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/*
* ARMV7M System emulation.
*
* Copyright (c) 2006-2007 CodeSourcery.
* Written by Paul Brook
*
* This code is licenced under the GPL.
*/
#include "hw.h"
#include "arm-misc.h"
#include "sysemu.h"
/* Bitbanded IO. Each word corresponds to a single bit. */
/* Get the byte address of the real memory for a bitband acess. */
static inline uint32_t bitband_addr(void * opaque, uint32_t addr)
{
uint32_t res;
res = *(uint32_t *)opaque;
res |= (addr & 0x1ffffff) >> 5;
return res;
}
static uint32_t bitband_readb(void *opaque, target_phys_addr_t offset)
{
uint8_t v;
cpu_physical_memory_read(bitband_addr(opaque, offset), &v, 1);
return (v & (1 << ((offset >> 2) & 7))) != 0;
}
static void bitband_writeb(void *opaque, target_phys_addr_t offset,
uint32_t value)
{
uint32_t addr;
uint8_t mask;
uint8_t v;
addr = bitband_addr(opaque, offset);
mask = (1 << ((offset >> 2) & 7));
cpu_physical_memory_read(addr, &v, 1);
if (value & 1)
v |= mask;
else
v &= ~mask;
cpu_physical_memory_write(addr, &v, 1);
}
static uint32_t bitband_readw(void *opaque, target_phys_addr_t offset)
{
uint32_t addr;
uint16_t mask;
uint16_t v;
addr = bitband_addr(opaque, offset) & ~1;
mask = (1 << ((offset >> 2) & 15));
mask = tswap16(mask);
cpu_physical_memory_read(addr, (uint8_t *)&v, 2);
return (v & mask) != 0;
}
static void bitband_writew(void *opaque, target_phys_addr_t offset,
uint32_t value)
{
uint32_t addr;
uint16_t mask;
uint16_t v;
addr = bitband_addr(opaque, offset) & ~1;
mask = (1 << ((offset >> 2) & 15));
mask = tswap16(mask);
cpu_physical_memory_read(addr, (uint8_t *)&v, 2);
if (value & 1)
v |= mask;
else
v &= ~mask;
cpu_physical_memory_write(addr, (uint8_t *)&v, 2);
}
static uint32_t bitband_readl(void *opaque, target_phys_addr_t offset)
{
uint32_t addr;
uint32_t mask;
uint32_t v;
addr = bitband_addr(opaque, offset) & ~3;
mask = (1 << ((offset >> 2) & 31));
mask = tswap32(mask);
cpu_physical_memory_read(addr, (uint8_t *)&v, 4);
return (v & mask) != 0;
}
static void bitband_writel(void *opaque, target_phys_addr_t offset,
uint32_t value)
{
uint32_t addr;
uint32_t mask;
uint32_t v;
addr = bitband_addr(opaque, offset) & ~3;
mask = (1 << ((offset >> 2) & 31));
mask = tswap32(mask);
cpu_physical_memory_read(addr, (uint8_t *)&v, 4);
if (value & 1)
v |= mask;
else
v &= ~mask;
cpu_physical_memory_write(addr, (uint8_t *)&v, 4);
}
static CPUReadMemoryFunc *bitband_readfn[] = {
bitband_readb,
bitband_readw,
bitband_readl
};
static CPUWriteMemoryFunc *bitband_writefn[] = {
bitband_writeb,
bitband_writew,
bitband_writel
};
static void armv7m_bitband_init(void)
{
int iomemtype;
static uint32_t bitband1_offset = 0x20000000;
static uint32_t bitband2_offset = 0x40000000;
iomemtype = cpu_register_io_memory(0, bitband_readfn, bitband_writefn,
&bitband1_offset);
cpu_register_physical_memory(0x22000000, 0x02000000, iomemtype);
iomemtype = cpu_register_io_memory(0, bitband_readfn, bitband_writefn,
&bitband2_offset);
cpu_register_physical_memory(0x42000000, 0x02000000, iomemtype);
}
/* Board init. */
/* Init CPU and memory for a v7-M based board.
flash_size and sram_size are in kb.
Returns the NVIC array. */
qemu_irq *armv7m_init(int flash_size, int sram_size,
const char *kernel_filename, const char *cpu_model)
{
CPUState *env;
qemu_irq *pic;
uint32_t pc;
int image_size;
uint64_t entry;
uint64_t lowaddr;
flash_size *= 1024;
sram_size *= 1024;
if (!cpu_model)
cpu_model = "cortex-m3";
env = cpu_init(cpu_model);
if (!env) {
fprintf(stderr, "Unable to find CPU definition\n");
exit(1);
}
#if 0
/* > 32Mb SRAM gets complicated because it overlaps the bitband area.
We don't have proper commandline options, so allocate half of memory
as SRAM, up to a maximum of 32Mb, and the rest as code. */
if (ram_size > (512 + 32) * 1024 * 1024)
ram_size = (512 + 32) * 1024 * 1024;
sram_size = (ram_size / 2) & TARGET_PAGE_MASK;
if (sram_size > 32 * 1024 * 1024)
sram_size = 32 * 1024 * 1024;
code_size = ram_size - sram_size;
#endif
/* Flash programming is done via the SCU, so pretend it is ROM. */
cpu_register_physical_memory(0, flash_size,
qemu_ram_alloc(flash_size) | IO_MEM_ROM);
cpu_register_physical_memory(0x20000000, sram_size,
qemu_ram_alloc(sram_size) | IO_MEM_RAM);
armv7m_bitband_init();
pic = armv7m_nvic_init(env);
image_size = load_elf(kernel_filename, 0, &entry, &lowaddr, NULL);
if (image_size < 0) {
image_size = load_image_targphys(kernel_filename, 0, flash_size);
lowaddr = 0;
}
if (image_size < 0) {
fprintf(stderr, "qemu: could not load kernel '%s'\n",
kernel_filename);
exit(1);
}
/* If the image was loaded at address zero then assume it is a
regular ROM image and perform the normal CPU reset sequence.
Otherwise jump directly to the entry point. */
if (lowaddr == 0) {
env->regs[13] = ldl_phys(0);
pc = ldl_phys(4);
} else {
pc = entry;
}
env->thumb = pc & 1;
env->regs[15] = pc & ~1;
/* 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. */
cpu_register_physical_memory(0xfffff000, 0x1000,
qemu_ram_alloc(0x1000) | IO_MEM_RAM);
return pic;
}
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