sandbox: implement reset

Up to now the sandbox would shutdown upon a cold reset request. Instead it
should be reset.

In our coding we use static variables like LIST_HEAD(efi_obj_list). A reset
can occur at any time, e.g. via an UEFI binary calling the reset service.
The only safe way to return to an initial state is to relaunch the U-Boot
binary.

The reset implementation uses execv() to relaunch U-Boot.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index 7e474d6..0d8efd8 100644 (file)
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -822,3 +822,9 @@ void *os_find_text_base(void)
 
        return base;
 }
+
+void os_relaunch(char *argv[])
+{
+       execv(argv[0], argv);
+       os_exit(1);
+}

diff --git a/arch/sandbox/cpu/start.c b/arch/sandbox/cpu/start.c
index 58ada13..a03e5aa 100644 (file)
--- a/arch/sandbox/cpu/start.c
+++ b/arch/sandbox/cpu/start.c
@@ -5,6 +5,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <dm/root.h>
 #include <errno.h>
 #include <init.h>
 #include <os.h>
@@ -19,6 +20,8 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+static char **os_argv;
+
 /* Compare two options so that they can be sorted into alphabetical order */
 static int h_compare_opt(const void *p1, const void *p2)
 {
@@ -403,12 +406,35 @@ void state_show(struct sandbox_state *state)
        printf("\n");
 }
 
+void sandbox_reset(void)
+{
+       /* Do this here while it still has an effect */
+       os_fd_restore();
+       if (state_uninit())
+               os_exit(2);
+
+       if (dm_uninit())
+               os_exit(2);
+
+       /* Restart U-Boot */
+       os_relaunch(os_argv);
+}
+
 int main(int argc, char *argv[])
 {
        struct sandbox_state *state;
        gd_t data;
        int ret;
 
+       /*
+        * Copy argv[] so that we can pass the arguments in the original
+        * sequence when resetting the sandbox.
+        */
+       os_argv = calloc(argc + 1, sizeof(char *));
+       if (!os_argv)
+               os_exit(1);
+       memcpy(os_argv, argv, sizeof(char *) * (argc + 1));
+
        memset(&data, '\0', sizeof(data));
        gd = &data;
        gd->arch.text_base = os_find_text_base();

diff --git a/arch/sandbox/cpu/state.c b/arch/sandbox/cpu/state.c
index 34b6fff..59f37fa 100644 (file)
--- a/arch/sandbox/cpu/state.c
+++ b/arch/sandbox/cpu/state.c
@@ -358,6 +358,7 @@ void state_reset_for_test(struct sandbox_state *state)
        /* No reset yet, so mark it as such. Always allow power reset */
        state->last_sysreset = SYSRESET_COUNT;
        state->sysreset_allowed[SYSRESET_POWER_OFF] = true;
+       state->sysreset_allowed[SYSRESET_COLD] = true;
        state->allow_memio = false;
 
        memset(&state->wdt, '\0', sizeof(state->wdt));

diff --git a/arch/sandbox/include/asm/u-boot-sandbox.h b/arch/sandbox/include/asm/u-boot-sandbox.h
index 798d003..73b1897 100644 (file)
--- a/arch/sandbox/include/asm/u-boot-sandbox.h
+++ b/arch/sandbox/include/asm/u-boot-sandbox.h
@@ -84,6 +84,16 @@ void sandbox_set_enable_pci_map(int enable);
  */
 int sandbox_read_fdt_from_file(void);
 
+/**
+ * sandbox_reset() - reset sandbox
+ *
+ * This functions implements the cold reboot of the sandbox. It relaunches the
+ * U-Boot binary with the same command line parameters as the original call.
+ * The PID of the process stays the same. All file descriptors that have not
+ * been opened with O_CLOEXEC stay open including stdin, stdout, stderr.
+ */
+void sandbox_reset(void);
+
 /* Exit sandbox (quit U-Boot) */
 void sandbox_exit(void);
 

diff --git a/drivers/sysreset/sysreset_sandbox.c b/drivers/sysreset/sysreset_sandbox.c
index 71cabd1..7026a48 100644 (file)
--- a/drivers/sysreset/sysreset_sandbox.c
+++ b/drivers/sysreset/sysreset_sandbox.c
@@ -56,6 +56,9 @@ static int sandbox_sysreset_request(struct udevice *dev, enum sysreset_t type)
        switch (type) {
        case SYSRESET_COLD:
                state->last_sysreset = type;
+               if (!state->sysreset_allowed[type])
+                       return -EACCES;
+               sandbox_reset();
                break;
        case SYSRESET_POWER_OFF:
                state->last_sysreset = type;

diff --git a/include/os.h b/include/os.h
index 1874ae6..88dfb71 100644 (file)
--- a/include/os.h
+++ b/include/os.h
@@ -355,4 +355,19 @@ int os_read_file(const char *name, void **bufp, int *sizep);
  */
 void *os_find_text_base(void);
 
+/**
+ * os_relaunch() - restart the sandbox
+ *
+ * This functions is used to implement the cold reboot of the sand box.
+ * @argv[0] specifies the binary that is started while the calling process
+ * stops immediately. If the new binary cannot be started, the process is
+ * terminated and 1 is set as shell return code.
+ *
+ * The PID of the process stays the same. All file descriptors that have not
+ * been opened with O_CLOEXEC stay open including stdin, stdout, stderr.
+ *
+ * @argv:      NULL terminated list of command line parameters
+ */
+void os_relaunch(char *argv[]);
+
 #endif