risc-v/k230: improvements to support K230 vendor u-boot

Previously we need turn off the PMP locks in K230 vendor u-boot to use
NuttX, this complicates the setup process. This patch supports running
NuttX with original vendor u-boot so that to reduce setup complexity.

It also enables empty NSH prompt string in AMP master config as the apps
side support is ready.

Signed-off-by: Yanfeng Liu <yfliu2008@qq.com>

arch/risc-v/src/k230/k230_hart.c

@@ -127,12 +127,9 @@ static void k230_hart_cleanup(void)
 
 void k230_hart_init(void)
 {
-  #define MISA_VECTOR_BIT   ('V'-'A')
+  /* TODO: when called from sbi_start(), MISA is 0 somehow. */
-  #define MISA_VECTOR_MASK  (1 << MISA_VECTOR_BIT)
 
-  /* When called from sbi_start(), MISA is 0 somehow. */
+  g_big = (READ_CSR(CSR_MISA) & (1 << 21));
-
-  g_big = (READ_CSR(CSR_MISA) & MISA_VECTOR_MASK);
 
   k230_hart_cleanup();
 
@@ -146,6 +143,12 @@ void k230_hart_init(void)
 #ifdef RISCV_PBMT
   SET_CSR(CSR_MENVCFG, MENVCFG_PBMT);
 #endif
+
+#ifdef CONFIG_NUTTSBI
+  /* Some PMP entries might have been locked */
+
+  k230_add_pmp(PMPCFG_A_NAPOT | PMPCFG_RWX_MASK, 0, 1024ul << 30);
+#endif
 }
 
 /****************************************************************************

arch/risc-v/src/k230/k230_hart.h

@@ -22,9 +22,20 @@
 #define __ARCH_RISCV_SRC_K230_K230_HART_H
 
 /****************************************************************************
- * Included Files
+ * Preprocessor Macros
  ****************************************************************************/
 
+/* add PMP entry with (attr, base, size) */
+
+#define k230_add_pmp(a, b, s)   riscv_config_pmp_region( \
+                                  riscv_next_free_pmp_region(), a, b, s)
+
+#define CSR_MSECCFG     0x747
+#define CSR_MSECCFGH    0x757
+
+#define MSECCFG_MML     (1 << 0)
+#define MSECCFG_RLB     (1 << 2)
+
 /****************************************************************************
  * Public functions
  ****************************************************************************/

arch/risc-v/src/k230/k230_userspace.c

@@ -34,6 +34,7 @@
 
 #include "k230_userspace.h"
 #include "riscv_internal.h"
+#include "k230_hart.h"
 
 #ifdef CONFIG_BUILD_PROTECTED
 
@@ -127,8 +128,8 @@ void k230_userspace(void)
 
 static void configure_mpu(void)
 {
-  riscv_config_pmp_region(0, UFLASH_F, UFLASH_START, UFLASH_SIZE);
+  k230_add_pmp(UFLASH_F, UFLASH_START, UFLASH_SIZE);
-  riscv_config_pmp_region(1, USRAM_F, USRAM_START, USRAM_SIZE);
+  k230_add_pmp(USRAM_F, USRAM_START, USRAM_SIZE);
 }
 
 #endif /* CONFIG_BUILD_PROTECTED */

boards/risc-v/k230/canmv230/configs/master/defconfig

@@ -76,7 +76,7 @@ CONFIG_NFILE_DESCRIPTORS_PER_BLOCK=6
 CONFIG_NSH_ARCHINIT=y
 CONFIG_NSH_FILEIOSIZE=512
 CONFIG_NSH_FILE_APPS=y
-CONFIG_NSH_PROMPT_STRING="master> "
+CONFIG_NSH_PROMPT_STRING=""
 CONFIG_NSH_READLINE=y
 CONFIG_NUTTSBI=y
 CONFIG_NUTTSBI_MTIMECMP_BASE=0xf04004000