From 1067d234359b0e14bf08d7c2087f74bc6ad30842 Mon Sep 17 00:00:00 2001
From: Rahix <rahix@rahix.de>
Date: Sat, 10 Aug 2019 18:19:38 +0200
Subject: [PATCH] fix(l0dables): Fix vector table alignment
The vector table's alignment requirements depend on the number of
interrupts [1]. In our case, we have 0x6E(=110) interrupts and thus an
alignment requirement of 0x80(=128).
To satisfy this requirement, this commit moves the IVT to the beginning
of .text and enforces a 128 byte alignment. Please note that the
headers which come before .text will push the IVT to 0x100 instead of
having it directly in the beginning at 0x00.
[1]: https://developer.arm.com/docs/dui0553/a/cortex-m4-peripherals/system-control-block/vector-table-offset-register
Signed-off-by: Rahix <rahix@rahix.de>
---
l0dables/lib/crt.s | 6 +++---
l0dables/lib/l0dable.ld | 3 +++
l0dables/lib/meson.build | 2 +-
3 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/l0dables/lib/crt.s b/l0dables/lib/crt.s
index b811c4e6c..57726cb56 100644
--- a/l0dables/lib/crt.s
+++ b/l0dables/lib/crt.s
@@ -18,10 +18,10 @@
*
* All of the following (apart from Reset_Handler, which calls main())
* are backed by weak referenced symbols, which you can override just
- * by defining them in C code.
+ * by defining them in C code.
*/
- .section .data
- .align 2
+ .section .text.isr_vector
+ .align 7
.globl __isr_vector
__isr_vector:
.long 0 /* Top of Stack, overriden by l0der at load time */
diff --git a/l0dables/lib/l0dable.ld b/l0dables/lib/l0dable.ld
index 31fbb773d..aa7225cfe 100644
--- a/l0dables/lib/l0dable.ld
+++ b/l0dables/lib/l0dable.ld
@@ -33,6 +33,9 @@ SECTIONS {
.text :
{
+ /* The vector table needs 128 byte alignment */
+ . = ALIGN(128);
+ KEEP(*(.text.isr_vector))
*(.text*)
*(.rodata*)
diff --git a/l0dables/lib/meson.build b/l0dables/lib/meson.build
index f2f16295a..d24075145 100644
--- a/l0dables/lib/meson.build
+++ b/l0dables/lib/meson.build
@@ -3,7 +3,7 @@ l0dable_startup_lib = static_library(
'crt.s',
'hardware.c',
dependencies: [api_caller],
- pic: true,
+ c_args: ['-fpie'],
)
l0dable_startup = declare_dependency(
--
GitLab