riscv: cpu: Add nx25 to support RISC-V

Add Andes nx25 cpu core (called AndesStar V5) to support RISC-V arch

Verifications:
1. startup and relocation ok.
2. boot from rom or ram both ok.
2. timer driver ok.
3. uart driver ok
4. mmc driver ok
5. spi driver ok.
6. 32/64 bit both ok.

Detail verification message please see doc/README.ae250.

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>

diff --git a/arch/riscv/cpu/nx25/Makefile b/arch/riscv/cpu/nx25/Makefile
new file mode 100644 (file)
index 0000000..5fcf100
--- /dev/null
+++ b/arch/riscv/cpu/nx25/Makefile
@@ -0,0 +1,10 @@
+#
+# Copyright (C) 2017 Andes Technology Corporation
+# Rick Chen, Andes Technology Corporation <rick@andestech.com>
+#
+# SPDX-License-Identifier:     GPL-2.0+
+#
+
+extra-y        = start.o
+
+obj-y  := cpu.o

diff --git a/arch/riscv/cpu/nx25/cpu.c b/arch/riscv/cpu/nx25/cpu.c
new file mode 100644 (file)
index 0000000..5478f4f
--- /dev/null
+++ b/arch/riscv/cpu/nx25/cpu.c
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2017 Andes Technology Corporation
+ * Rick Chen, Andes Technology Corporation <rick@andestech.com>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+/* CPU specific code */
+#include <common.h>
+#include <command.h>
+#include <watchdog.h>
+#include <asm/cache.h>
+
+/*
+ * cleanup_before_linux() is called just before we call linux
+ * it prepares the processor for linux
+ *
+ * we disable interrupt and caches.
+ */
+int cleanup_before_linux(void)
+{
+       disable_interrupts();
+
+       /* turn off I/D-cache */
+
+       return 0;
+}
+
+int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+       disable_interrupts();
+       panic("nx25-ae250 wdt not support yet.\n");
+}

diff --git a/arch/riscv/cpu/nx25/start.S b/arch/riscv/cpu/nx25/start.S
new file mode 100644 (file)
index 0000000..6a07663
--- /dev/null
+++ b/arch/riscv/cpu/nx25/start.S
@@ -0,0 +1,291 @@
+/*
+ * Startup Code for RISC-V Core
+ *
+ * Copyright (c) 2017 Microsemi Corporation.
+ * Copyright (c) 2017 Padmarao Begari <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 <asm-offsets.h>
+#include <config.h>
+#include <common.h>
+#include <elf.h>
+#include <asm/encoding.h>
+
+#ifdef CONFIG_32BIT
+#define LREG                   lw
+#define SREG                   sw
+#define REGBYTES               4
+#define RELOC_TYPE             R_RISCV_32
+#define SYM_INDEX              0x8
+#define SYM_SIZE               0x10
+#else
+#define LREG                   ld
+#define SREG                   sd
+#define REGBYTES               8
+#define RELOC_TYPE             R_RISCV_64
+#define SYM_INDEX              0x20
+#define SYM_SIZE               0x18
+#endif
+
+.section      .text
+.globl _start
+_start:
+       j handle_reset
+
+nmi_vector:
+       j nmi_vector
+
+trap_vector:
+       j trap_entry
+
+.global trap_entry
+handle_reset:
+       la t0, trap_entry
+       csrw mtvec, t0
+       csrwi mstatus, 0
+       csrwi mie, 0
+
+/*
+ * Do CPU critical regs init only at reboot,
+ * not when booting from ram
+ */
+#ifdef CONFIG_INIT_CRITICAL
+       jal cpu_init_crit       /* Do CPU critical regs init */
+#endif
+
+/*
+ * Set stackpointer in internal/ex RAM to call board_init_f
+ */
+call_board_init_f:
+       li  t0, -16
+       li  t1, CONFIG_SYS_INIT_SP_ADDR
+       and sp, t1, t0  /* force 16 byte alignment */
+
+#ifdef CONFIG_DEBUG_UART
+       jal     debug_uart_init
+#endif
+
+call_board_init_f_0:
+       mv      a0, sp
+       jal     board_init_f_alloc_reserve
+       mv      sp, a0
+       jal     board_init_f_init_reserve
+
+       mv  a0, zero    /* a0 <-- boot_flags = 0 */
+       la t5, board_init_f
+       jr t5           /* jump to board_init_f() */
+
+/*
+ * void relocate_code (addr_sp, gd, addr_moni)
+ *
+ * This "function" does not return, instead it continues in RAM
+ * after relocating the monitor code.
+ *
+ */
+.globl relocate_code
+relocate_code:
+       mv  s2, a0      /* save addr_sp */
+       mv  s3, a1      /* save addr of gd */
+       mv  s4, a2      /* save addr of destination */
+
+/*
+ *Set up the stack
+ */
+stack_setup:
+       mv sp, s2
+       la t0, _start
+       sub t6, s4, t0  /* t6 <- relocation offset */
+       beq t0, s4, clear_bss   /* skip relocation */
+
+       mv t1, s4       /* t1 <- scratch for copy_loop */
+       la t3, __bss_start
+       sub t3, t3, t0  /* t3 <- __bss_start_ofs */
+       add t2, t0, t3  /* t2 <- source end address */
+
+copy_loop:
+       LREG t5, 0(t0)
+       addi t0, t0, REGBYTES
+       SREG t5, 0(t1)
+       addi t1, t1, REGBYTES
+       blt t0, t2, copy_loop
+
+/*
+ * Update dynamic relocations after board_init_f
+ */
+fix_rela_dyn:
+       la  t1, __rel_dyn_start
+       la  t2, __rel_dyn_end
+       beq t1, t2, clear_bss
+       add t1, t1, t6                  /* t1 <- rela_dyn_start in RAM */
+       add t2, t2, t6                  /* t2 <- rela_dyn_end in RAM */
+
+/*
+ * skip first reserved entry: address, type, addend
+ */
+       bne t1, t2, 7f
+
+6:
+       LREG  t5, -(REGBYTES*2)(t1)     /* t5 <-- relocation info:type */
+       li  t3, R_RISCV_RELATIVE        /* reloc type R_RISCV_RELATIVE */
+       bne t5, t3, 8f                  /* skip non-RISCV_RELOC entries */
+       LREG t3, -(REGBYTES*3)(t1)
+       LREG t5, -(REGBYTES)(t1)        /* t5 <-- addend */
+       add t5, t5, t6                  /* t5 <-- location to fix up in RAM */
+       add t3, t3, t6                  /* t3 <-- location to fix up in RAM */
+       SREG t5, 0(t3)
+7:
+       addi t1, t1, (REGBYTES*3)
+       ble t1, t2, 6b
+
+8:
+       la  t4, __dyn_sym_start
+       add t4, t4, t6
+
+9:
+       LREG  t5, -(REGBYTES*2)(t1)     /* t5 <-- relocation info:type */
+       srli t0, t5, SYM_INDEX          /* t0 <--- sym table index */
+       andi t5, t5, 0xFF               /* t5 <--- relocation type */
+       li  t3, RELOC_TYPE
+       bne t5, t3, 10f                 /* skip non-addned entries */
+
+       LREG t3, -(REGBYTES*3)(t1)
+       li t5, SYM_SIZE
+       mul t0, t0, t5
+       add s1, t4, t0
+       LREG t5, REGBYTES(s1)
+       add t5, t5, t6                  /* t5 <-- location to fix up in RAM */
+       add t3, t3, t6                  /* t3 <-- location to fix up in RAM */
+       SREG t5, 0(t3)
+10:
+       addi t1, t1, (REGBYTES*3)
+       ble t1, t2, 9b
+
+/*
+ * trap update
+*/
+       la t0, trap_entry
+       add t0, t0, t6
+       csrw mtvec, t0
+
+clear_bss:
+       la t0, __bss_start              /* t0 <- rel __bss_start in FLASH */
+       add t0, t0, t6                  /* t0 <- rel __bss_start in RAM */
+       la t1, __bss_end                /* t1 <- rel __bss_end in FLASH */
+       add t1, t1, t6                  /* t1 <- rel __bss_end in RAM */
+       li t2, 0x00000000               /* clear */
+       beq t0, t1, call_board_init_r
+
+clbss_l:
+       SREG t2, 0(t0)                  /* clear loop... */
+       addi t0, t0, REGBYTES
+       bne t0, t1, clbss_l
+
+/*
+ * We are done. Do not return, instead branch to second part of board
+ * initialization, now running from RAM.
+ */
+call_board_init_r:
+       la t0, board_init_r
+       mv t4, t0                       /* offset of board_init_r() */
+       add t4, t4, t6                  /* real address of board_init_r() */
+/*
+ * setup parameters for board_init_r
+ */
+       mv a0, s3                       /* gd_t */
+       mv a1, s4                       /* dest_addr */
+
+/*
+ * jump to it ...
+ */
+       jr t4                           /* jump to board_init_r() */
+
+/*
+ * trap entry
+ */
+trap_entry:
+       addi sp, sp, -32*REGBYTES
+       SREG x1, 1*REGBYTES(sp)
+       SREG x2, 2*REGBYTES(sp)
+       SREG x3, 3*REGBYTES(sp)
+       SREG x4, 4*REGBYTES(sp)
+       SREG x5, 5*REGBYTES(sp)
+       SREG x6, 6*REGBYTES(sp)
+       SREG x7, 7*REGBYTES(sp)
+       SREG x8, 8*REGBYTES(sp)
+       SREG x9, 9*REGBYTES(sp)
+       SREG x10, 10*REGBYTES(sp)
+       SREG x11, 11*REGBYTES(sp)
+       SREG x12, 12*REGBYTES(sp)
+       SREG x13, 13*REGBYTES(sp)
+       SREG x14, 14*REGBYTES(sp)
+       SREG x15, 15*REGBYTES(sp)
+       SREG x16, 16*REGBYTES(sp)
+       SREG x17, 17*REGBYTES(sp)
+       SREG x18, 18*REGBYTES(sp)
+       SREG x19, 19*REGBYTES(sp)
+       SREG x20, 20*REGBYTES(sp)
+       SREG x21, 21*REGBYTES(sp)
+       SREG x22, 22*REGBYTES(sp)
+       SREG x23, 23*REGBYTES(sp)
+       SREG x24, 24*REGBYTES(sp)
+       SREG x25, 25*REGBYTES(sp)
+       SREG x26, 26*REGBYTES(sp)
+       SREG x27, 27*REGBYTES(sp)
+       SREG x28, 28*REGBYTES(sp)
+       SREG x29, 29*REGBYTES(sp)
+       SREG x30, 30*REGBYTES(sp)
+       SREG x31, 31*REGBYTES(sp)
+       csrr a0, mcause
+       csrr a1, mepc
+       mv a2, sp
+       jal handle_trap
+       csrw mepc, a0
+
+/*
+ * Remain in M-mode after mret
+ */
+       li t0, MSTATUS_MPP
+       csrs mstatus, t0
+       LREG x1, 1*REGBYTES(sp)
+       LREG x2, 2*REGBYTES(sp)
+       LREG x3, 3*REGBYTES(sp)
+       LREG x4, 4*REGBYTES(sp)
+       LREG x5, 5*REGBYTES(sp)
+       LREG x6, 6*REGBYTES(sp)
+       LREG x7, 7*REGBYTES(sp)
+       LREG x8, 8*REGBYTES(sp)
+       LREG x9, 9*REGBYTES(sp)
+       LREG x10, 10*REGBYTES(sp)
+       LREG x11, 11*REGBYTES(sp)
+       LREG x12, 12*REGBYTES(sp)
+       LREG x13, 13*REGBYTES(sp)
+       LREG x14, 14*REGBYTES(sp)
+       LREG x15, 15*REGBYTES(sp)
+       LREG x16, 16*REGBYTES(sp)
+       LREG x17, 17*REGBYTES(sp)
+       LREG x18, 18*REGBYTES(sp)
+       LREG x19, 19*REGBYTES(sp)
+       LREG x20, 20*REGBYTES(sp)
+       LREG x21, 21*REGBYTES(sp)
+       LREG x22, 22*REGBYTES(sp)
+       LREG x23, 23*REGBYTES(sp)
+       LREG x24, 24*REGBYTES(sp)
+       LREG x25, 25*REGBYTES(sp)
+       LREG x26, 26*REGBYTES(sp)
+       LREG x27, 27*REGBYTES(sp)
+       LREG x28, 28*REGBYTES(sp)
+       LREG x29, 29*REGBYTES(sp)
+       LREG x30, 30*REGBYTES(sp)
+       LREG x31, 31*REGBYTES(sp)
+       addi sp, sp, 32*REGBYTES
+       mret
+
+#ifdef CONFIG_INIT_CRITICAL
+cpu_init_crit:
+    ret
+#endif

diff --git a/arch/riscv/cpu/nx25/u-boot.lds b/arch/riscv/cpu/nx25/u-boot.lds
new file mode 100644 (file)
index 0000000..936fd77
--- /dev/null
+++ b/arch/riscv/cpu/nx25/u-boot.lds
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) 2017 Andes Technology Corporation
+ * Rick Chen, Andes Technology Corporation <rick@andestech.com>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+OUTPUT_ARCH("riscv")
+ENTRY(_start)
+
+SECTIONS
+{
+       . = ALIGN(4);
+       .text :
+       {
+               arch/riscv/cpu/nx25/start.o     (.text)
+               *(.text)
+       }
+
+       . = ALIGN(4);
+       .rodata : { *(SORT_BY_ALIGNMENT(SORT_BY_NAME(.rodata*))) }
+
+       . = ALIGN(4);
+       .data : {
+               __global_pointer$ = . + 0x800;
+               *(.data*)
+       }
+       . = ALIGN(4);
+
+       .got : {
+          __got_start = .;
+          *(.got.plt) *(.got)
+          __got_end = .;
+    }
+
+       . = ALIGN(4);
+
+       .u_boot_list : {
+               KEEP(*(SORT(.u_boot_list*)));
+       }
+
+    . = ALIGN(4);
+
+    /DISCARD/ : { *(.rela.plt*) }
+    .rela.dyn : {
+        __rel_dyn_start = .;
+        *(.rela*)
+        __rel_dyn_end = .;
+    }
+
+    . = ALIGN(4);
+
+    .dynsym : {
+        __dyn_sym_start = .;
+        *(.dynsym)
+        __dyn_sym_end = .;
+    }
+
+    . = ALIGN(4);
+
+       _end = .;
+
+       .bss : {
+        __bss_start = .;
+        *(.bss)
+               . = ALIGN(4);
+               __bss_end = .;
+       }
+
+}