[Xen-devel] [PATCH v2 17/22] mini-os: add get_cmdline() function

[Juergen Gross <jgross@xxxxxxxx>]

The command line parameters are passed in start_info structure for pv,
but via hvm_start_info for HVMlite. Add a generic function to fill a
local cmdline variable with the command line string.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>
---
 arch/x86/setup.c | 20 ++++++++++++++++++--
 include/kernel.h |  3 +++
 kernel.c         |  1 +
 main.c           |  5 +++--
 4 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/arch/x86/setup.c b/arch/x86/setup.c
index 6645784..13633f0 100644
--- a/arch/x86/setup.c
+++ b/arch/x86/setup.c
@@ -31,6 +31,7 @@
 #include <mini-os/kernel.h>
 #include <xen/xen.h>
 #include <xen/arch-x86/cpuid.h>
+#include <xen/arch-x86/hvm/start_info.h>
 
 /*
  * Shared page for communicating with the hypervisor.
@@ -88,6 +89,13 @@ static inline void sse_init(void) {
 
 #ifdef CONFIG_PARAVIRT
 #define hpc_init()
+
+static void get_cmdline(void *p)
+{
+    start_info_t *si = p;
+
+    strncpy(cmdline, (char *)si->cmd_line, MAX_CMDLINE_SIZE - 1);
+}
 #else
 static void hpc_init(void)
 {
@@ -109,6 +117,14 @@ static void hpc_init(void)
     wrmsrl(ebx, (unsigned long)&hypercall_page);
     barrier();
 }
+
+static void get_cmdline(void *p)
+{
+    struct hvm_start_info *si = p;
+
+    if ( si->cmdline_paddr )
+        strncpy(cmdline, to_virt(si->cmdline_paddr), MAX_CMDLINE_SIZE - 1);
+}
 #endif
 
 /*
@@ -139,6 +155,7 @@ arch_init(void *par)
           shared_info. Use xprintk instead. */
        get_console(par);
        get_xenbus(par);
+       get_cmdline(par);
        si = par;
        memcpy(&start_info, si, sizeof(*si));
 
@@ -153,8 +170,7 @@ arch_init(void *par)
        printk("   mod_start: 0x%lx(VA)\n", si->mod_start);
        printk("     mod_len: %lu\n", si->mod_len);
        printk("       flags: 0x%x\n", (unsigned int)si->flags);
-       printk("    cmd_line: %s\n",
-                       si->cmd_line ? (const char *)si->cmd_line : "NULL");
+       printk("    cmd_line: %s\n", cmdline);
        printk("       stack: %p-%p\n", stack, stack + sizeof(stack));
 
        /* Grab the shared_info pointer and put it in a safe place. */
diff --git a/include/kernel.h b/include/kernel.h
index 13e3274..d37ddda 100644
--- a/include/kernel.h
+++ b/include/kernel.h
@@ -1,6 +1,9 @@
 #ifndef _KERNEL_H_
 #define _KERNEL_H_
 
+#define MAX_CMDLINE_SIZE 1024
+extern char cmdline[MAX_CMDLINE_SIZE];
+
 void start_kernel(void);
 void do_exit(void) __attribute__((noreturn));
 void arch_do_exit(void);
diff --git a/kernel.c b/kernel.c
index 437e5b4..f22997e 100644
--- a/kernel.c
+++ b/kernel.c
@@ -48,6 +48,7 @@
 #include <xen/version.h>
 
 uint8_t xen_features[XENFEAT_NR_SUBMAPS * 32];
+char cmdline[MAX_CMDLINE_SIZE];
 
 void setup_xen_features(void)
 {
diff --git a/main.c b/main.c
index 4ec40b5..71e3be3 100644
--- a/main.c
+++ b/main.c
@@ -6,6 +6,7 @@
 
 #ifdef HAVE_LIBC
 #include <os.h>
+#include <kernel.h>
 #include <sched.h>
 #include <console.h>
 #include <netfront.h>
@@ -134,7 +135,7 @@ static void call_main(void *p)
 #define PARSE_ARGS_COUNT(ARGS) PARSE_ARGS(ARGS, argc++, c++, )
 #define PARSE_ARGS_STORE(ARGS) PARSE_ARGS(ARGS, argv[argc++] = c, memmove(c, c 
+ 1, strlen(c + 1) + 1), *c++ = 0)
 
-    PARSE_ARGS_COUNT((char*)start_info.cmd_line);
+    PARSE_ARGS_COUNT(cmdline);
 #ifdef CONFIG_QEMU_XS_ARGS
     PARSE_ARGS_COUNT(domargs);
 #endif
@@ -143,7 +144,7 @@ static void call_main(void *p)
     argv[0] = "main";
     argc = 1;
 
-    PARSE_ARGS_STORE((char*)start_info.cmd_line)
+    PARSE_ARGS_STORE(cmdline)
 #ifdef CONFIG_QEMU_XS_ARGS
     PARSE_ARGS_STORE(domargs)
 #endif
-- 
2.6.6


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