qemu/include/hw/arm/armv7m.h
Peter Maydell 9e60d759d3 hw/intc/armv7m_nvic: Provide default "reset the system" behaviour for SYSRESETREQ
The NVIC provides an outbound qemu_irq "SYSRESETREQ" which it signals
when the guest sets the SYSRESETREQ bit in the AIRCR register.  This
matches the hardware design (where the CPU has a signal of this name
and it is up to the SoC to connect that up to an actual reset
mechanism), but in QEMU it mostly results in duplicated code in SoC
objects and bugs where SoC model implementors forget to wire up the
SYSRESETREQ line.

Provide a default behaviour for the case where SYSRESETREQ is not
actually connected to anything: use qemu_system_reset_request() to
perform a system reset.  This will allow us to remove the
implementations of SYSRESETREQ handling from the boards where that's
exactly what it does, and also fixes the bugs in the board models
which forgot to wire up the signal:

 * microbit
 * mps2-an385
 * mps2-an505
 * mps2-an511
 * mps2-an521
 * musca-a
 * musca-b1
 * netduino
 * netduinoplus2

We still allow the board to wire up the signal if it needs to, in case
we need to model more complicated reset controller logic or to model
buggy SoC hardware which forgot to wire up the line itself. But
defaulting to "reset the system" is more often going to be correct
than defaulting to "do nothing".

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20200728103744.6909-3-peter.maydell@linaro.org
2020-08-03 17:55:03 +01:00

78 lines
2.3 KiB
C

/*
* ARMv7M CPU object
*
* Copyright (c) 2017 Linaro Ltd
* Written by Peter Maydell <peter.maydell@linaro.org>
*
* This code is licensed under the GPL version 2 or later.
*/
#ifndef HW_ARM_ARMV7M_H
#define HW_ARM_ARMV7M_H
#include "hw/sysbus.h"
#include "hw/intc/armv7m_nvic.h"
#include "target/arm/idau.h"
#define TYPE_BITBAND "ARM,bitband-memory"
#define BITBAND(obj) OBJECT_CHECK(BitBandState, (obj), TYPE_BITBAND)
typedef struct {
/*< private >*/
SysBusDevice parent_obj;
/*< public >*/
AddressSpace source_as;
MemoryRegion iomem;
uint32_t base;
MemoryRegion *source_memory;
} BitBandState;
#define TYPE_ARMV7M "armv7m"
#define ARMV7M(obj) OBJECT_CHECK(ARMv7MState, (obj), TYPE_ARMV7M)
#define ARMV7M_NUM_BITBANDS 2
/* ARMv7M container object.
* + Unnamed GPIO input lines: external IRQ lines for the NVIC
* + Named GPIO output SYSRESETREQ: signalled for guest AIRCR.SYSRESETREQ.
* If this GPIO is not wired up then the NVIC will default to performing
* a qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET).
* + Property "cpu-type": CPU type to instantiate
* + Property "num-irq": number of external IRQ lines
* + Property "memory": MemoryRegion defining the physical address space
* that CPU accesses see. (The NVIC, bitbanding and other CPU-internal
* devices will be automatically layered on top of this view.)
* + Property "idau": IDAU interface (forwarded to CPU object)
* + Property "init-svtor": secure VTOR reset value (forwarded to CPU object)
* + Property "vfp": enable VFP (forwarded to CPU object)
* + Property "dsp": enable DSP (forwarded to CPU object)
* + Property "enable-bitband": expose bitbanded IO
*/
typedef struct ARMv7MState {
/*< private >*/
SysBusDevice parent_obj;
/*< public >*/
NVICState nvic;
BitBandState bitband[ARMV7M_NUM_BITBANDS];
ARMCPU *cpu;
/* MemoryRegion we pass to the CPU, with our devices layered on
* top of the ones the board provides in board_memory.
*/
MemoryRegion container;
/* Properties */
char *cpu_type;
/* MemoryRegion the board provides to us (with its devices, RAM, etc) */
MemoryRegion *board_memory;
Object *idau;
uint32_t init_svtor;
bool enable_bitband;
bool start_powered_off;
bool vfp;
bool dsp;
} ARMv7MState;
#endif