Commit b31297f0 authored by Vincent Whitchurch's avatar Vincent Whitchurch Committed by Richard Weinberger
Browse files

um: Add devicetree support 



Add a dtb=<filename> option to boot UML with a devicetree blob.  This
can be used for testing driver code using UML.

Signed-off-by: default avatarVincent Whitchurch <vincent.whitchurch@axis.com>
[rw: Add dependency on CONFIG_OF]
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent 361640b4

arch/um/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ config UML 
	select HAVE_DEBUG_KMEMLEAK

	select HAVE_DEBUG_BUGVERBOSE

	select NO_DMA if !UML_DMA_EMULATION

	select OF_EARLY_FLATTREE if OF

	select GENERIC_IRQ_SHOW

	select GENERIC_CPU_DEVICES

	select HAVE_GCC_PLUGINS

arch/um/kernel/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ obj-y += load_file.o 


obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o

obj-$(CONFIG_GPROF)	+= gprof_syms.o

obj-$(CONFIG_OF) += dtb.o

obj-$(CONFIG_EARLY_PRINTK) += early_printk.o

obj-$(CONFIG_STACKTRACE) += stacktrace.o

obj-$(CONFIG_GENERIC_PCI_IOMAP) += ioport.o

arch/um/kernel/dtb.c

0 → 100644
+41 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only



#include <linux/init.h>

#include <linux/of_fdt.h>

#include <linux/printk.h>

#include <linux/memblock.h>

#include <init.h>



#include "um_arch.h"



static char *dtb __initdata;



void uml_dtb_init(void)

{

	long long size;

	void *area;



	area = uml_load_file(dtb, &size);

	if (!area)

		return;



	if (!early_init_dt_scan(area)) {

		pr_err("invalid DTB %s\n", dtb);

		memblock_free(area, size);

		return;

	}



	unflatten_device_tree();

	early_init_fdt_scan_reserved_mem();

}



static int __init uml_dtb_setup(char *line, int *add)

{

	dtb = line;

	return 0;

}



__uml_setup("dtb=", uml_dtb_setup,

"dtb=<file>\n"

"    Boot the kernel with the devicetree blob from the specified file.\n"

);

arch/um/kernel/um_arch.c

+3 −0
Original line number Diff line number Diff line
@@ -29,6 +29,8 @@ 
#include <mem_user.h>

#include <os.h>



#include "um_arch.h"



#define DEFAULT_COMMAND_LINE_ROOT "root=98:0"

#define DEFAULT_COMMAND_LINE_CONSOLE "console=tty"
@@ -407,6 +409,7 @@ void __init setup_arch(char **cmdline_p) 
	stack_protections((unsigned long) &init_thread_info);

	setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);

	mem_total_pages(physmem_size, iomem_size, highmem);

	uml_dtb_init();

	read_initrd();



	paging_init();

arch/um/kernel/um_arch.h

+6 −0
Original line number Diff line number Diff line
@@ -5,4 +5,10 @@ 


extern void * __init uml_load_file(const char *filename, unsigned long long *size);



#ifdef CONFIG_OF

extern void __init uml_dtb_init(void);

#else

static inline void uml_dtb_init(void) { }

#endif



#endif