From a299371a9ec109da3851cb43aed3e9157d095358 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Sun, 21 Feb 2010 14:32:34 -0800 Subject: [PATCH] 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: David Brownell --- src/target/arm_dpm.c | 151 ++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 113 insertions(+), 38 deletions(-) diff --git a/src/target/arm_dpm.c b/src/target/arm_dpm.c index 3c18e6334..0b5e25585 100644 --- a/src/target/arm_dpm.c +++ b/src/target/arm_dpm.c @@ -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); -- 2.11.4.GIT