/*
* 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/sched/task.h>
#include <linux/console.h>
#include <linux/bootmem.h>
#include <linux/initrd.h>
#include <linux/of_fdt.h>
#include <linux/screen_info.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};
#ifdef CONFIG_VT
struct screen_info screen_info;
#endif
/* 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] __maybe_unused = { 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();
#ifdef CONFIG_EARLY_PRINTK
setup_early_printk();
#endif
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
}
