From 7717d7b6e24b4d361ca7c5e7ef12f056e898e357 Mon Sep 17 00:00:00 2001
From: Per <Per Lindgren>
Date: Tue, 28 Feb 2017 11:11:08 +0000
Subject: [PATCH] doc
---
README.md | 15 ++++++++++-----
include/SRP.h | 2 +-
2 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/README.md b/README.md
index 1943ef2..ea7b61a 100644
--- a/README.md
+++ b/README.md
@@ -54,10 +54,11 @@ For further info on gdb debugging in eclipse see e.g., http://gnuarmeclipse.gith
The trace_printf is redirected to the ITM port, and you should get a trace of your program in the terminal.
Notice, that setting breakpoints in the code may be a bit wonky, we use macros and that confuses the eclipse gdb interface.
-The `BREAKPOINT` macro infers a compiler barrier that "should" allow you to put breakpoints in the code. Stepping in code that
-is creating interrupts is also wonky, e.g., if sigle stepping over a `JOB_REQUEST` (that "pends" the corresponding interrupt handler),
-the pend bit is correctly handeled. This is not a problem for this project only, but a general problem of the gdb integration, so
-be aware.
+The `BREAKPOINT` macro infers a compiler barrier that "should" allow you to break at those
+(there are two such `BREAKPOINT`s in the exampe, try put a breakpoint on those to see how it works) . Stepping in code that
+causes interrupts is also wonky, e.g., when sigle stepping over a `JOB_REQUEST` (that "pends" the corresponding interrupt handler),
+the pend bit is not correctly handeled (and the corresponding interrupt not taken). These problems are present for this project only,
+but general to the gdb debug integration, so be aware.
## Problems
@@ -66,7 +67,11 @@ ordinary file but rather a (linux/posix) FIFO, allowing the openocd to pipe data
and restart it, and try to launch the debugger again.
## Tips
-
+If you want, you can inspect the `BASEPRI` register (you find it under Registers) to see the system ceiling, but be aware that the priority is the hardware prio, shifted.
+(See how we use the `__set_BASEPRI_MAX` in the `LOCK` macro.)
+The current running priority is a bit harder to see, however you see the call stack (in the Debug window, and we know the prio
+for each task/job/interrupt handler). Notice, the call stack shows the name of the handlers, but we have defined
+the mapping, so its easy to reverse, right!
diff --git a/include/SRP.h b/include/SRP.h
index 54ea8bd..09741d4 100644
--- a/include/SRP.h
+++ b/include/SRP.h
@@ -12,7 +12,7 @@
#define Ceiling(R) (R##_Ceiling)
#define Code(J) (J##_Code)
#define IRQn(J) (J##_IRQn)
-#define H(X) (16-X)
+#define H(X) ((1 << __NVIC_PRIO_BITS)-X)
#define IRQh(J) (J##_IRQh)
#define BARRIER_LOCK { asm volatile("dsb\n" "isb\n" ::: "memory"); }
--
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