[PATCH 01/19] csky: Kernel booting

From: Guo Ren
Date: Sun Mar 18 2018 - 15:54:42 EST


Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx>
---
arch/csky/kernel/head.S | 20 ++++++
arch/csky/kernel/setup.c | 157 +++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 177 insertions(+)
create mode 100644 arch/csky/kernel/head.S
create mode 100644 arch/csky/kernel/setup.c

diff --git a/arch/csky/kernel/head.S b/arch/csky/kernel/head.S
new file mode 100644
index 0000000..a746caf
--- /dev/null
+++ b/arch/csky/kernel/head.S
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/page.h>
+#include <abi/regdef.h>
+
+ENTRY(_start)
+ /* set super user mode */
+ lrw a3, DEFAULT_PSR_VALUE
+ mtcr a3, psr
+ psrset ee
+
+ /* set stack point */
+ lrw a3, init_thread_union + THREAD_SIZE
+ mov sp, a3
+
+ jmpi csky_start
+END(_start)
+
diff --git a/arch/csky/kernel/setup.c b/arch/csky/kernel/setup.c
new file mode 100644
index 0000000..04c9fbd
--- /dev/null
+++ b/arch/csky/kernel/setup.c
@@ -0,0 +1,157 @@
+// 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 <asm/sections.h>
+#include <asm/mmu_context.h>
+#include <asm/pgalloc.h>
+
+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_low_pfn = PFN_UP(memblock_end_of_REG0());
+ max_pfn = PFN_DOWN(memblock_end_of_DRAM());
+
+ 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 - CONFIG_RAM_BASE))
+ zone_size[ZONE_NORMAL] = max_pfn - min_low_pfn;
+ else {
+ zone_size[ZONE_NORMAL] = PFN_DOWN(LOWMEM_LIMIT - CONFIG_RAM_BASE);
+ 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 - CONFIG_RAM_BASE);
+ highstart_pfn = min_low_pfn + PFN_DOWN(LOWMEM_LIMIT - CONFIG_RAM_BASE);
+ }
+
+ if (size > 0)
+ zone_size[ZONE_HIGHMEM] = size;
+
+ highend_pfn = max_pfn;
+#endif
+ memblock_set_current_limit(PFN_PHYS(max_low_pfn));
+
+ free_area_init_node(0, zone_size, min_low_pfn, zhole_size);
+}
+
+extern void cpu_dt_probe(void);
+void __init setup_arch(char **cmdline_p)
+{
+ *cmdline_p = boot_command_line;
+
+ console_verbose();
+
+ printk("C-SKY: https://c-sky.github.io\n";);
+
+ 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();
+
+ cpu_dt_probe();
+
+ sparse_init();
+
+#ifdef CONFIG_HIGHMEM
+ kmap_init();
+#endif
+ cache_wbinv_all();
+
+#if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
+ conswitchp = &dummy_con;
+#endif
+}
+
+extern void pre_trap_init(void);
+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();
+
+ /* Setup mmu as coprocessor */
+ select_mmu_cp();
+
+ /*
+ * Setup page-table and enable TLB-hardrefill
+ */
+ flush_tlb_all();
+ pgd_init((unsigned long *)swapper_pg_dir);
+ TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);
+
+ asid_cache(smp_processor_id()) = ASID_FIRST_VERSION;
+
+ /* Setup page mask to 4k */
+ write_mmu_pagemask(0);
+
+#ifdef CONFIG_CSKY_BUILTIN_DTB
+ printk("Use builtin dtb\n");
+ early_init_dt_scan(__dtb_start);
+#else
+ early_init_dt_scan(param);
+#endif
+ printk("Phys. mem: %ldMB\n", (unsigned long) memblock_phys_mem_size()/1024/1024);
+ start_kernel();
+
+ while(1);
+}
+
--
2.7.4