xref: /openbmc/qemu/hw/arm/armv7m.c (revision 1fd6bb44)
1 /*
2  * ARMV7M System emulation.
3  *
4  * Copyright (c) 2006-2007 CodeSourcery.
5  * Written by Paul Brook
6  *
7  * This code is licensed under the GPL.
8  */
9 
10 #include "hw/sysbus.h"
11 #include "hw/arm.h"
12 #include "hw/loader.h"
13 #include "elf.h"
14 
15 /* Bitbanded IO.  Each word corresponds to a single bit.  */
16 
17 /* Get the byte address of the real memory for a bitband access.  */
18 static inline uint32_t bitband_addr(void * opaque, uint32_t addr)
19 {
20     uint32_t res;
21 
22     res = *(uint32_t *)opaque;
23     res |= (addr & 0x1ffffff) >> 5;
24     return res;
25 
26 }
27 
28 static uint32_t bitband_readb(void *opaque, hwaddr offset)
29 {
30     uint8_t v;
31     cpu_physical_memory_read(bitband_addr(opaque, offset), &v, 1);
32     return (v & (1 << ((offset >> 2) & 7))) != 0;
33 }
34 
35 static void bitband_writeb(void *opaque, hwaddr offset,
36                            uint32_t value)
37 {
38     uint32_t addr;
39     uint8_t mask;
40     uint8_t v;
41     addr = bitband_addr(opaque, offset);
42     mask = (1 << ((offset >> 2) & 7));
43     cpu_physical_memory_read(addr, &v, 1);
44     if (value & 1)
45         v |= mask;
46     else
47         v &= ~mask;
48     cpu_physical_memory_write(addr, &v, 1);
49 }
50 
51 static uint32_t bitband_readw(void *opaque, hwaddr offset)
52 {
53     uint32_t addr;
54     uint16_t mask;
55     uint16_t v;
56     addr = bitband_addr(opaque, offset) & ~1;
57     mask = (1 << ((offset >> 2) & 15));
58     mask = tswap16(mask);
59     cpu_physical_memory_read(addr, (uint8_t *)&v, 2);
60     return (v & mask) != 0;
61 }
62 
63 static void bitband_writew(void *opaque, hwaddr offset,
64                            uint32_t value)
65 {
66     uint32_t addr;
67     uint16_t mask;
68     uint16_t v;
69     addr = bitband_addr(opaque, offset) & ~1;
70     mask = (1 << ((offset >> 2) & 15));
71     mask = tswap16(mask);
72     cpu_physical_memory_read(addr, (uint8_t *)&v, 2);
73     if (value & 1)
74         v |= mask;
75     else
76         v &= ~mask;
77     cpu_physical_memory_write(addr, (uint8_t *)&v, 2);
78 }
79 
80 static uint32_t bitband_readl(void *opaque, hwaddr offset)
81 {
82     uint32_t addr;
83     uint32_t mask;
84     uint32_t v;
85     addr = bitband_addr(opaque, offset) & ~3;
86     mask = (1 << ((offset >> 2) & 31));
87     mask = tswap32(mask);
88     cpu_physical_memory_read(addr, (uint8_t *)&v, 4);
89     return (v & mask) != 0;
90 }
91 
92 static void bitband_writel(void *opaque, hwaddr offset,
93                            uint32_t value)
94 {
95     uint32_t addr;
96     uint32_t mask;
97     uint32_t v;
98     addr = bitband_addr(opaque, offset) & ~3;
99     mask = (1 << ((offset >> 2) & 31));
100     mask = tswap32(mask);
101     cpu_physical_memory_read(addr, (uint8_t *)&v, 4);
102     if (value & 1)
103         v |= mask;
104     else
105         v &= ~mask;
106     cpu_physical_memory_write(addr, (uint8_t *)&v, 4);
107 }
108 
109 static const MemoryRegionOps bitband_ops = {
110     .old_mmio = {
111         .read = { bitband_readb, bitband_readw, bitband_readl, },
112         .write = { bitband_writeb, bitband_writew, bitband_writel, },
113     },
114     .endianness = DEVICE_NATIVE_ENDIAN,
115 };
116 
117 typedef struct {
118     SysBusDevice busdev;
119     MemoryRegion iomem;
120     uint32_t base;
121 } BitBandState;
122 
123 static int bitband_init(SysBusDevice *dev)
124 {
125     BitBandState *s = FROM_SYSBUS(BitBandState, dev);
126 
127     memory_region_init_io(&s->iomem, &bitband_ops, &s->base, "bitband",
128                           0x02000000);
129     sysbus_init_mmio(dev, &s->iomem);
130     return 0;
131 }
132 
133 static void armv7m_bitband_init(void)
134 {
135     DeviceState *dev;
136 
137     dev = qdev_create(NULL, "ARM,bitband-memory");
138     qdev_prop_set_uint32(dev, "base", 0x20000000);
139     qdev_init_nofail(dev);
140     sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, 0x22000000);
141 
142     dev = qdev_create(NULL, "ARM,bitband-memory");
143     qdev_prop_set_uint32(dev, "base", 0x40000000);
144     qdev_init_nofail(dev);
145     sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, 0x42000000);
146 }
147 
148 /* Board init.  */
149 
150 static void armv7m_reset(void *opaque)
151 {
152     ARMCPU *cpu = opaque;
153 
154     cpu_reset(CPU(cpu));
155 }
156 
157 /* Init CPU and memory for a v7-M based board.
158    flash_size and sram_size are in kb.
159    Returns the NVIC array.  */
160 
161 qemu_irq *armv7m_init(MemoryRegion *address_space_mem,
162                       int flash_size, int sram_size,
163                       const char *kernel_filename, const char *cpu_model)
164 {
165     ARMCPU *cpu;
166     CPUARMState *env;
167     DeviceState *nvic;
168     /* FIXME: make this local state.  */
169     static qemu_irq pic[64];
170     qemu_irq *cpu_pic;
171     int image_size;
172     uint64_t entry;
173     uint64_t lowaddr;
174     int i;
175     int big_endian;
176     MemoryRegion *sram = g_new(MemoryRegion, 1);
177     MemoryRegion *flash = g_new(MemoryRegion, 1);
178     MemoryRegion *hack = g_new(MemoryRegion, 1);
179 
180     flash_size *= 1024;
181     sram_size *= 1024;
182 
183     if (cpu_model == NULL) {
184 	cpu_model = "cortex-m3";
185     }
186     cpu = cpu_arm_init(cpu_model);
187     if (cpu == NULL) {
188         fprintf(stderr, "Unable to find CPU definition\n");
189         exit(1);
190     }
191     env = &cpu->env;
192 
193 #if 0
194     /* > 32Mb SRAM gets complicated because it overlaps the bitband area.
195        We don't have proper commandline options, so allocate half of memory
196        as SRAM, up to a maximum of 32Mb, and the rest as code.  */
197     if (ram_size > (512 + 32) * 1024 * 1024)
198         ram_size = (512 + 32) * 1024 * 1024;
199     sram_size = (ram_size / 2) & TARGET_PAGE_MASK;
200     if (sram_size > 32 * 1024 * 1024)
201         sram_size = 32 * 1024 * 1024;
202     code_size = ram_size - sram_size;
203 #endif
204 
205     /* Flash programming is done via the SCU, so pretend it is ROM.  */
206     memory_region_init_ram(flash, "armv7m.flash", flash_size);
207     vmstate_register_ram_global(flash);
208     memory_region_set_readonly(flash, true);
209     memory_region_add_subregion(address_space_mem, 0, flash);
210     memory_region_init_ram(sram, "armv7m.sram", sram_size);
211     vmstate_register_ram_global(sram);
212     memory_region_add_subregion(address_space_mem, 0x20000000, sram);
213     armv7m_bitband_init();
214 
215     nvic = qdev_create(NULL, "armv7m_nvic");
216     env->nvic = nvic;
217     qdev_init_nofail(nvic);
218     cpu_pic = arm_pic_init_cpu(cpu);
219     sysbus_connect_irq(SYS_BUS_DEVICE(nvic), 0, cpu_pic[ARM_PIC_CPU_IRQ]);
220     for (i = 0; i < 64; i++) {
221         pic[i] = qdev_get_gpio_in(nvic, i);
222     }
223 
224 #ifdef TARGET_WORDS_BIGENDIAN
225     big_endian = 1;
226 #else
227     big_endian = 0;
228 #endif
229 
230     if (!kernel_filename) {
231         fprintf(stderr, "Guest image must be specified (using -kernel)\n");
232         exit(1);
233     }
234 
235     image_size = load_elf(kernel_filename, NULL, NULL, &entry, &lowaddr,
236                           NULL, big_endian, ELF_MACHINE, 1);
237     if (image_size < 0) {
238         image_size = load_image_targphys(kernel_filename, 0, flash_size);
239 	lowaddr = 0;
240     }
241     if (image_size < 0) {
242         fprintf(stderr, "qemu: could not load kernel '%s'\n",
243                 kernel_filename);
244         exit(1);
245     }
246 
247     /* Hack to map an additional page of ram at the top of the address
248        space.  This stops qemu complaining about executing code outside RAM
249        when returning from an exception.  */
250     memory_region_init_ram(hack, "armv7m.hack", 0x1000);
251     vmstate_register_ram_global(hack);
252     memory_region_add_subregion(address_space_mem, 0xfffff000, hack);
253 
254     qemu_register_reset(armv7m_reset, cpu);
255     return pic;
256 }
257 
258 static Property bitband_properties[] = {
259     DEFINE_PROP_UINT32("base", BitBandState, base, 0),
260     DEFINE_PROP_END_OF_LIST(),
261 };
262 
263 static void bitband_class_init(ObjectClass *klass, void *data)
264 {
265     DeviceClass *dc = DEVICE_CLASS(klass);
266     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
267 
268     k->init = bitband_init;
269     dc->props = bitband_properties;
270 }
271 
272 static const TypeInfo bitband_info = {
273     .name          = "ARM,bitband-memory",
274     .parent        = TYPE_SYS_BUS_DEVICE,
275     .instance_size = sizeof(BitBandState),
276     .class_init    = bitband_class_init,
277 };
278 
279 static void armv7m_register_types(void)
280 {
281     type_register_static(&bitband_info);
282 }
283 
284 type_init(armv7m_register_types)
285