From 30d8caf7c625203b295a78f143820cdc3124830b Mon Sep 17 00:00:00 2001 From: "mostrows@watson.ibm.com" Date: Fri, 9 Jun 2006 09:06:12 -0400 Subject: [PATCH] [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 Signed-off-by: Paul Mackerras --- arch/powerpc/boot/main.c | 27 +++++++++++++++++++++++++++ arch/powerpc/boot/prom.h | 7 +++++++ 2 files changed, 34 insertions(+) diff --git a/arch/powerpc/boot/main.c b/arch/powerpc/boot/main.c index 816446f0e49..b66634c9ea3 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", diff --git a/arch/powerpc/boot/prom.h b/arch/powerpc/boot/prom.h index 3e2ddd4a5a8..a57b184c564 100644 --- a/arch/powerpc/boot/prom.h +++ b/arch/powerpc/boot/prom.h @@ -31,4 +31,11 @@ static inline int getprop(void *phandle, const char *name, return call_prom("getprop", 4, 1, phandle, name, buf, buflen); } + +static inline int setprop(void *phandle, const char *name, + void *buf, int buflen) +{ + return call_prom("setprop", 4, 1, phandle, name, buf, buflen); +} + #endif /* _PPC_BOOT_PROM_H_ */ -- 2.32.0.93.g670b81a890