auracaster/openocd
3
0
Fork 1
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

arm7_9: Avoid infinite loops in bulk write dispatching

Browse Source 
Add a mandatory field in struct arm7_9_common for regular, non-optimized
memory writes. Together with the existing bulk_memory_write field, this
allows variants to select any combination of implementations for regular
and bulk writes, without risking infinite loops from accidentally using
bulk writes for implementing bulk writes.

ARM 7/9 targets may now select arm7_9_memory_write_opt as their
target.write_memory implementation, which will dispatch to
arm7_9_common.bulk_write_memory if possible, or fallback to
arm7_9_common.write_memory otherwise.

To avoid loops, bulk write implementations mustn't call any other
functions than arm7_9_write_memory_no_opt() to write memory; it will
unconditionally call arm7_9_common.write_memory. If they fail, they should
simply return error to allow the caller to fallback to regular writes.

Tested on a regular ARM7TDMI only.

Change-Id: Iae42a6e093e2df68c4823c927d757ae8f42ef388
Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Reviewed-on: http://openocd.zylin.com/1685
Tested-by: jenkins
Reviewed-by: Sergey A. Borshch <sb-sf@users.sourceforge.net>
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>
This commit is contained in:
Andreas Fritiofson
2013-10-05 00:19:08 +02:00
committed by Spencer Oliver
parent 8e6e7948de
commit ff5ec942d8
10 changed files with 61 additions and 42 deletions
Download Patch File Download Diff File Expand all files Collapse all files

37
src/target/arm7_9_common.c
View File

@@ -2476,11 +2476,28 @@ int arm7_9_write_memory_opt(struct target *target,
const uint8_t *buffer)
{
struct arm7_9_common *arm7_9 = target_to_arm7_9(target);
int retval;
if (size == 4 && count > 32 && arm7_9->bulk_write_memory)
return arm7_9->bulk_write_memory(target, address, count, buffer);
else
return arm7_9_write_memory(target, address, size, count, buffer);
if (size == 4 && count > 32 && arm7_9->bulk_write_memory) {
/* Attempt to do a bulk write */
retval = arm7_9->bulk_write_memory(target, address, count, buffer);
if (retval == ERROR_OK)
return ERROR_OK;
}
return arm7_9->write_memory(target, address, size, count, buffer);
}
int arm7_9_write_memory_no_opt(struct target *target,
uint32_t address,
uint32_t size,
uint32_t count,
const uint8_t *buffer)
{
struct arm7_9_common *arm7_9 = target_to_arm7_9(target);
return arm7_9->write_memory(target, address, size, count, buffer);
}
static int dcc_count;
@@ -2561,8 +2578,11 @@ int arm7_9_bulk_write_memory(struct target *target,
struct arm7_9_common *arm7_9 = target_to_arm7_9(target);
int i;
if (address % 4 != 0)
return ERROR_TARGET_UNALIGNED_ACCESS;
if (!arm7_9->dcc_downloads)
return target_write_memory(target, address, 4, count, buffer);
return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
/* regrab previously allocated working_area, or allocate a new one */
if (!arm7_9->dcc_working_area) {
@@ -2571,15 +2591,16 @@ int arm7_9_bulk_write_memory(struct target *target,
/* make sure we have a working area */
if (target_alloc_working_area(target, 24, &arm7_9->dcc_working_area) != ERROR_OK) {
LOG_INFO("no working area available, falling back to memory writes");
return target_write_memory(target, address, 4, count, buffer);
return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
}
/* copy target instructions to target endianness */
for (i = 0; i < 6; i++)
target_buffer_set_u32(target, dcc_code_buf + i*4, dcc_code[i]);
/* write DCC code to working area */
retval = target_write_memory(target,
/* write DCC code to working area, using the non-optimized
* memory write to avoid ending up here again */
retval = arm7_9_write_memory_no_opt(target,
arm7_9->dcc_working_area->address, 4, 6, dcc_code_buf);
if (retval != ERROR_OK)
return retval;