On Mon, Jul 13, 2009 at 10:27 PM, Kumar Galagalak@kernel.crashing.org wrote:
My question is how does the kernel cmd line being passed? I know it's possible for u-boot to patching the target uImage (assume we're using kernel image cuImage.bamboo)'s dtb by overwrite the dtb ``chosen'' section, but I didn't find any code in u-boot trying to do this.
Did you look at common/fdt_support.c and fdt_chosen()
The command lines is passed in there as "bootargs"
That's all I need ;-)
Even more, after the kernel is bootstraping, (assume we're using a bamboo board), we'll run into:
static bd_t bd;
... void platform_init(unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6, unsigned long r7) { CUBOOT_INIT(); bamboo_init(&bd.bi_enetaddr, &bd.bi_enet1addr); }
...
void bamboo_init(void *mac0, void *mac1) { platform_ops.fixups = bamboo_fixups; platform_ops.exit = ibm44x_dbcr_reset; bamboo_mac0 = mac0; bamboo_mac1 = mac1; fdt_init(_dtb_start); serial_console_init(); } ...
this code will assume $r3 is passed as a ``bd_t'' structure, but $r3 passed in I think it's the dtb address (not bd_t), and bamboo_init will set the NIC wrong MAC addresses. I'm quite sure I misunderstand something between u-boot & linux kernel, could some help me to figure it out? Thanks in advance!
Where is the code you are referencing above? This is the "old" bd_t style of booting. Only the boot wrapper code or and old kernel would still be using this.
- k
the code is from arch/powerpc/boot/cuboot-bamboo.c, and the kernel is 2.6.30.1, the boot image I'm using is something like cuImage.bamboo, I checked zImage.ld.S, and found that when we're running cuImage.bamboo, we actually fall into arch/powerpc/boot/crt0.S:_zimage_start(), which will call platform_init() and then bamboo_init() finally. but sounds like if we passing r3 as fdt, then the code (platform_init, etc.., and even arch/powerpc/kernel/head_xxx.S start() function, only comments, though) is actually wrong, isn't it? Thank you very much for help.
Best Regards, Wang