-atmega8.json b/avr-specs/avr-atmega8.json
index 10d5ddeae0..a7be935873 100644
--- a/avr-specs/avr-atmega8.json
+++ b/avr-specs/avr-atmega8.json
@@ -1,31 +1,25 @@
 {
   "arch": "avr",
+  "atomic-cas": false,
   "cpu": "atmega8",
   "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
-  "env": "",
-  "executables": true,
-  "linker": "avr-gcc",
-  "linker-flavor": "gcc",
-  "linker-is-gnu": true,
-  "llvm-target": "avr-unknown-unknown",
-  "os": "unknown",
-  "position-independent-executables": false,
-  "exe-suffix": ".elf",
   "eh-frame-header": false,
-  "pre-link-args": {
+  "exe-suffix": ".elf",
+  "late-link-args": {
     "gcc": [
-      "-Os",
-      "-mmcu=atmega8"
+      "-lgcc"
     ]
   },
-  "late-link-args": {
+  "linker": "avr-gcc",
+  "llvm-target": "avr-unknown-unknown",
+  "max-atomic-width": 8,
+  "no-default-libraries": false,
+  "pre-link-args": {
     "gcc": [
-      "-lc",
-      "-lgcc"
+      "-mmcu=atmega8"
     ]
   },
+  "relocation-model": "static",
   "target-c-int-width": "16",
-  "target-endian": "little",
-  "target-pointer-width": "16",
-  "vendor": "unknown"
+  "target-pointer-width": "16"
 }
diff --git a/avr-specs/avr-attiny167.json b/avr-specs/avr-attiny167.json
index dcc40f1239..962df8af71 100644
--- a/avr-specs/avr-attiny167.json
+++ b/avr-specs/avr-attiny167.json
@@ -5,7 +5,6 @@
   "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
   "eh-frame-header": false,
   "exe-suffix": ".elf",
-  "executables": true,
   "late-link-args": {
     "gcc": [
       "-lgcc"
@@ -20,6 +19,7 @@
       "-mmcu=attiny167"
     ]
   },
+  "relocation-model": "static",
   "target-c-int-width": "16",
   "target-pointer-width": "16"
 }
diff --git a/avr-specs/avr-attiny2313.json b/avr-specs/avr-attiny2313.json
index b833d8b68c..a5599e5362 100644
--- a/avr-specs/avr-attiny2313.json
+++ b/avr-specs/avr-attiny2313.json
@@ -5,7 +5,6 @@
   "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
   "eh-frame-header": false,
   "exe-suffix": ".elf",
-  "executables": true,
   "late-link-args": {
     "gcc": [
       "-lgcc"
@@ -20,6 +19,7 @@
       "-mmcu=attiny2313"
     ]
   },
+  "relocation-model": "static",
   "target-c-int-width": "16",
   "target-pointer-width": "16"
 }
diff --git a/avr-specs/avr-attiny85.json b/avr-specs/avr-attiny85.json
index 5d092a1d8e..9d577dabed 100644
--- a/avr-specs/avr-attiny85.json
+++ b/avr-specs/avr-attiny85.json
@@ -5,7 +5,6 @@
   "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
   "eh-frame-header": false,
   "exe-suffix": ".elf",
-  "executables": true,
   "late-link-args": {
     "gcc": [
       "-lgcc"
@@ -20,6 +19,7 @@
       "-mmcu=attiny85"
     ]
   },
+  "relocation-model": "static",
   "target-c-int-width": "16",
   "target-pointer-width": "16"
 }
diff --git a/avr-specs/avr-attiny88.json b/avr-specs/avr-attiny88.json
index 0a330cdae5..5ab1e58f93 100644
--- a/avr-specs/avr-attiny88.json
+++ b/avr-specs/avr-attiny88.json
@@ -5,7 +5,6 @@
   "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
   "eh-frame-header": false,
   "exe-suffix": ".elf",
-  "executables": true,
   "late-link-args": {
     "gcc": [
       "-lgcc"
@@ -20,6 +19,7 @@
       "-mmcu=attiny88"
     ]
   },
+  "relocation-model": "static",
   "target-c-int-width": "16",
   "target-pointer-width": "16"
 }