ARM platforms: Add support for SEPARATE_CODE_AND_RODATA
The arm_setup_page_tables() function used to expect a single set of
addresses defining the extents of the whole read-only section, code
and read-only data mixed up, which was mapped as executable.
This patch changes this behaviour. arm_setup_page_tables() now
expects 2 separate sets of addresses:
- the extents of the code section;
- the extents of the read-only data section.
The code is mapped as executable, whereas the data is mapped as
execute-never. New #defines have been introduced to identify the
extents of the code and the read-only data section. Given that
all BL images except BL1 share the same memory layout and linker
script structure, these #defines are common across these images.
The slight memory layout differences in BL1 have been handled by
providing values specific to BL1.
Note that this patch also affects the Xilinx platform port, which
uses the arm_setup_page_tables() function. It has been updated
accordingly, such that the memory mappings on this platform are
unchanged. This is achieved by passing null values as the extents
of the read-only data section so that it is ignored. As a result,
the whole read-only section is still mapped as executable.
Fixes ARM-software/tf-issues#85
Change-Id: I1f95865c53ce6e253a01286ff56e0aa1161abac5
diff --git a/plat/arm/common/arm_bl2u_setup.c b/plat/arm/common/arm_bl2u_setup.c
index 8185f9f..de7d0c2 100644
--- a/plat/arm/common/arm_bl2u_setup.c
+++ b/plat/arm/common/arm_bl2u_setup.c
@@ -36,16 +36,6 @@
#include <plat_arm.h>
#include <string.h>
-
-/*
- * The next 2 constants identify the extents of the code & RO data region.
- * These addresses are used by the MMU setup code and therefore they must be
- * page-aligned. It is the responsibility of the linker script to ensure that
- * __RO_START__ and __RO_END__ linker symbols refer to page-aligned addresses.
- */
-#define BL2U_RO_BASE (unsigned long)(&__RO_START__)
-#define BL2U_RO_LIMIT (unsigned long)(&__RO_END__)
-
#if USE_COHERENT_MEM
/*
* The next 2 constants identify the extents of the coherent memory region.
@@ -104,8 +94,10 @@
{
arm_setup_page_tables(BL2U_BASE,
BL31_LIMIT,
- BL2U_RO_BASE,
- BL2U_RO_LIMIT
+ BL_CODE_BASE,
+ BL_CODE_LIMIT,
+ BL_RO_DATA_BASE,
+ BL_RO_DATA_LIMIT
#if USE_COHERENT_MEM
,
BL2U_COHERENT_RAM_BASE,