arm64: Kernel booting and initialisation
The patch adds the kernel booting and the initial setup code.
Documentation/arm64/booting.txt describes the booting protocol on the
AArch64 Linux kernel. This is subject to change following the work on
boot standardisation, ACPI.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
new file mode 100644
index 0000000..48ffb9f
--- /dev/null
+++ b/arch/arm64/kernel/setup.c
@@ -0,0 +1,347 @@
+/*
+ * Based on arch/arm/kernel/setup.c
+ *
+ * Copyright (C) 1995-2001 Russell King
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/stddef.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/utsname.h>
+#include <linux/initrd.h>
+#include <linux/console.h>
+#include <linux/bootmem.h>
+#include <linux/seq_file.h>
+#include <linux/screen_info.h>
+#include <linux/init.h>
+#include <linux/kexec.h>
+#include <linux/crash_dump.h>
+#include <linux/root_dev.h>
+#include <linux/cpu.h>
+#include <linux/interrupt.h>
+#include <linux/smp.h>
+#include <linux/fs.h>
+#include <linux/proc_fs.h>
+#include <linux/memblock.h>
+#include <linux/of_fdt.h>
+
+#include <asm/cputype.h>
+#include <asm/elf.h>
+#include <asm/cputable.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/traps.h>
+#include <asm/memblock.h>
+
+unsigned int processor_id;
+EXPORT_SYMBOL(processor_id);
+
+unsigned int elf_hwcap __read_mostly;
+EXPORT_SYMBOL_GPL(elf_hwcap);
+
+static const char *cpu_name;
+static const char *machine_name;
+phys_addr_t __fdt_pointer __initdata;
+
+/*
+ * Standard memory resources
+ */
+static struct resource mem_res[] = {
+ {
+ .name = "Kernel code",
+ .start = 0,
+ .end = 0,
+ .flags = IORESOURCE_MEM
+ },
+ {
+ .name = "Kernel data",
+ .start = 0,
+ .end = 0,
+ .flags = IORESOURCE_MEM
+ }
+};
+
+#define kernel_code mem_res[0]
+#define kernel_data mem_res[1]
+
+void __init early_print(const char *str, ...)
+{
+ char buf[256];
+ va_list ap;
+
+ va_start(ap, str);
+ vsnprintf(buf, sizeof(buf), str, ap);
+ va_end(ap);
+
+ printk("%s", buf);
+}
+
+static void __init setup_processor(void)
+{
+ struct cpu_info *cpu_info;
+
+ /*
+ * locate processor in the list of supported processor
+ * types. The linker builds this table for us from the
+ * entries in arch/arm/mm/proc.S
+ */
+ cpu_info = lookup_processor_type(read_cpuid_id());
+ if (!cpu_info) {
+ printk("CPU configuration botched (ID %08x), unable to continue.\n",
+ read_cpuid_id());
+ while (1);
+ }
+
+ cpu_name = cpu_info->cpu_name;
+
+ printk("CPU: %s [%08x] revision %d\n",
+ cpu_name, read_cpuid_id(), read_cpuid_id() & 15);
+
+ sprintf(init_utsname()->machine, "aarch64");
+ elf_hwcap = 0;
+}
+
+static void __init setup_machine_fdt(phys_addr_t dt_phys)
+{
+ struct boot_param_header *devtree;
+ unsigned long dt_root;
+
+ /* Check we have a non-NULL DT pointer */
+ if (!dt_phys) {
+ early_print("\n"
+ "Error: NULL or invalid device tree blob\n"
+ "The dtb must be 8-byte aligned and passed in the first 512MB of memory\n"
+ "\nPlease check your bootloader.\n");
+
+ while (true)
+ cpu_relax();
+
+ }
+
+ devtree = phys_to_virt(dt_phys);
+
+ /* Check device tree validity */
+ if (be32_to_cpu(devtree->magic) != OF_DT_HEADER) {
+ early_print("\n"
+ "Error: invalid device tree blob at physical address 0x%p (virtual address 0x%p)\n"
+ "Expected 0x%x, found 0x%x\n"
+ "\nPlease check your bootloader.\n",
+ dt_phys, devtree, OF_DT_HEADER,
+ be32_to_cpu(devtree->magic));
+
+ while (true)
+ cpu_relax();
+ }
+
+ initial_boot_params = devtree;
+ dt_root = of_get_flat_dt_root();
+
+ machine_name = of_get_flat_dt_prop(dt_root, "model", NULL);
+ if (!machine_name)
+ machine_name = of_get_flat_dt_prop(dt_root, "compatible", NULL);
+ if (!machine_name)
+ machine_name = "<unknown>";
+ pr_info("Machine: %s\n", machine_name);
+
+ /* Retrieve various information from the /chosen node */
+ of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
+ /* Initialize {size,address}-cells info */
+ of_scan_flat_dt(early_init_dt_scan_root, NULL);
+ /* Setup memory, calling early_init_dt_add_memory_arch */
+ of_scan_flat_dt(early_init_dt_scan_memory, NULL);
+}
+
+void __init early_init_dt_add_memory_arch(u64 base, u64 size)
+{
+ size &= PAGE_MASK;
+ memblock_add(base, size);
+}
+
+void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
+{
+ return __va(memblock_alloc(size, align));
+}
+
+/*
+ * Limit the memory size that was specified via FDT.
+ */
+static int __init early_mem(char *p)
+{
+ phys_addr_t limit;
+
+ if (!p)
+ return 1;
+
+ limit = memparse(p, &p) & PAGE_MASK;
+ pr_notice("Memory limited to %lldMB\n", limit >> 20);
+
+ memblock_enforce_memory_limit(limit);
+
+ return 0;
+}
+early_param("mem", early_mem);
+
+static void __init request_standard_resources(void)
+{
+ struct memblock_region *region;
+ struct resource *res;
+
+ kernel_code.start = virt_to_phys(_text);
+ kernel_code.end = virt_to_phys(_etext - 1);
+ kernel_data.start = virt_to_phys(_sdata);
+ kernel_data.end = virt_to_phys(_end - 1);
+
+ for_each_memblock(memory, region) {
+ res = alloc_bootmem_low(sizeof(*res));
+ res->name = "System RAM";
+ res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
+ res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
+ res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+
+ request_resource(&iomem_resource, res);
+
+ if (kernel_code.start >= res->start &&
+ kernel_code.end <= res->end)
+ request_resource(res, &kernel_code);
+ if (kernel_data.start >= res->start &&
+ kernel_data.end <= res->end)
+ request_resource(res, &kernel_data);
+ }
+}
+
+void __init setup_arch(char **cmdline_p)
+{
+ setup_processor();
+
+ setup_machine_fdt(__fdt_pointer);
+
+ init_mm.start_code = (unsigned long) _text;
+ init_mm.end_code = (unsigned long) _etext;
+ init_mm.end_data = (unsigned long) _edata;
+ init_mm.brk = (unsigned long) _end;
+
+ *cmdline_p = boot_command_line;
+
+ parse_early_param();
+
+ arm64_memblock_init();
+
+ paging_init();
+ request_standard_resources();
+
+ unflatten_device_tree();
+
+#ifdef CONFIG_SMP
+ smp_init_cpus();
+#endif
+
+#ifdef CONFIG_VT
+#if defined(CONFIG_VGA_CONSOLE)
+ conswitchp = &vga_con;
+#elif defined(CONFIG_DUMMY_CONSOLE)
+ conswitchp = &dummy_con;
+#endif
+#endif
+}
+
+static DEFINE_PER_CPU(struct cpu, cpu_data);
+
+static int __init topology_init(void)
+{
+ int i;
+
+ for_each_possible_cpu(i) {
+ struct cpu *cpu = &per_cpu(cpu_data, i);
+ cpu->hotpluggable = 1;
+ register_cpu(cpu, i);
+ }
+
+ return 0;
+}
+subsys_initcall(topology_init);
+
+static const char *hwcap_str[] = {
+ "fp",
+ "asimd",
+ NULL
+};
+
+static int c_show(struct seq_file *m, void *v)
+{
+ int i;
+
+ seq_printf(m, "Processor\t: %s rev %d (%s)\n",
+ cpu_name, read_cpuid_id() & 15, ELF_PLATFORM);
+
+ for_each_online_cpu(i) {
+ /*
+ * glibc reads /proc/cpuinfo to determine the number of
+ * online processors, looking for lines beginning with
+ * "processor". Give glibc what it expects.
+ */
+#ifdef CONFIG_SMP
+ seq_printf(m, "processor\t: %d\n", i);
+#endif
+ seq_printf(m, "BogoMIPS\t: %lu.%02lu\n\n",
+ loops_per_jiffy / (500000UL/HZ),
+ loops_per_jiffy / (5000UL/HZ) % 100);
+ }
+
+ /* dump out the processor features */
+ seq_puts(m, "Features\t: ");
+
+ for (i = 0; hwcap_str[i]; i++)
+ if (elf_hwcap & (1 << i))
+ seq_printf(m, "%s ", hwcap_str[i]);
+
+ seq_printf(m, "\nCPU implementer\t: 0x%02x\n", read_cpuid_id() >> 24);
+ seq_printf(m, "CPU architecture: AArch64\n");
+ seq_printf(m, "CPU variant\t: 0x%x\n", (read_cpuid_id() >> 20) & 15);
+ seq_printf(m, "CPU part\t: 0x%03x\n", (read_cpuid_id() >> 4) & 0xfff);
+ seq_printf(m, "CPU revision\t: %d\n", read_cpuid_id() & 15);
+
+ seq_puts(m, "\n");
+
+ seq_printf(m, "Hardware\t: %s\n", machine_name);
+
+ return 0;
+}
+
+static void *c_start(struct seq_file *m, loff_t *pos)
+{
+ return *pos < 1 ? (void *)1 : NULL;
+}
+
+static void *c_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ ++*pos;
+ return NULL;
+}
+
+static void c_stop(struct seq_file *m, void *v)
+{
+}
+
+const struct seq_operations cpuinfo_op = {
+ .start = c_start,
+ .next = c_next,
+ .stop = c_stop,
+ .show = c_show
+};