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Diffstat (limited to 'arch/nios2/kernel/setup.c')
| -rw-r--r-- | arch/nios2/kernel/setup.c | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/arch/nios2/kernel/setup.c b/arch/nios2/kernel/setup.c new file mode 100644 index 000000000000..cb3121f975d4 --- /dev/null +++ b/arch/nios2/kernel/setup.c @@ -0,0 +1,218 @@ +/* + * Nios2-specific parts of system setup + * + * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch> + * Copyright (C) 2004 Microtronix Datacom Ltd. + * Copyright (C) 2001 Vic Phillips <vic@microtronix.com> + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#include <linux/export.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/sched.h> +#include <linux/console.h> +#include <linux/bootmem.h> +#include <linux/initrd.h> +#include <linux/of_fdt.h> + +#include <asm/mmu_context.h> +#include <asm/sections.h> +#include <asm/setup.h> +#include <asm/cpuinfo.h> + +unsigned long memory_start; +EXPORT_SYMBOL(memory_start); + +unsigned long memory_end; +EXPORT_SYMBOL(memory_end); + +unsigned long memory_size; + +static struct pt_regs fake_regs = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, + 0}; + +/* Copy a short hook instruction sequence to the exception address */ +static inline void copy_exception_handler(unsigned int addr) +{ + unsigned int start = (unsigned int) exception_handler_hook; + volatile unsigned int tmp = 0; + + if (start == addr) { + /* The CPU exception address already points to the handler. */ + return; + } + + __asm__ __volatile__ ( + "ldw %2,0(%0)\n" + "stw %2,0(%1)\n" + "ldw %2,4(%0)\n" + "stw %2,4(%1)\n" + "ldw %2,8(%0)\n" + "stw %2,8(%1)\n" + "flushd 0(%1)\n" + "flushd 4(%1)\n" + "flushd 8(%1)\n" + "flushi %1\n" + "addi %1,%1,4\n" + "flushi %1\n" + "addi %1,%1,4\n" + "flushi %1\n" + "flushp\n" + : /* no output registers */ + : "r" (start), "r" (addr), "r" (tmp) + : "memory" + ); +} + +/* Copy the fast TLB miss handler */ +static inline void copy_fast_tlb_miss_handler(unsigned int addr) +{ + unsigned int start = (unsigned int) fast_handler; + unsigned int end = (unsigned int) fast_handler_end; + volatile unsigned int tmp = 0; + + __asm__ __volatile__ ( + "1:\n" + " ldw %3,0(%0)\n" + " stw %3,0(%1)\n" + " flushd 0(%1)\n" + " flushi %1\n" + " flushp\n" + " addi %0,%0,4\n" + " addi %1,%1,4\n" + " bne %0,%2,1b\n" + : /* no output registers */ + : "r" (start), "r" (addr), "r" (end), "r" (tmp) + : "memory" + ); +} + +/* + * save args passed from u-boot, called from head.S + * + * @r4: NIOS magic + * @r5: initrd start + * @r6: initrd end or fdt + * @r7: kernel command line + */ +asmlinkage void __init nios2_boot_init(unsigned r4, unsigned r5, unsigned r6, + unsigned r7) +{ + unsigned dtb_passed = 0; + char cmdline_passed[COMMAND_LINE_SIZE] = { 0, }; + +#if defined(CONFIG_NIOS2_PASS_CMDLINE) + if (r4 == 0x534f494e) { /* r4 is magic NIOS */ +#if defined(CONFIG_BLK_DEV_INITRD) + if (r5) { /* initramfs */ + initrd_start = r5; + initrd_end = r6; + } +#endif /* CONFIG_BLK_DEV_INITRD */ + dtb_passed = r6; + + if (r7) + strncpy(cmdline_passed, (char *)r7, COMMAND_LINE_SIZE); + } +#endif + + early_init_devtree((void *)dtb_passed); + +#ifndef CONFIG_CMDLINE_FORCE + if (cmdline_passed[0]) + strncpy(boot_command_line, cmdline_passed, COMMAND_LINE_SIZE); +#ifdef CONFIG_NIOS2_CMDLINE_IGNORE_DTB + else + strncpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE); +#endif +#endif +} + +void __init setup_arch(char **cmdline_p) +{ + int bootmap_size; + + console_verbose(); + + memory_start = PAGE_ALIGN((unsigned long)__pa(_end)); + memory_end = (unsigned long) CONFIG_NIOS2_MEM_BASE + memory_size; + + init_mm.start_code = (unsigned long) _stext; + init_mm.end_code = (unsigned long) _etext; + init_mm.end_data = (unsigned long) _edata; + init_mm.brk = (unsigned long) _end; + init_task.thread.kregs = &fake_regs; + + /* Keep a copy of command line */ + *cmdline_p = boot_command_line; + + min_low_pfn = PFN_UP(memory_start); + max_low_pfn = PFN_DOWN(memory_end); + max_mapnr = max_low_pfn; + + /* + * give all the memory to the bootmap allocator, tell it to put the + * boot mem_map at the start of memory + */ + pr_debug("init_bootmem_node(?,%#lx, %#x, %#lx)\n", + min_low_pfn, PFN_DOWN(PHYS_OFFSET), max_low_pfn); + bootmap_size = init_bootmem_node(NODE_DATA(0), + min_low_pfn, PFN_DOWN(PHYS_OFFSET), + max_low_pfn); + + /* + * free the usable memory, we have to make sure we do not free + * the bootmem bitmap so we then reserve it after freeing it :-) + */ + pr_debug("free_bootmem(%#lx, %#lx)\n", + memory_start, memory_end - memory_start); + free_bootmem(memory_start, memory_end - memory_start); + + /* + * Reserve the bootmem bitmap itself as well. We do this in two + * steps (first step was init_bootmem()) because this catches + * the (very unlikely) case of us accidentally initializing the + * bootmem allocator with an invalid RAM area. + * + * Arguments are start, size + */ + pr_debug("reserve_bootmem(%#lx, %#x)\n", memory_start, bootmap_size); + reserve_bootmem(memory_start, bootmap_size, BOOTMEM_DEFAULT); + +#ifdef CONFIG_BLK_DEV_INITRD + if (initrd_start) { + reserve_bootmem(virt_to_phys((void *)initrd_start), + initrd_end - initrd_start, BOOTMEM_DEFAULT); + } +#endif /* CONFIG_BLK_DEV_INITRD */ + + unflatten_and_copy_device_tree(); + + setup_cpuinfo(); + + copy_exception_handler(cpuinfo.exception_addr); + + mmu_init(); + + copy_fast_tlb_miss_handler(cpuinfo.fast_tlb_miss_exc_addr); + + /* + * Initialize MMU context handling here because data from cpuinfo is + * needed for this. + */ + mmu_context_init(); + + /* + * get kmalloc into gear + */ + paging_init(); + +#if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE) + conswitchp = &dummy_con; +#endif +} |