On 3 December 2015 at 00:18, Michael Davidsaver <[email protected]> wrote:
> Implement Configuration and Control register.
> Handle STACKALIGN and USERSETMPEND bits.
The patch doesn't seem to do anything with USERSETMPEND,
though it does do something with NONBASETHRDENA.
> ---
> hw/intc/armv7m_nvic.c | 15 +++++++++++----
> target-arm/cpu.h | 1 +
> target-arm/helper.c | 8 +++-----
> target-arm/machine.c | 1 +
> 4 files changed, 16 insertions(+), 9 deletions(-)
>
> diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c
> index 7d261ae..0f9ca6a 100644
> --- a/hw/intc/armv7m_nvic.c
> +++ b/hw/intc/armv7m_nvic.c
> @@ -534,8 +534,7 @@ static uint32_t nvic_readl(NVICState *s, uint32_t offset)
> /* TODO: Implement SLEEPONEXIT. */
> return 0;
> case 0xd14: /* Configuration Control. */
> - /* TODO: Implement Configuration Control bits. */
> - return 0;
> + return cpu->env.v7m.ccr;
> case 0xd24: /* System Handler Status. */
> val = 0;
> if (s->vectors[ARMV7M_EXCP_MEM].active) val |= (1 << 0);
> @@ -685,9 +684,17 @@ static void nvic_writel(NVICState *s, uint32_t offset,
> uint32_t value)
> }
> break;
> case 0xd10: /* System Control. */
> - case 0xd14: /* Configuration Control. */
> /* TODO: Implement control registers. */
> - qemu_log_mask(LOG_UNIMP, "NVIC: SCR and CCR unimplemented\n");
> + qemu_log_mask(LOG_UNIMP, "NVIC: SCR unimplemented\n");
> + break;
> + case 0xd14: /* Configuration Control. */
> + value &= 0x31b;
> + if (value & 0x118) {
> + qemu_log_mask(LOG_UNIMP, "CCR unimplemented bits"
> + " BFHFNMIGN, DIV_0_TRP, UNALIGN_TRP");
> + value &= ~0x118;
There's not much point in clearing out the bits we don't implement;
we may as well let them read-as-written.
> + }
> + cpu->env.v7m.ccr = value;
> break;
> case 0xd24: /* System Handler Control. */
> /* TODO: Real hardware allows you to set/clear the active bits
> diff --git a/target-arm/cpu.h b/target-arm/cpu.h
> index b98ef89..4e1b8cf 100644
> --- a/target-arm/cpu.h
> +++ b/target-arm/cpu.h
> @@ -396,6 +396,7 @@ typedef struct CPUARMState {
> uint32_t vecbase;
> uint32_t basepri;
> uint32_t control;
> + uint32_t ccr; /* Configuration and Control */
> uint32_t cfsr; /* Configurable Fault Status */
> uint32_t hfsr; /* HardFault Status */
> uint32_t mmfar; /* MemManage Fault Address */
> diff --git a/target-arm/helper.c b/target-arm/helper.c
> index f7e496d..17d1ca0 100644
> --- a/target-arm/helper.c
> +++ b/target-arm/helper.c
> @@ -5412,7 +5412,7 @@ static void do_v7m_exception_exit(CPUARMState *env)
> break;
> case 0x9: /* Return to Thread mode w/ Main stack */
> case 0xd: /* Return to Thread mode w/ Process stack */
> - if (env->v7m.exception_prio != 0x100) {
> + if ((env->v7m.exception_prio != 0x100) && !(env->v7m.ccr & 1)) {
A #define for CCR_NONBASETHRDENA would be nice (and for
CCR_STKALIGN).
> /* Attempt to return to Thread mode
> * from nested handler while NONBASETHRDENA not set.
> */
> @@ -5582,10 +5582,8 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs)
>
> qemu_log_mask(CPU_LOG_INT, "... as %d\n", env->v7m.exception);
>
> - /* Align stack pointer. */
> - /* ??? Should only do this if Configuration Control Register
> - STACKALIGN bit is set. */
> - if (env->regs[13] & 4) {
> + /* Align stack pointer (STACKALIGN) */
> + if ((env->regs[13] & 4) && (env->v7m.ccr & (1<<9))) {
Spaces around operators.
> env->regs[13] -= 4;
> xpsr |= 0x200;
> }
> diff --git a/target-arm/machine.c b/target-arm/machine.c
> index 14a4882..7aee41e 100644
> --- a/target-arm/machine.c
> +++ b/target-arm/machine.c
> @@ -100,6 +100,7 @@ static const VMStateDescription vmstate_m = {
> VMSTATE_UINT32(env.v7m.vecbase, ARMCPU),
> VMSTATE_UINT32(env.v7m.basepri, ARMCPU),
> VMSTATE_UINT32(env.v7m.control, ARMCPU),
> + VMSTATE_UINT32(env.v7m.ccr, ARMCPU),
> VMSTATE_UINT32(env.v7m.cfsr, ARMCPU),
> VMSTATE_UINT32(env.v7m.hfsr, ARMCPU),
> VMSTATE_UINT32(env.v7m.mmfar, ARMCPU),
Changing the vmstate implies that we should be bumping its
version number.
thanks
-- PMM
