[U-Boot] [PATCH 1/2] image: Implement IH_TYPE_KERNEL_ANYLOAD

Stephen Warren swarren at nvidia.com
Thu Nov 10 20:05:58 CET 2011


On 11/10/2011 11:53 AM, Wolfgang Denk wrote:
> Dear Stephen Warren,
> 
> In message <4EBBF894.2000409 at nvidia.com> you wrote:
>>
>>> I don't like this name.  "ANYLOAD" doesn't really make sense to me; I
>>> would interpet this as "U-Boot is free to load the image to any
>>> address it likes" - which is not what I think you mean.
>>
>> I think ANYLOAD describes the situation correctly:
> 
> Sorry about the nitpicking, but I disagree.

OK, I'll rework the patch based on your desired naming.

However, I do wish to point out that U-Boot's use of the term "load" for
what is really a "copy"/"move" is incorrect according to the typically
accepted meaning of the word "load". The extload/fatload commands use
"load" correctly. I admit relocate is also not a correct phrase to
describe what's happening.

...
>> I deliberately didn't pick ZIMAGE, since I can't say for certain that
>> only zImages are relocatable across all kernel image formats across all
>> architectures. And note that ANYLOAD could well be applicable to
>> non-Linux OSs for all I know; bootm appears to be able to boot a whole
>> variety of other OSs, and I wouldn't be entirely surprised if at least
>> one of them had fully relocatable images like ARM Linux kernel zImages.
> 
> No. "bootm" follows exactly the Linux kernel calling conventions in
> all details from passing specific values in specific registers,
> putting specific data at certain addresses / address ranges, etc.
> "bootm" is to boot Linux.  I am not aware of any other OS that can be
> successfully booted with the "bootm" command (and ifso, it probably
> gould be started with "go" as well).

I didn't want to burden my previous email with details, and I quite
admit I may be wrong here since I'm not familiar with U-Boot's code, but
what about the following in cmd_bootm.c:

static boot_os_fn *boot_os[] = {
#ifdef CONFIG_BOOTM_LINUX
	[IH_OS_LINUX] = do_bootm_linux,
#endif
#ifdef CONFIG_BOOTM_NETBSD
	[IH_OS_NETBSD] = do_bootm_netbsd,
#endif
#ifdef CONFIG_LYNXKDI
	[IH_OS_LYNXOS] = do_bootm_lynxkdi,
#endif
#ifdef CONFIG_BOOTM_RTEMS
	[IH_OS_RTEMS] = do_bootm_rtems,
#endif
#if defined(CONFIG_BOOTM_OSE)
	[IH_OS_OSE] = do_bootm_ose,
#endif
#if defined(CONFIG_CMD_ELF)
	[IH_OS_VXWORKS] = do_bootm_vxworks,
	[IH_OS_QNX] = do_bootm_qnxelf,
#endif
#ifdef CONFIG_INTEGRITY
	[IH_OS_INTEGRITY] = do_bootm_integrity,
#endif
};

Don't they allow the bootm command to boot other OSs? Those functions
certainly appear to be called at the end of cmd_bootm() to do the actual
kernel parameter setup and boot.

-- 
nvpublic


More information about the U-Boot mailing list