From 542b3478a00cb7ef51c259255b3ab1e2a7daada2 Mon Sep 17 00:00:00 2001 From: Michael Davidsaver Date: Fri, 27 Jan 2017 15:20:21 +0000 Subject: armv7m: Replace armv7m.hack with unassigned_access handler For v7m we need to catch attempts to execute from special addresses at 0xfffffff0 and above. Previously we did this with the aid of a hacky special purpose lump of memory in the address space and a check in translate.c for whether we were translating code at those addresses. We can implement this more cleanly using a CPU unassigned access handler which throws the exception if the unassigned access is for one of the special addresses. Signed-off-by: Michael Davidsaver Reviewed-by: Alex Bennée Message-id: 1484937883-1068-3-git-send-email-peter.maydell@linaro.org [PMM: * drop the deletion of the "don't interrupt if PC is magic" code in arm_v7m_cpu_exec_interrupt() -- this is still required * don't generate an exception for unassigned accesses which aren't to the magic address -- although doing this is in theory correct in practice it will break currently working guests which rely on the RAZ/WI behaviour when they touch devices which we haven't modelled. * trigger EXCP_EXCEPTION_EXIT on is_exec, not !is_write ] Signed-off-by: Peter Maydell --- hw/arm/armv7m.c | 8 -------- 1 file changed, 8 deletions(-) (limited to 'hw') diff --git a/hw/arm/armv7m.c b/hw/arm/armv7m.c index 49d30782c8..0c9ca7bfa0 100644 --- a/hw/arm/armv7m.c +++ b/hw/arm/armv7m.c @@ -180,7 +180,6 @@ DeviceState *armv7m_init(MemoryRegion *system_memory, int mem_size, int num_irq, uint64_t entry; uint64_t lowaddr; int big_endian; - MemoryRegion *hack = g_new(MemoryRegion, 1); if (cpu_model == NULL) { cpu_model = "cortex-m3"; @@ -225,13 +224,6 @@ DeviceState *armv7m_init(MemoryRegion *system_memory, int mem_size, int num_irq, } } - /* Hack to map an additional page of ram at the top of the address - space. This stops qemu complaining about executing code outside RAM - when returning from an exception. */ - memory_region_init_ram(hack, NULL, "armv7m.hack", 0x1000, &error_fatal); - vmstate_register_ram_global(hack); - memory_region_add_subregion(system_memory, 0xfffff000, hack); - qemu_register_reset(armv7m_reset, cpu); return nvic; } -- cgit v1.2.3-55-g7522