stm32: Enter bootloader via a system reset.

Entering a bootloader (ST system bootloader, or custom mboot) from software
by directly branching to it is not reliable, and the reliability of it
working can depend on the peripherals that were enabled by the application
code.  It's also not possible to branch to a bootloader if the WDT is
enabled (unless the bootloader has specific provisions to feed the WDT).

This patch changes the way a bootloader is entered from software by first
doing a complete system reset, then branching to the desired bootloader
early on in the start-up process.  The top two words of RAM (of the stack)
are reserved to store flags indicating that the bootloader should be
entered after a reset.

21 files changed, 21 insertions, 21 deletions

diff --git a/ports/stm32/boards/PYBD_SF2/f722_qspi.ld b/ports/stm32/boards/PYBD_SF2/f722_qspi.ld
index e9d6fa3c3..b6d3e08e3 100644
--- a/ports/stm32/boards/PYBD_SF2/f722_qspi.ld
+++ b/ports/stm32/boards/PYBD_SF2/f722_qspi.ld
@@ -31,7 +31,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 16K;
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/PYBD_SF6/f767.ld b/ports/stm32/boards/PYBD_SF6/f767.ld
index 2a474fba0..1dd4c11ed 100644
--- a/ports/stm32/boards/PYBD_SF6/f767.ld
+++ b/ports/stm32/boards/PYBD_SF6/f767.ld
@@ -30,7 +30,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 24K;
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/STM32F769DISC/f769_qspi.ld b/ports/stm32/boards/STM32F769DISC/f769_qspi.ld
index 362fab330..9a0bd56fb 100644
--- a/ports/stm32/boards/STM32F769DISC/f769_qspi.ld
+++ b/ports/stm32/boards/STM32F769DISC/f769_qspi.ld
@@ -29,7 +29,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 32K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32f091xc.ld b/ports/stm32/boards/stm32f091xc.ld
index 5e1e9e7bd..5bcc4c727 100644
--- a/ports/stm32/boards/stm32f091xc.ld
+++ b/ports/stm32/boards/stm32f091xc.ld
@@ -16,7 +16,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 6K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32f401xd.ld b/ports/stm32/boards/stm32f401xd.ld
index 50cb3c571..f4146abc6 100644
--- a/ports/stm32/boards/stm32f401xd.ld
+++ b/ports/stm32/boards/stm32f401xd.ld
@@ -18,7 +18,7 @@ _minimum_heap_size = 16K; /* tunable */
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 16K;
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32f401xe.ld b/ports/stm32/boards/stm32f401xe.ld
index 78e0dc1cb..e7bd8edfe 100644
--- a/ports/stm32/boards/stm32f401xe.ld
+++ b/ports/stm32/boards/stm32f401xe.ld
@@ -18,7 +18,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 16K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32f405.ld b/ports/stm32/boards/stm32f405.ld
index 13133e8c6..b6f5d3057 100644
--- a/ports/stm32/boards/stm32f405.ld
+++ b/ports/stm32/boards/stm32f405.ld
@@ -19,7 +19,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 16K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32f411.ld b/ports/stm32/boards/stm32f411.ld
index 8ae5f6929..50633118e 100644
--- a/ports/stm32/boards/stm32f411.ld
+++ b/ports/stm32/boards/stm32f411.ld
@@ -18,7 +18,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 16K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32f413xg.ld b/ports/stm32/boards/stm32f413xg.ld
index c2719b834..96d6dc5fb 100644
--- a/ports/stm32/boards/stm32f413xg.ld
+++ b/ports/stm32/boards/stm32f413xg.ld
@@ -21,7 +21,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 16K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32f413xh.ld b/ports/stm32/boards/stm32f413xh.ld
index 017dbbac1..0b28730de 100644
--- a/ports/stm32/boards/stm32f413xh.ld
+++ b/ports/stm32/boards/stm32f413xh.ld
@@ -21,7 +21,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 16K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32f429.ld b/ports/stm32/boards/stm32f429.ld
index 35d0736ee..beeaa4df2 100644
--- a/ports/stm32/boards/stm32f429.ld
+++ b/ports/stm32/boards/stm32f429.ld
@@ -19,7 +19,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 16K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32f439.ld b/ports/stm32/boards/stm32f439.ld
index 2b51c3a37..e847646b3 100644
--- a/ports/stm32/boards/stm32f439.ld
+++ b/ports/stm32/boards/stm32f439.ld
@@ -20,7 +20,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 16K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32f722.ld b/ports/stm32/boards/stm32f722.ld
index 8986c68d5..ab41f0ea9 100644
--- a/ports/stm32/boards/stm32f722.ld
+++ b/ports/stm32/boards/stm32f722.ld
@@ -17,7 +17,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 32K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32f746.ld b/ports/stm32/boards/stm32f746.ld
index 330dd9714..0f1de2696 100644
--- a/ports/stm32/boards/stm32f746.ld
+++ b/ports/stm32/boards/stm32f746.ld
@@ -19,7 +19,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 16K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32f767.ld b/ports/stm32/boards/stm32f767.ld
index 47e992c2d..9410b9fa6 100644
--- a/ports/stm32/boards/stm32f767.ld
+++ b/ports/stm32/boards/stm32f767.ld
@@ -20,7 +20,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 32K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32f769.ld b/ports/stm32/boards/stm32f769.ld
index 41bb321a3..ebc6d033d 100644
--- a/ports/stm32/boards/stm32f769.ld
+++ b/ports/stm32/boards/stm32f769.ld
@@ -19,7 +19,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 32K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32h743.ld b/ports/stm32/boards/stm32h743.ld
index 0f1c2b777..69738ab8b 100644
--- a/ports/stm32/boards/stm32h743.ld
+++ b/ports/stm32/boards/stm32h743.ld
@@ -19,7 +19,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 16K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32l432.ld b/ports/stm32/boards/stm32l432.ld
index 40515e75b..5558b13c8 100644
--- a/ports/stm32/boards/stm32l432.ld
+++ b/ports/stm32/boards/stm32l432.ld
@@ -17,7 +17,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 6K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32l476xe.ld b/ports/stm32/boards/stm32l476xe.ld
index 330ec96e6..e4bcda1f1 100644
--- a/ports/stm32/boards/stm32l476xe.ld
+++ b/ports/stm32/boards/stm32l476xe.ld
@@ -20,7 +20,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 16K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32l476xg.ld b/ports/stm32/boards/stm32l476xg.ld
index 7983fb39a..9fe83c74a 100644
--- a/ports/stm32/boards/stm32l476xg.ld
+++ b/ports/stm32/boards/stm32l476xg.ld
@@ -20,7 +20,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM);
+_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
 _sstack = _estack - 16K; /* tunable */
 
 /* RAM extents for the garbage collector */
diff --git a/ports/stm32/boards/stm32l496xg.ld b/ports/stm32/boards/stm32l496xg.ld
index e1ceb5070..c33990342 100644
--- a/ports/stm32/boards/stm32l496xg.ld
+++ b/ports/stm32/boards/stm32l496xg.ld
@@ -20,7 +20,7 @@ _minimum_heap_size = 16K;
 
 /* Define the stack.  The stack is full descending so begins just above last byte
    of RAM.  Note that EABI requires the stack to be 8-byte aligned for a call. */
-_estack = ORIGIN(RAM) + LENGTH(RAM) + LENGTH(SRAM2);
+_estack = ORIGIN(RAM) + LENGTH(RAM) + LENGTH(SRAM2) - _estack_reserve;
 _sstack = _estack - 206K; /* tunable */
 
 /* RAM extents for the garbage collector */