[PATCH V8 03/21] csky: Kernel booting

From: Guo Ren
Date: Fri Oct 12 2018 - 00:46:08 EST


This patch add boot code. Thx boot params is all in dtb and it's
the only way to let kernel get bootloader param information.

Changelog:
- Use built-in dtb when dtb param is NULL.
- Add dummy console for allmodconfig.

Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx>
---
arch/csky/kernel/head.S | 77 ++++++++++++++++++++
arch/csky/kernel/setup.c | 162 +++++++++++++++++++++++++++++++++++++++++
arch/csky/kernel/vmlinux.lds.S | 66 +++++++++++++++++
3 files changed, 305 insertions(+)
create mode 100644 arch/csky/kernel/head.S
create mode 100644 arch/csky/kernel/setup.c
create mode 100644 arch/csky/kernel/vmlinux.lds.S

diff --git a/arch/csky/kernel/head.S b/arch/csky/kernel/head.S
new file mode 100644
index 0000000..9c4ec47
--- /dev/null
+++ b/arch/csky/kernel/head.S
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/page.h>
+#include <abi/entry.h>
+
+__HEAD
+ENTRY(_start)
+ /* set super user mode */
+ lrw a3, DEFAULT_PSR_VALUE
+ mtcr a3, psr
+ psrset ee
+
+ SETUP_MMU a3
+
+ /* set stack point */
+ lrw a3, init_thread_union + THREAD_SIZE
+ mov sp, a3
+
+ jmpi csky_start
+END(_start)
+
+#ifdef CONFIG_SMP
+.align 10
+ENTRY(_start_smp_secondary)
+ /* Invalid I/Dcache BTB BHT */
+ movi a3, 7
+ lsli a3, 16
+ addi a3, (1<<4) | 3
+ mtcr a3, cr17
+
+ tlbi.alls
+
+ /* setup PAGEMASK */
+ movi a3, 0
+ mtcr a3, cr<6, 15>
+
+ /* setup MEL0/MEL1 */
+ grs a0, _start_smp_pc
+_start_smp_pc:
+ bmaski a1, 13
+ andn a0, a1
+ movi a1, 0x00000006
+ movi a2, 0x00001006
+ or a1, a0
+ or a2, a0
+ mtcr a1, cr<2, 15>
+ mtcr a2, cr<3, 15>
+
+ /* setup MEH */
+ mtcr a0, cr<4, 15>
+
+ /* write TLB */
+ bgeni a3, 28
+ mtcr a3, cr<8, 15>
+
+ SETUP_MMU a3
+
+ /* enable MMU */
+ movi a3, 1
+ mtcr a3, cr18
+
+ jmpi _goto_mmu_on
+_goto_mmu_on:
+ lrw a3, DEFAULT_PSR_VALUE
+ mtcr a3, psr
+ psrset ee
+
+ /* set stack point */
+ lrw a3, secondary_stack
+ ld.w a3, (a3, 0)
+ mov sp, a3
+
+ jmpi csky_start_secondary
+END(_start_smp_secondary)
+#endif
diff --git a/arch/csky/kernel/setup.c b/arch/csky/kernel/setup.c
new file mode 100644
index 0000000..a5e3ab1
--- /dev/null
+++ b/arch/csky/kernel/setup.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+
+#include <linux/console.h>
+#include <linux/memblock.h>
+#include <linux/bootmem.h>
+#include <linux/initrd.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/start_kernel.h>
+#include <linux/dma-contiguous.h>
+#include <linux/screen_info.h>
+#include <asm/sections.h>
+#include <asm/mmu_context.h>
+#include <asm/pgalloc.h>
+
+#ifdef CONFIG_DUMMY_CONSOLE
+struct screen_info screen_info = {
+ .orig_video_lines = 30,
+ .orig_video_cols = 80,
+ .orig_video_mode = 0,
+ .orig_video_ega_bx = 0,
+ .orig_video_isVGA = 1,
+ .orig_video_points = 8
+};
+#endif
+
+phys_addr_t __init_memblock memblock_end_of_REG0(void)
+{
+ return (memblock.memory.regions[0].base +
+ memblock.memory.regions[0].size);
+}
+
+phys_addr_t __init_memblock memblock_start_of_REG1(void)
+{
+ return memblock.memory.regions[1].base;
+}
+
+size_t __init_memblock memblock_size_of_REG1(void)
+{
+ return memblock.memory.regions[1].size;
+}
+
+static void __init csky_memblock_init(void)
+{
+ unsigned long zone_size[MAX_NR_ZONES];
+ unsigned long zhole_size[MAX_NR_ZONES];
+ signed long size;
+
+ memblock_reserve(__pa(_stext), _end - _stext);
+#ifdef CONFIG_BLK_DEV_INITRD
+ memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
+#endif
+
+ early_init_fdt_reserve_self();
+ early_init_fdt_scan_reserved_mem();
+
+ memblock_dump_all();
+
+ memset(zone_size, 0, sizeof(zone_size));
+ memset(zhole_size, 0, sizeof(zhole_size));
+
+ min_low_pfn = PFN_UP(memblock_start_of_DRAM());
+ max_pfn = PFN_DOWN(memblock_end_of_DRAM());
+
+ max_low_pfn = PFN_UP(memblock_end_of_REG0());
+ if (max_low_pfn == 0)
+ max_low_pfn = max_pfn;
+
+ size = max_pfn - min_low_pfn;
+
+ if (memblock.memory.cnt > 1) {
+ zone_size[ZONE_NORMAL] =
+ PFN_DOWN(memblock_start_of_REG1()) - min_low_pfn;
+ zhole_size[ZONE_NORMAL] =
+ PFN_DOWN(memblock_start_of_REG1()) - max_low_pfn;
+ } else {
+ if (size <= PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET))
+ zone_size[ZONE_NORMAL] = max_pfn - min_low_pfn;
+ else {
+ zone_size[ZONE_NORMAL] =
+ PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET);
+ max_low_pfn = min_low_pfn + zone_size[ZONE_NORMAL];
+ }
+ }
+
+#ifdef CONFIG_HIGHMEM
+ size = 0;
+ if (memblock.memory.cnt > 1) {
+ size = PFN_DOWN(memblock_size_of_REG1());
+ highstart_pfn = PFN_DOWN(memblock_start_of_REG1());
+ } else {
+ size = max_pfn - min_low_pfn -
+ PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET);
+ highstart_pfn = min_low_pfn +
+ PFN_DOWN(LOWMEM_LIMIT - PHYS_OFFSET_OFFSET);
+ }
+
+ if (size > 0)
+ zone_size[ZONE_HIGHMEM] = size;
+
+ highend_pfn = max_pfn;
+#endif
+ memblock_set_current_limit(PFN_PHYS(max_low_pfn));
+
+ dma_contiguous_reserve(0);
+
+ free_area_init_node(0, zone_size, min_low_pfn, zhole_size);
+}
+
+void __init setup_arch(char **cmdline_p)
+{
+ *cmdline_p = boot_command_line;
+
+ console_verbose();
+
+ pr_info("Phys. mem: %ldMB\n",
+ (unsigned long) memblock_phys_mem_size()/1024/1024);
+
+ 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;
+
+ parse_early_param();
+
+ csky_memblock_init();
+
+ unflatten_and_copy_device_tree();
+
+#ifdef CONFIG_SMP
+ setup_smp();
+#endif
+
+ sparse_init();
+
+#ifdef CONFIG_HIGHMEM
+ kmap_init();
+#endif
+
+#if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
+ conswitchp = &dummy_con;
+#endif
+}
+
+asmlinkage __visible void __init csky_start(unsigned int unused, void *param)
+{
+ /* Clean up bss section */
+ memset(__bss_start, 0, __bss_stop - __bss_start);
+
+ pre_trap_init();
+ pre_mmu_init();
+
+ if (param == NULL)
+ early_init_dt_scan(__dtb_start);
+ else
+ early_init_dt_scan(param);
+
+ start_kernel();
+
+ asm volatile("br .\n");
+}
diff --git a/arch/csky/kernel/vmlinux.lds.S b/arch/csky/kernel/vmlinux.lds.S
new file mode 100644
index 0000000..ae7961b
--- /dev/null
+++ b/arch/csky/kernel/vmlinux.lds.S
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <asm/vmlinux.lds.h>
+#include <asm/page.h>
+
+OUTPUT_ARCH(csky)
+ENTRY(_start)
+
+#ifndef __cskyBE__
+jiffies = jiffies_64;
+#else
+jiffies = jiffies_64 + 4;
+#endif
+
+#define VBR_BASE \
+ . = ALIGN(1024); \
+ vec_base = .; \
+ . += 512;
+
+SECTIONS
+{
+ . = PAGE_OFFSET + PHYS_OFFSET_OFFSET;
+
+ _stext = .;
+ __init_begin = .;
+ HEAD_TEXT_SECTION
+ INIT_TEXT_SECTION(PAGE_SIZE)
+ INIT_DATA_SECTION(PAGE_SIZE)
+ PERCPU_SECTION(L1_CACHE_BYTES)
+ . = ALIGN(PAGE_SIZE);
+ __init_end = .;
+
+ .text : AT(ADDR(.text) - LOAD_OFFSET) {
+ _text = .;
+ IRQENTRY_TEXT
+ SOFTIRQENTRY_TEXT
+ TEXT_TEXT
+ SCHED_TEXT
+ CPUIDLE_TEXT
+ LOCK_TEXT
+ KPROBES_TEXT
+ *(.fixup)
+ *(.gnu.warning)
+ } = 0
+ _etext = .;
+
+ /* __init_begin __init_end must be page aligned for free_initmem */
+ . = ALIGN(PAGE_SIZE);
+
+
+ _sdata = .;
+ RO_DATA_SECTION(PAGE_SIZE)
+ RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
+ _edata = .;
+
+ NOTES
+ EXCEPTION_TABLE(L1_CACHE_BYTES)
+ BSS_SECTION(L1_CACHE_BYTES, PAGE_SIZE, L1_CACHE_BYTES)
+ VBR_BASE
+ _end = . ;
+
+ STABS_DEBUG
+ DWARF_DEBUG
+
+ DISCARDS
+}
--
2.7.4