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authormostrows@watson.ibm.com <mostrows@watson.ibm.com>2006-06-09 09:06:12 -0400
committerPaul Mackerras <paulus@samba.org>2006-06-15 19:31:25 +1000
commit30d8caf7c625203b295a78f143820cdc3124830b (patch)
treea8a759a1fcf3d8b53e1d9a587943932b4fc9011c /arch/powerpc/boot/main.c
parent204face4fb3ba2ca09a4073e7debc595e14c2388 (diff)
downloadlinux-30d8caf7c625203b295a78f143820cdc3124830b.tar.bz2
[POWERPC] Editable kernel command-line in zImage binary.
zImage will set /chosen/bootargs (if it is otherwise empty) with the contents of a buffer in the section "__builtin_cmdline". This permits tools to edit zImage binaries to set the command-line eventually processed by vmlinux. -- Signed-off-by: Michal Ostrowski <mostrows@watson.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/boot/main.c')
-rw-r--r--arch/powerpc/boot/main.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/arch/powerpc/boot/main.c b/arch/powerpc/boot/main.c
index 816446f0e497..b66634c9ea34 100644
--- a/arch/powerpc/boot/main.c
+++ b/arch/powerpc/boot/main.c
@@ -33,6 +33,14 @@ extern char _vmlinux_end[];
extern char _initrd_start[];
extern char _initrd_end[];
+/* A buffer that may be edited by tools operating on a zImage binary so as to
+ * edit the command line passed to vmlinux (by setting /chosen/bootargs).
+ * The buffer is put in it's own section so that tools may locate it easier.
+ */
+static char builtin_cmdline[512]
+ __attribute__((section("__builtin_cmdline")));
+
+
struct addr_range {
unsigned long addr;
unsigned long size;
@@ -204,6 +212,23 @@ static int is_elf32(void *hdr)
return 1;
}
+void export_cmdline(void* chosen_handle)
+{
+ int len;
+ char cmdline[2] = { 0, 0 };
+
+ if (builtin_cmdline[0] == 0)
+ return;
+
+ len = getprop(chosen_handle, "bootargs", cmdline, sizeof(cmdline));
+ if (len > 0 && cmdline[0] != 0)
+ return;
+
+ setprop(chosen_handle, "bootargs", builtin_cmdline,
+ strlen(builtin_cmdline) + 1);
+}
+
+
void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
{
int len;
@@ -289,6 +314,8 @@ void start(unsigned long a1, unsigned long a2, void *promptr, void *sp)
memmove((void *)vmlinux.addr,(void *)vmlinuz.addr,vmlinuz.size);
}
+ export_cmdline(chosen_handle);
+
/* Skip over the ELF header */
#ifdef DEBUG
printf("... skipping 0x%lx bytes of ELF header\n\r",