Merge git://git.denx.de/u-boot-riscv

1. Improve cache implementation.
2. Fix and improve standalone applications

arch/riscv/config.mk

@@ -23,8 +23,7 @@ PLATFORM_LDFLAGS	+= -m $(64bit-emul)
 EFI_LDS			:= elf_riscv64_efi.lds
 endif
 
-CONFIG_STANDALONE_LOAD_ADDR = 0x00000000
-LDFLAGS_STANDALONE += -T $(srctree)/examples/standalone/riscv.lds
+CONFIG_STANDALONE_LOAD_ADDR ?= 0x00000000
 
 PLATFORM_CPPFLAGS	+= -ffixed-gp -fpic
 PLATFORM_RELFLAGS	+= -fno-common -gdwarf-2 -ffunction-sections \

arch/riscv/cpu/ax25/cache.c

@@ -6,6 +6,28 @@
 
 #include <common.h>
 
+void flush_dcache_all(void)
+{
+	/*
+	 * Andes' AX25 does not have a coherence agent. U-Boot must use data
+	 * cache flush and invalidate functions to keep data in the system
+	 * coherent.
+	 * The implementation of the fence instruction in the AX25 flushes the
+	 * data cache and is used for this purpose.
+	 */
+	asm volatile ("fence" ::: "memory");
+}
+
+void flush_dcache_range(unsigned long start, unsigned long end)
+{
+	flush_dcache_all();
+}
+
+void invalidate_dcache_range(unsigned long start, unsigned long end)
+{
+	flush_dcache_all();
+}
+
 void icache_enable(void)
 {
 #ifndef CONFIG_SYS_ICACHE_OFF

arch/riscv/lib/cache.c

@@ -11,13 +11,12 @@ void invalidate_icache_all(void)
 	asm volatile ("fence.i" ::: "memory");
 }
 
-void flush_dcache_all(void)
+__weak void flush_dcache_all(void)
 {
-	asm volatile ("fence" :::"memory");
 }
-void flush_dcache_range(unsigned long start, unsigned long end)
+
+__weak void flush_dcache_range(unsigned long start, unsigned long end)
 {
-	flush_dcache_all();
 }
 
 void invalidate_icache_range(unsigned long start, unsigned long end)
@@ -29,9 +28,8 @@ void invalidate_icache_range(unsigned long start, unsigned long end)
 	invalidate_icache_all();
 }
 
-void invalidate_dcache_range(unsigned long start, unsigned long end)
+__weak void invalidate_dcache_range(unsigned long start, unsigned long end)
 {
-	flush_dcache_all();
 }
 
 void cache_flush(void)
@@ -42,8 +40,8 @@ void cache_flush(void)
 
 void flush_cache(unsigned long addr, unsigned long size)
 {
-	invalidate_icache_all();
-	flush_dcache_all();
+	invalidate_icache_range(addr, addr + size);
+	flush_dcache_range(addr, addr + size);
 }
 
 __weak void icache_enable(void)

arch/riscv/lib/interrupts.c

@@ -37,7 +37,8 @@ static void _exit_trap(ulong code, ulong epc, struct pt_regs *regs)
 		printf("exception code: %ld , %s , epc %lx , ra %lx\n",
 		       code, exception_code[code], epc, regs->ra);
 	} else {
-		printf("Reserved\n");
+		printf("reserved exception code: %ld , epc %lx , ra %lx\n",
+		       code, epc, regs->ra);
 	}
 
 	hang();

examples/standalone/riscv.lds

@@ -1,40 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0+ */
-/*
- * Copyright (C) 2017 Andes Technology Corporation
- * Rick Chen, Andes Technology Corporation <rick@andestech.com>
- */
-
-OUTPUT_ARCH(riscv)
-ENTRY(_start)
-SECTIONS
-{
-    . = ALIGN(4);
-    .text :
-    {
-        *(.text)
-    }
-
-    . = ALIGN(4);
-    .data : {
-			__global_pointer$ = . + 0x800;
-			*(.data)
-		}
-
-    . = ALIGN(4);
-
-    .got : {
-        __got_start = .;
-        *(.got)
-        __got_end = .;
-    }
-
-     . = ALIGN(4);
-    __bss_start = .;
-    .bss : { *(.bss) }
-    __bss_end = .;
-
-    . = ALIGN(4);
-    .rela.text : { *(.rela.text .rela.text.* .rela.gnu.linkonce.t.*) }
-
-    _end = .;
-}

examples/standalone/stubs.c

@@ -174,16 +174,27 @@ gd_t *global_data;
 	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "$r16");
 #elif defined(CONFIG_RISCV)
 /*
- * t7 holds the pointer to the global_data. gp is call clobbered.
+ * gp holds the pointer to the global_data. t0 is call clobbered.
  */
+#ifdef CONFIG_ARCH_RV64I
 #define EXPORT_FUNC(f, a, x, ...)	\
 	asm volatile (			\
 "	.globl " #x "\n"		\
 #x ":\n"				\
-"	lw	x19, %0(gp)\n"		\
-"	lw	x19, %1(x19)\n"		\
-"	jr	x19\n"			\
-	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "x19");
+"	ld	t0, %0(gp)\n"		\
+"	ld	t0, %1(t0)\n"		\
+"	jr	t0\n"			\
+	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t0");
+#else
+#define EXPORT_FUNC(f, a, x, ...)	\
+	asm volatile (			\
+"	.globl " #x "\n"		\
+#x ":\n"				\
+"	lw	t0, %0(gp)\n"		\
+"	lw	t0, %1(t0)\n"		\
+"	jr	t0\n"			\
+	: : "i"(offsetof(gd_t, jt)), "i"(FO(x)) : "t0");
+#endif
 #elif defined(CONFIG_ARC)
 /*
  * r25 holds the pointer to the global_data. r10 is call clobbered.

include/configs/qemu-riscv.h

@@ -17,6 +17,8 @@
 
 #define CONFIG_SYS_BOOTM_LEN		SZ_16M
 
+#define CONFIG_STANDALONE_LOAD_ADDR	0x80200000
+
 /* Environment options */
 #define CONFIG_ENV_SIZE			SZ_4K