From 938ce22307194504431d91d162608c47e4b4ffd3 Mon Sep 17 00:00:00 2001
From: deadprogram <ron@hybridgroup.com>
Date: Fri, 27 Oct 2023 16:06:03 +0200
Subject: [PATCH] machine/stm32: implement DeviceID() with unique ID per
 processor

Signed-off-by: deadprogram <ron@hybridgroup.com>
---
 src/machine/machine_stm32.go     | 24 +++++++++++++++++++++++-
 src/machine/machine_stm32f103.go |  2 ++
 src/machine/machine_stm32f4.go   |  2 ++
 src/machine/machine_stm32f7.go   |  2 ++
 src/machine/machine_stm32l0.go   |  2 ++
 src/machine/machine_stm32l4.go   |  2 ++
 src/machine/machine_stm32l5.go   |  2 ++
 src/machine/machine_stm32wlx.go  |  2 ++
 8 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/src/machine/machine_stm32.go b/src/machine/machine_stm32.go
index 4f04cae4ce..1edaa2cd06 100644
--- a/src/machine/machine_stm32.go
+++ b/src/machine/machine_stm32.go
@@ -2,7 +2,12 @@
 
 package machine
 
-import "device/stm32"
+import (
+	"device/stm32"
+
+	"runtime/volatile"
+	"unsafe"
+)
 
 const deviceName = stm32.Device
 
@@ -80,3 +85,20 @@ func (p Pin) PortMaskClear() (*uint32, uint32) {
 	pin := uint8(p) % 16
 	return &port.BSRR.Reg, 1 << (pin + 16)
 }
+
+var deviceID [12]byte
+
+// DeviceID returns an identifier that is unique within
+// a particular chipset.
+//
+// The identity is one burnt into the MCU itself.
+//
+// The length of the device ID for STM32 is 12 bytes (96 bits).
+func DeviceID() []byte {
+	for i := 0; i < len(deviceID); i++ {
+		word := (*volatile.Register32)(unsafe.Pointer(deviceIDAddr[i/4])).Get()
+		deviceID[i] = byte(word >> ((i % 4) * 8))
+	}
+
+	return deviceID[:]
+}
diff --git a/src/machine/machine_stm32f103.go b/src/machine/machine_stm32f103.go
index e7593829bf..66a74d04b6 100644
--- a/src/machine/machine_stm32f103.go
+++ b/src/machine/machine_stm32f103.go
@@ -15,6 +15,8 @@ func CPUFrequency() uint32 {
 	return 72000000
 }
 
+var deviceIDAddr = []uintptr{0x1FFFF7E8, 0x1FFFF7EC, 0x1FFFF7F0}
+
 // Internal use: configured speed of the APB1 and APB2 timers, this should be kept
 // in sync with any changes to runtime package which configures the oscillators
 // and clock frequencies
diff --git a/src/machine/machine_stm32f4.go b/src/machine/machine_stm32f4.go
index 3b8923cb76..42193a7397 100644
--- a/src/machine/machine_stm32f4.go
+++ b/src/machine/machine_stm32f4.go
@@ -14,6 +14,8 @@ import (
 	"unsafe"
 )
 
+var deviceIDAddr = []uintptr{0x1FFF7A10, 0x1FFF7A14, 0x1FFF7A18}
+
 const (
 	PA0  = portA + 0
 	PA1  = portA + 1
diff --git a/src/machine/machine_stm32f7.go b/src/machine/machine_stm32f7.go
index a08d083a23..11eff11081 100644
--- a/src/machine/machine_stm32f7.go
+++ b/src/machine/machine_stm32f7.go
@@ -11,6 +11,8 @@ import (
 	"unsafe"
 )
 
+var deviceIDAddr = []uintptr{0x1FF0F420, 0x1FF0F424, 0x1FF0F428}
+
 // Alternative peripheral pin functions
 const (
 	AF0_SYSTEM                               = 0
diff --git a/src/machine/machine_stm32l0.go b/src/machine/machine_stm32l0.go
index f3d213c483..844cfccb49 100644
--- a/src/machine/machine_stm32l0.go
+++ b/src/machine/machine_stm32l0.go
@@ -13,6 +13,8 @@ func CPUFrequency() uint32 {
 	return 32000000
 }
 
+var deviceIDAddr = []uintptr{0x1FF80050, 0x1FF80054, 0x1FF80058}
+
 // Internal use: configured speed of the APB1 and APB2 timers, this should be kept
 // in sync with any changes to runtime package which configures the oscillators
 // and clock frequencies
diff --git a/src/machine/machine_stm32l4.go b/src/machine/machine_stm32l4.go
index f60a77e700..856320911b 100644
--- a/src/machine/machine_stm32l4.go
+++ b/src/machine/machine_stm32l4.go
@@ -13,6 +13,8 @@ import (
 
 // Peripheral abstraction layer for the stm32l4
 
+var deviceIDAddr = []uintptr{0x1FFF7590, 0x1FFF7594, 0x1FFF7598}
+
 const (
 	AF0_SYSTEM             = 0
 	AF1_TIM1_2_LPTIM1      = 1
diff --git a/src/machine/machine_stm32l5.go b/src/machine/machine_stm32l5.go
index d85157dbe9..faa583c9c3 100644
--- a/src/machine/machine_stm32l5.go
+++ b/src/machine/machine_stm32l5.go
@@ -11,6 +11,8 @@ import (
 	"unsafe"
 )
 
+var deviceIDAddr = []uintptr{0x0BFA0590, 0x0BFA0594, 0x0BFA0598}
+
 const (
 	AF0_SYSTEM                                = 0
 	AF1_TIM1_2_5_8_LPTIM1                     = 1
diff --git a/src/machine/machine_stm32wlx.go b/src/machine/machine_stm32wlx.go
index 010d038e03..d42ef2e383 100644
--- a/src/machine/machine_stm32wlx.go
+++ b/src/machine/machine_stm32wlx.go
@@ -14,6 +14,8 @@ import (
 	"unsafe"
 )
 
+var deviceIDAddr = []uintptr{0x1FFF7590, 0x1FFF7594, 0x1FFF7598}
+
 const (
 	AF0_SYSTEM             = 0
 	AF1_TIM1_2_LPTIM1      = 1