nixos-riscv/uboot-exception-extras.patch

diff --git a/cmd/riscv/exception.c b/cmd/riscv/exception.c
index f38f454a0b..9de4effe47 100644
--- a/cmd/riscv/exception.c
+++ b/cmd/riscv/exception.c
@@ -56,6 +56,40 @@ static int do_undefined(struct cmd_tbl *cmdtp, int flag, int argc,
 	return CMD_RET_FAILURE;
 }
 
+static int do_sregs(struct cmd_tbl *cmdtp, int flag, int argc,
+			char *const argv[])
+{
+	ulong stvec, sie, sip, sstatus;
+
+	asm volatile ("fence");
+	asm volatile ("csrr %0, stvec" : "=r"(stvec) : );
+	asm volatile ("csrr %0, sie" : "=r"(sie) : );
+	asm volatile ("csrr %0, sip" : "=r"(sip) : );
+	asm volatile ("csrr %0, sstatus" : "=r"(sstatus) : );
+
+	printf("stvec   : 0x%016lx\n", stvec);
+	printf("sie     : 0x%016lx\n", sie);
+	printf("sip     : 0x%016lx\n", sip);
+	printf("sstatus : 0x%016lx\n", sstatus);
+
+	return CMD_RET_SUCCESS;
+}
+
+static int do_enable(struct cmd_tbl *cmdtp, int flag, int argc,
+			char *const argv[])
+{
+	ulong which = SIE_SSIE | SIE_SEIE | SIE_STIE;
+
+	asm volatile (
+		"csrsi sstatus, 2\n" /* Enable SIE */
+		"csrs sie, %0\n" /* Enable selected interrupts */
+		: /* no output */
+		: "r" (which)
+	);
+
+	return CMD_RET_SUCCESS;
+}
+
 static struct cmd_tbl cmd_sub[] = {
 	U_BOOT_CMD_MKENT(compressed, CONFIG_SYS_MAXARGS, 1, do_compressed,
 			 "", ""),
@@ -67,6 +101,10 @@ static struct cmd_tbl cmd_sub[] = {
 			 "", ""),
 	U_BOOT_CMD_MKENT(undefined, CONFIG_SYS_MAXARGS, 1, do_undefined,
 			 "", ""),
+	U_BOOT_CMD_MKENT(sregs, CONFIG_SYS_MAXARGS, 1, do_sregs,
+			 "", ""),
+	U_BOOT_CMD_MKENT(enable, CONFIG_SYS_MAXARGS, 1, do_enable,
+			 "", ""),
 };
 
 static char exception_help_text[] =
@@ -77,6 +115,8 @@ static char exception_help_text[] =
 	"  ialign16   - 16 bit aligned instruction\n"
 	"  undefined  - illegal instruction\n"
 	"  unaligned  - load address misaligned\n"
+	"  sregs      - print supervisor registers\n"
+	"  enable     - enable supervisor interrupts\n"
 	;
 
 #include <exception.h>