1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
4 #include <linux/console.h>
5 #include <linux/memblock.h>
6 #include <linux/initrd.h>
8 #include <linux/of_fdt.h>
9 #include <linux/start_kernel.h>
10 #include <linux/dma-map-ops.h>
11 #include <linux/screen_info.h>
12 #include <asm/sections.h>
13 #include <asm/mmu_context.h>
14 #include <asm/pgalloc.h>
16 #ifdef CONFIG_DUMMY_CONSOLE
17 struct screen_info screen_info = {
18 .orig_video_lines = 30,
19 .orig_video_cols = 80,
21 .orig_video_ega_bx = 0,
22 .orig_video_isVGA = 1,
23 .orig_video_points = 8
27 static void __init csky_memblock_init(void)
29 unsigned long lowmem_size = PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET);
30 unsigned long sseg_size = PFN_DOWN(SSEG_SIZE - PHYS_OFFSET_OFFSET);
31 unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
34 memblock_reserve(__pa(_stext), _end - _stext);
36 early_init_fdt_reserve_self();
37 early_init_fdt_scan_reserved_mem();
41 min_low_pfn = PFN_UP(memblock_start_of_DRAM());
42 max_low_pfn = max_pfn = PFN_DOWN(memblock_end_of_DRAM());
44 size = max_pfn - min_low_pfn;
46 if (size >= lowmem_size) {
47 max_low_pfn = min_low_pfn + lowmem_size;
48 #ifdef CONFIG_PAGE_OFFSET_80000000
49 write_mmu_msa1(read_mmu_msa0() + SSEG_SIZE);
51 } else if (size > sseg_size) {
52 max_low_pfn = min_low_pfn + sseg_size;
55 max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
57 mmu_init(min_low_pfn, max_low_pfn);
60 max_zone_pfn[ZONE_HIGHMEM] = max_pfn;
62 highstart_pfn = max_low_pfn;
63 highend_pfn = max_pfn;
65 memblock_set_current_limit(PFN_PHYS(max_low_pfn));
67 dma_contiguous_reserve(0);
69 free_area_init(max_zone_pfn);
72 void __init setup_arch(char **cmdline_p)
74 *cmdline_p = boot_command_line;
78 pr_info("Phys. mem: %ldMB\n",
79 (unsigned long) memblock_phys_mem_size()/1024/1024);
81 init_mm.start_code = (unsigned long) _stext;
82 init_mm.end_code = (unsigned long) _etext;
83 init_mm.end_data = (unsigned long) _edata;
84 init_mm.brk = (unsigned long) _end;
90 unflatten_and_copy_device_tree();
100 #ifdef CONFIG_HIGHMEM
105 unsigned long va_pa_offset;
106 EXPORT_SYMBOL(va_pa_offset);
108 static inline unsigned long read_mmu_msa(void)
110 #ifdef CONFIG_PAGE_OFFSET_80000000
111 return read_mmu_msa0();
114 #ifdef CONFIG_PAGE_OFFSET_A0000000
115 return read_mmu_msa1();
119 asmlinkage __visible void __init csky_start(unsigned int unused,
122 /* Clean up bss section */
123 memset(__bss_start, 0, __bss_stop - __bss_start);
125 va_pa_offset = read_mmu_msa() & ~(SSEG_SIZE - 1);
129 if (dtb_start == NULL)
130 early_init_dt_scan(__dtb_start);
132 early_init_dt_scan(dtb_start);
136 asm volatile("br .\n");