riscv: nx25: lib: Add relative lib funcs to support RISC-V

Add makefile, interrupts.c and boot.c,... functions
to support RISC-V arch.

Signed-off-by: Rick Chen <rick@andestech.com>
Signed-off-by: Rick Chen <rickchen36@gmail.com>
Signed-off-by: Greentime Hu <green.hu@gmail.com>
Cc: Padmarao Begari <Padmarao.Begari@microsemi.com>

arch/riscv/lib/Makefile

+#
+# (C) Copyright 2000-2006
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+#
+# Copyright (C) 2017 Andes Technology Corporation
+# Rick Chen, Andes Technology Corporation <rick@andestech.com>
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-$(CONFIG_CMD_BOOTM) += bootm.o
+obj-$(CONFIG_CMD_GO) += boot.o
+obj-y	+= cache.o
+obj-y	+= interrupts.o

arch/riscv/lib/boot.c

+/*
+ * Copyright (C) 2017 Andes Technology Corporation
+ * Rick Chen, Andes Technology Corporation <rick@andestech.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <command.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+unsigned long do_go_exec(ulong (*entry)(int, char * const []),
+			 int argc, char * const argv[])
+{
+	cleanup_before_linux();
+
+	return entry(argc, argv);
+}

arch/riscv/lib/bootm.c

+/*
+ * Copyright (C) 2011 Andes Technology Corporation
+ * Shawn Lin, Andes Technology Corporation <nobuhiro@andestech.com>
+ * Macpaul Lin, Andes Technology Corporation <macpaul@andestech.com>
+ * Rick Chen, Andes Technology Corporation <rick@andestech.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <command.h>
+#include <image.h>
+#include <u-boot/zlib.h>
+#include <asm/byteorder.h>
+#include <asm/bootm.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int arch_fixup_fdt(void *blob)
+{
+	return 0;
+}
+
+#if defined(CONFIG_SETUP_MEMORY_TAGS) || \
+	defined(CONFIG_CMDLINE_TAG) || \
+	defined(CONFIG_INITRD_TAG) || \
+	defined(CONFIG_SERIAL_TAG) || \
+	defined(CONFIG_REVISION_TAG)
+static void setup_start_tag(bd_t *bd);
+
+# ifdef CONFIG_SETUP_MEMORY_TAGS
+static void setup_memory_tags(bd_t *bd);
+# endif
+static void setup_commandline_tag(bd_t *bd, char *commandline);
+
+# ifdef CONFIG_INITRD_TAG
+static void setup_initrd_tag(bd_t *bd, ulong initrd_start, ulong initrd_end);
+# endif
+static void setup_end_tag(bd_t *bd);
+
+static struct tag *params;
+#endif /* CONFIG_SETUP_MEMORY_TAGS || CONFIG_CMDLINE_TAG || CONFIG_INITRD_TAG */
+
+int do_bootm_linux(int flag, int argc, char *argv[], bootm_headers_t *images)
+{
+	bd_t	*bd = gd->bd;
+	char	*s;
+	int	machid = bd->bi_arch_number;
+	void	(*theKernel)(int zero, int arch, uint params);
+
+#ifdef CONFIG_CMDLINE_TAG
+	char *commandline = env_get("bootargs");
+#endif
+
+	/*
+	 * allow the PREP bootm subcommand, it is required for bootm to work
+	 */
+	if (flag & BOOTM_STATE_OS_PREP)
+		return 0;
+
+	if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
+		return 1;
+
+	theKernel = (void (*)(int, int, uint))images->ep;
+
+	s = env_get("machid");
+	if (s) {
+		machid = simple_strtoul(s, NULL, 16);
+		printf("Using machid 0x%x from environment\n", machid);
+	}
+
+	bootstage_mark(BOOTSTAGE_ID_RUN_OS);
+
+	debug("## Transferring control to Linux (at address %08lx) ...\n",
+	       (ulong)theKernel);
+
+	if (IMAGE_ENABLE_OF_LIBFDT && images->ft_len) {
+#ifdef CONFIG_OF_LIBFDT
+		debug("using: FDT\n");
+		if (image_setup_linux(images)) {
+			printf("FDT creation failed! hanging...");
+			hang();
+		}
+#endif
+	} else if (BOOTM_ENABLE_TAGS) {
+#if defined(CONFIG_SETUP_MEMORY_TAGS) || \
+	defined(CONFIG_CMDLINE_TAG) || \
+	defined(CONFIG_INITRD_TAG) || \
+	defined(CONFIG_SERIAL_TAG) || \
+	defined(CONFIG_REVISION_TAG)
+	setup_start_tag(bd);
+#ifdef CONFIG_SERIAL_TAG
+	setup_serial_tag(&params);
+#endif
+#ifdef CONFIG_REVISION_TAG
+	setup_revision_tag(&params);
+#endif
+#ifdef CONFIG_SETUP_MEMORY_TAGS
+	setup_memory_tags(bd);
+#endif
+#ifdef CONFIG_CMDLINE_TAG
+	setup_commandline_tag(bd, commandline);
+#endif
+#ifdef CONFIG_INITRD_TAG
+	if (images->rd_start && images->rd_end)
+		setup_initrd_tag(bd, images->rd_start, images->rd_end);
+#endif
+	setup_end_tag(bd);
+#endif
+
+	/* we assume that the kernel is in place */
+	printf("\nStarting kernel ...\n\n");
+
+#ifdef CONFIG_USB_DEVICE
+	{
+		extern void udc_disconnect(void);
+		udc_disconnect();
+	}
+#endif
+	}
+	cleanup_before_linux();
+	if (IMAGE_ENABLE_OF_LIBFDT && images->ft_len)
+		theKernel(0, machid, (unsigned long)images->ft_addr);
+	else
+	theKernel(0, machid, bd->bi_boot_params);
+	/* does not return */
+
+	return 1;
+}
+
+#if defined(CONFIG_SETUP_MEMORY_TAGS) || \
+	defined(CONFIG_CMDLINE_TAG) || \
+	defined(CONFIG_INITRD_TAG) || \
+	defined(CONFIG_SERIAL_TAG) || \
+	defined(CONFIG_REVISION_TAG)
+static void setup_start_tag(bd_t *bd)
+{
+	params = (struct tag *)bd->bi_boot_params;
+
+	params->hdr.tag = ATAG_CORE;
+	params->hdr.size = tag_size(tag_core);
+
+	params->u.core.flags = 0;
+	params->u.core.pagesize = 0;
+	params->u.core.rootdev = 0;
+
+	params = tag_next(params);
+}
+
+#ifdef CONFIG_SETUP_MEMORY_TAGS
+static void setup_memory_tags(bd_t *bd)
+{
+	int i;
+
+	for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
+		params->hdr.tag = ATAG_MEM;
+		params->hdr.size = tag_size(tag_mem32);
+
+		params->u.mem.start = bd->bi_dram[i].start;
+		params->u.mem.size = bd->bi_dram[i].size;
+
+		params = tag_next(params);
+	}
+}
+#endif /* CONFIG_SETUP_MEMORY_TAGS */
+
+static void setup_commandline_tag(bd_t *bd, char *commandline)
+{
+	char *p;
+
+	if (!commandline)
+		return;
+
+	/* eat leading white space */
+	for (p = commandline; *p == ' '; p++)
+		;
+
+	/* skip non-existent command lines so the kernel will still
+	 * use its default command line.
+	 */
+	if (*p == '\0')
+		return;
+
+	params->hdr.tag = ATAG_CMDLINE;
+	params->hdr.size =
+		(sizeof(struct tag_header) + strlen(p) + 1 + 4) >> 2;
+
+	strcpy(params->u.cmdline.cmdline, p)
+		;
+
+	params = tag_next(params);
+}
+
+#ifdef CONFIG_INITRD_TAG
+static void setup_initrd_tag(bd_t *bd, ulong initrd_start, ulong initrd_end)
+{
+	/* an ATAG_INITRD node tells the kernel where the compressed
+	 * ramdisk can be found. ATAG_RDIMG is a better name, actually.
+	 */
+	params->hdr.tag = ATAG_INITRD2;
+	params->hdr.size = tag_size(tag_initrd);
+
+	params->u.initrd.start = initrd_start;
+	params->u.initrd.size = initrd_end - initrd_start;
+
+	params = tag_next(params);
+}
+#endif /* CONFIG_INITRD_TAG */
+
+#ifdef CONFIG_SERIAL_TAG
+void setup_serial_tag(struct tag **tmp)
+{
+	struct tag *params;
+	struct tag_serialnr serialnr;
+	void get_board_serial(struct tag_serialnr *serialnr);
+
+	params = *tmp;
+	get_board_serial(&serialnr);
+	params->hdr.tag = ATAG_SERIAL;
+	params->hdr.size = tag_size(tag_serialnr);
+	params->u.serialnr.low = serialnr.low;
+	params->u.serialnr.high = serialnr.high;
+	params = tag_next(params);
+	*tmp = params;
+}
+#endif
+
+#ifdef CONFIG_REVISION_TAG
+void setup_revision_tag(struct tag **in_params)
+{
+	u32 rev;
+	u32 get_board_rev(void);
+
+	rev = get_board_rev();
+	params->hdr.tag = ATAG_REVISION;
+	params->hdr.size = tag_size(tag_revision);
+	params->u.revision.rev = rev;
+	params = tag_next(params);
+}
+#endif  /* CONFIG_REVISION_TAG */
+
+static void setup_end_tag(bd_t *bd)
+{
+	params->hdr.tag = ATAG_NONE;
+	params->hdr.size = 0;
+}
+
+#endif /* CONFIG_SETUP_MEMORY_TAGS || CONFIG_CMDLINE_TAG || CONFIG_INITRD_TAG */

arch/riscv/lib/cache.c

+/*
+ * Copyright (C) 2017 Andes Technology Corporation
+ * Rick Chen, Andes Technology Corporation <rick@andestech.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+
+void flush_dcache_range(unsigned long start, unsigned long end)
+{
+}
+
+void invalidate_icache_range(unsigned long start, unsigned long end)
+{
+}
+
+void invalidate_dcache_range(unsigned long start, unsigned long end)
+{
+}
+
+void flush_cache(unsigned long addr, unsigned long size)
+{
+}
+
+void icache_enable(void)
+{
+}
+
+void icache_disable(void)
+{
+}
+
+int icache_status(void)
+{
+	return 0;
+}
+
+void dcache_enable(void)
+{
+}
+
+void dcache_disable(void)
+{
+}
+
+int dcache_status(void)
+{
+	return 0;
+}

arch/riscv/lib/interrupts.c

+/*
+ * Copyright (c) 2016-17 Microsemi Corporation.
+ * Padmarao Begari, Microsemi Corporation <padmarao.begari@microsemi.com>
+ *
+ * Copyright (C) 2017 Andes Technology Corporation
+ * Rick Chen, Andes Technology Corporation <rick@andestech.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/ptrace.h>
+#include <asm/system.h>
+#include <asm/encoding.h>
+
+static void _exit_trap(int code, uint epc, struct pt_regs *regs);
+
+int interrupt_init(void)
+{
+	return 0;
+}
+
+/*
+ * enable interrupts
+ */
+void enable_interrupts(void)
+{
+}
+
+/*
+ * disable interrupts
+ */
+int disable_interrupts(void)
+{
+	return 0;
+}
+
+uint handle_trap(uint mcause, uint epc, struct pt_regs *regs)
+{
+	uint is_int;
+
+	is_int = (mcause & MCAUSE_INT);
+	if ((is_int) && ((mcause & MCAUSE_CAUSE)  == IRQ_M_EXT))
+		external_interrupt(0);	/* handle_m_ext_interrupt */
+	else if ((is_int) && ((mcause & MCAUSE_CAUSE)  == IRQ_M_TIMER))
+		timer_interrupt(0);	/* handle_m_timer_interrupt */
+	else
+		_exit_trap(mcause, epc, regs);
+
+	return epc;
+}
+
+/*
+ *Entry Point for PLIC Interrupt Handler
+ */
+__attribute__((weak)) void external_interrupt(struct pt_regs *regs)
+{
+}
+
+__attribute__((weak)) void timer_interrupt(struct pt_regs *regs)
+{
+}
+
+static void _exit_trap(int code, uint epc, struct pt_regs *regs)
+{
+	static const char *exception_code[] = {
+		"Instruction address misaligned",
+		"Instruction access fault",
+		"Illegal instruction",
+		"Breakpoint",
+		"Load address misaligned"
+	};
+
+	printf("exception code: %d , %s , epc %08x , ra %08lx\n",
+		code, exception_code[code], epc, regs->ra);
+}