From 35691065f72110d4490df3a127467ea9c04c70ca Mon Sep 17 00:00:00 2001 From: Mike Dunn Date: Mon, 13 Sep 2010 12:45:37 -0700 Subject: [PATCH] xscale: fix sw breakpoints for thumb; set bp immediately MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi everyone, Version 2 of this patch. Code added to breakpoints.c was removed from previous patch, and item 3 added, per discussion with Øyvind regarding error reporting. Item 4 added, which I just noticed. I tried to use a software breakpoint in thumb code on the xscale for the first time recently, and was surprised to find that it didn't work. The result was this patch, which does four things: 1): fix trivial cut-n-paste error that caused thumb breakpoints to not work 2): call xscale_set_breakpoint() from xscale_add_breakpoint() 3): log error on data abort in xscale_write_memory() 4): fixed incorrect error code returned by xscale_set_breakpoint() when no breakpoint register is available; added comment Item 2 not only makes the xscale breakpoint code consistent with other targets, but also alerts the user immediately if an error occurs when writing the breakpoint instruction to target memory (previously, xscale_set_breakpoint() was not called until execution resumed). Also, calling xscale_breakpoint_set() as part of the call chain starting with handle_bp_command() and propagating the return status back up the chain avoids the situation where OpenOCD "thinks" the breakpoint is set when in reality an error ocurred. Item 3 provides a helpful message for a common reason for failure to set sw breakpoint. This was thoroughly tested, mindful of the fact that breakpoint management is somewhat dicey during single-stepping. Comments and criticisms of course gratefully received. Mike Signed-off-by: Mike Dunn Signed-off-by: Øyvind Harboe --- src/target/xscale.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/target/xscale.c b/src/target/xscale.c index 2b8bff16a..82b0f3427 100644 --- a/src/target/xscale.c +++ b/src/target/xscale.c @@ -1979,6 +1979,7 @@ static int xscale_write_memory(struct target *target, uint32_t address, if ((retval = xscale_send_u32(target, 0x60)) != ERROR_OK) return retval; + LOG_ERROR("data abort writing memory"); return ERROR_TARGET_DATA_ABORT; } @@ -2141,9 +2142,9 @@ static int xscale_set_breakpoint(struct target *target, breakpoint->set = 2; /* breakpoint set on second breakpoint register */ } else - { + { /* bug: availability previously verified in xscale_add_breakpoint() */ LOG_ERROR("BUG: no hardware comparator available"); - return ERROR_OK; + return ERROR_TARGET_RESOURCE_NOT_AVAILABLE; } } else if (breakpoint->type == BKPT_SOFT) @@ -2169,7 +2170,7 @@ static int xscale_set_breakpoint(struct target *target, return retval; } /* write the bkpt instruction in target endianness (arm7_9->arm_bkpt is host endian) */ - if ((retval = target_write_u32(target, breakpoint->address, xscale->thumb_bkpt)) != ERROR_OK) + if ((retval = target_write_u16(target, breakpoint->address, xscale->thumb_bkpt)) != ERROR_OK) { return retval; } @@ -2207,7 +2208,7 @@ static int xscale_add_breakpoint(struct target *target, xscale->ibcr_available--; } - return ERROR_OK; + return xscale_set_breakpoint(target, breakpoint); } static int xscale_unset_breakpoint(struct target *target,