Commit a299371a authored by David Brownell's avatar David Brownell
Browse files

ARM DPM: support adding/removing HW breakpoints



Generalize the core of watchpoint setup so that it can handle
breakpoints too.  Create breakpoint add/remove routines which
will use that, and hook them up to target types which don't
provide their own breakpoint support (nothing, yet).

This suffices for hardware-only breakpoint support.  The ARM11
code will be able to switch over to this without much trouble,
since it doesn't yet handle software breakpoints.  Switching
Cortex-A8 will be a bit more involved.

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
parent 27c068c1
......@@ -320,14 +320,17 @@ static int dpm_maybe_update_bpwp(struct arm_dpm *dpm, bool bpwp,
xp->address, xp->control);
if (retval != ERROR_OK)
LOG_ERROR("%s: can't %s HW bp/wp %d",
LOG_ERROR("%s: can't %s HW %spoint %d",
disable ? "disable" : "enable",
target_name(dpm->arm->target),
xp->number);
(xp->number < 16) ? "break" : "watch",
xp->number & 0xf);
done:
return retval;
}
static int dpm_add_breakpoint(struct target *target, struct breakpoint *bp);
/**
* Writes all modified core registers for all processor modes. In normal
* operation this is called on exit from halting debug state.
......@@ -354,7 +357,7 @@ int arm_dpm_write_dirty_registers(struct arm_dpm *dpm, bool bpwp)
* we should be able to assume we handle them; but until then,
* cope with the hand-crafted breakpoint code.
*/
if (0) {
if (arm->target->type->add_breakpoint == dpm_add_breakpoint) {
for (unsigned i = 0; i < dpm->nbp; i++) {
struct dpm_bp *dbp = dpm->dbp + i;
struct breakpoint *bp = dbp->bp;
......@@ -665,43 +668,26 @@ done:
* fact isn't currently leveraged.
*/
static int dpm_watchpoint_setup(struct arm_dpm *dpm, unsigned index,
struct watchpoint *wp)
static int dpm_bpwp_setup(struct arm_dpm *dpm, struct dpm_bpwp *xp,
uint32_t addr, uint32_t length)
{
uint32_t addr = wp->address;
uint32_t control;
/* this hardware doesn't support data value matching or masking */
if (wp->value || wp->mask != ~(uint32_t)0) {
LOG_DEBUG("watchpoint values and masking not supported");
return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
}
control = (1 << 0) /* enable */
| (3 << 1); /* both user and privileged access */
switch (wp->rw) {
case WPT_READ:
control |= 1 << 3;
break;
case WPT_WRITE:
control |= 2 << 3;
break;
case WPT_ACCESS:
control |= 3 << 3;
break;
}
/* Match 1, 2, or all 4 byte addresses in this word.
*
* FIXME: v7 hardware allows lengths up to 2 GB, and has eight
* byte address select bits. Support larger wp->length, if addr
* is suitably aligned.
* FIXME: v7 hardware allows lengths up to 2 GB for BP and WP.
* Support larger length, when addr is suitably aligned. In
* particular, allow watchpoints on 8 byte "double" values.
*
* REVISIT allow watchpoints on unaligned 2-bit values; and on
* v7 hardware, unaligned 4-byte ones too.
*/
switch (wp->length) {
switch (length) {
case 1:
control |= (1 << (addr & 3)) << 5;
addr &= ~3;
break;
case 2:
/* require 2-byte alignment */
......@@ -718,26 +704,110 @@ static int dpm_watchpoint_setup(struct arm_dpm *dpm, unsigned index,
}
/* FALL THROUGH */
default:
LOG_DEBUG("bad watchpoint length or alignment");
LOG_ERROR("unsupported {break,watch}point length/alignment");
return ERROR_INVALID_ARGUMENTS;
}
/* other control bits:
* bits 9:12 == 0 ... only checking up to four byte addresses (v7 only)
/* other shared control bits:
* bits 15:14 == 0 ... both secure and nonsecure states (v6.1+ only)
* bit 20 == 0 ... not linked to a context ID
* bit 28:24 == 0 ... not ignoring N LSBs (v7 only)
*/
dpm->dwp[index].wp = wp;
dpm->dwp[index].bpwp.address = addr & ~3;
dpm->dwp[index].bpwp.control = control;
dpm->dwp[index].bpwp.dirty = true;
xp->address = addr & ~3;
xp->control = control;
xp->dirty = true;
LOG_DEBUG("BPWP: addr %8.8x, control %x, number %d",
xp->address, control, xp->number);
/* hardware is updated in write_dirty_registers() */
return ERROR_OK;
}
static int dpm_add_breakpoint(struct target *target, struct breakpoint *bp)
{
struct arm *arm = target_to_arm(target);
struct arm_dpm *dpm = arm->dpm;
int retval = ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
if (bp->length < 2)
return ERROR_INVALID_ARGUMENTS;
if (!dpm->bpwp_enable)
return retval;
/* FIXME we need a generic solution for software breakpoints. */
if (bp->type == BKPT_SOFT)
LOG_DEBUG("using HW bkpt, not SW...");
for (unsigned i = 0; i < dpm->nbp; i++) {
if (!dpm->dbp[i].bp) {
retval = dpm_bpwp_setup(dpm, &dpm->dbp[i].bpwp,
bp->address, bp->length);
if (retval == ERROR_OK)
dpm->dbp[i].bp = bp;
break;
}
}
return retval;
}
static int dpm_remove_breakpoint(struct target *target, struct breakpoint *bp)
{
struct arm *arm = target_to_arm(target);
struct arm_dpm *dpm = arm->dpm;
int retval = ERROR_INVALID_ARGUMENTS;
for (unsigned i = 0; i < dpm->nbp; i++) {
if (dpm->dbp[i].bp == bp) {
dpm->dbp[i].bp = NULL;
dpm->dbp[i].bpwp.dirty = true;
/* hardware is updated in write_dirty_registers() */
retval = ERROR_OK;
break;
}
}
return retval;
}
static int dpm_watchpoint_setup(struct arm_dpm *dpm, unsigned index,
struct watchpoint *wp)
{
int retval;
struct dpm_wp *dwp = dpm->dwp + index;
uint32_t control;
/* this hardware doesn't support data value matching or masking */
if (wp->value || wp->mask != ~(uint32_t)0) {
LOG_DEBUG("watchpoint values and masking not supported");
return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
}
retval = dpm_bpwp_setup(dpm, &dwp->bpwp, wp->address, wp->length);
if (retval != ERROR_OK)
return retval;
control = dwp->bpwp.control;
switch (wp->rw) {
case WPT_READ:
control |= 1 << 3;
break;
case WPT_WRITE:
control |= 2 << 3;
break;
case WPT_ACCESS:
control |= 3 << 3;
break;
}
dwp->bpwp.control = control;
dpm->dwp[index].wp = wp;
return retval;
}
static int dpm_add_watchpoint(struct target *target, struct watchpoint *wp)
{
......@@ -865,11 +935,16 @@ int arm_dpm_setup(struct arm_dpm *dpm)
arm->mrc = dpm_mrc;
arm->mcr = dpm_mcr;
/* breakpoint and watchpoint setup */
/* breakpoint setup -- optional until it works everywhere */
if (!target->type->add_breakpoint) {
target->type->add_breakpoint = dpm_add_breakpoint;
target->type->remove_breakpoint = dpm_remove_breakpoint;
}
/* watchpoint setup */
target->type->add_watchpoint = dpm_add_watchpoint;
target->type->remove_watchpoint = dpm_remove_watchpoint;
/* FIXME add breakpoint support */
/* FIXME add vector catch support */
dpm->nbp = 1 + ((dpm->didr >> 24) & 0xf);
......
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