Commit 35af89eb authored by David Gibson's avatar David Gibson Committed by Paul Mackerras
Browse files

[POWERPC] Cleanup zImage handling of kernel entry with flat device tree 



This makes 2 changes to clean up the flat device tree handling
logic in the zImage wrapper.

First, there were two callbacks from the dt_ops structure used for
producing a final flat tree to pass to the kerne: dt_ops.ft_pack()
which packed the flat tree (possibly a no-op) and dt_ops.ft_addr()
which retreived the address of the final blob.  Since they were only
ever called together, this patch combines the two into a single new
callback, dt_ops.finalize().  This new callback does whatever
platform-dependent things are necessary to produce a final flat device
tree blob, and returns the blob's addres.

Second, the current logic calls the kernel with a flat device tree if
one is build into the zImage wrapper, otherwise it boots the kernel
with a PROM pointer, expecting the kernel to copy the OF device tree
itself.  This approach precludes the possibility of the platform
wrapper code building a flat device tree from whatever
platform-specific information firmware provides.  Thus, this patch
takes the more sensible approach of invoking the kernel with a flat
tree if the dt_ops.finalize callback provides one (by whatever means).

So, the dt_ops.finalize callback can be NULL, or can be a function
which returns NULL.  In either case, the zImage wrapper logic assumes
that this is a platform with OF and invokes the kernel accordingly.

Signed-off-by: default avatarDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent f79e083c

arch/powerpc/boot/flatdevtree_misc.c

+2 −7
Original line number Diff line number Diff line
@@ -33,13 +33,9 @@ static int ft_setprop(const void *phandle, const char *propname, 
	return ft_set_prop(&cxt, phandle, propname, buf, buflen);

}



static void ft_pack(void)

static unsigned long ft_finalize(void)

{

	ft_end_tree(&cxt);

}



static unsigned long ft_addr(void)

{

	return (unsigned long)cxt.bph;

}
@@ -48,8 +44,7 @@ int ft_init(void *dt_blob, unsigned int max_size, unsigned int max_find_device) 
	dt_ops.finddevice = ft_finddevice;

	dt_ops.getprop = ft_getprop;

	dt_ops.setprop = ft_setprop;

	dt_ops.ft_pack = ft_pack;

	dt_ops.ft_addr = ft_addr;

	dt_ops.finalize = ft_finalize;



	return ft_open(&cxt, dt_blob, max_size, max_find_device,

			platform_ops.realloc);

arch/powerpc/boot/main.c

+11 −4
Original line number Diff line number Diff line
@@ -298,6 +298,7 @@ void start(unsigned long a1, unsigned long a2, void *promptr, void *sp) 
{

	kernel_entry_t kentry;

	char cmdline[COMMAND_LINE_SIZE];

	unsigned long ft_addr = 0;



	memset(__bss_start, 0, _end - __bss_start);

	memset(&platform_ops, 0, sizeof(platform_ops));
@@ -328,14 +329,20 @@ void start(unsigned long a1, unsigned long a2, void *promptr, void *sp) 
		set_cmdline(cmdline);

	}



	printf("Finalizing device tree...");

	if (dt_ops.finalize)

		ft_addr = dt_ops.finalize();

	if (ft_addr)

		printf(" flat tree at 0x%lx\n\r", ft_addr);

	else

		printf(" using OF tree (promptr=%p)\n\r", promptr);



	if (console_ops.close)

		console_ops.close();



	kentry = (kernel_entry_t) vmlinux.addr;

	if (_dtb_end > _dtb_start) {

		dt_ops.ft_pack();

		kentry(dt_ops.ft_addr(), 0, NULL);

	}

	if (ft_addr)

		kentry(ft_addr, 0, NULL);

	else

		/* XXX initrd addr/size should be passed in properties */

		kentry(initrd.addr, initrd.size, promptr);

arch/powerpc/boot/ops.h

+1 −2
Original line number Diff line number Diff line
@@ -35,8 +35,7 @@ struct dt_ops { 
			const int buflen);

	int	(*setprop)(const void *phandle, const char *name,

			const void *buf, const int buflen);

	void	(*ft_pack)(void);

	unsigned long (*ft_addr)(void);

	unsigned long (*finalize)(void);

};

extern struct dt_ops dt_ops;

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