qemu-system-ppc -prep initial port

PATCH New Milton Miller 1 participant 1 message Aug 28, 2007

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Device tree bindings PowerPC

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Milton Miller

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2007-08-28 04:03 UTC #0 lore raw

PATCH 1/1 qemu-system-ppc -prep initial port

Hi.

Some people have been asking about booting powerpc kernels on qemu.

Based on some comments about the existing rom for qemu, I looked at OpenHackWare enough to discern how qemu started its execution and how it gets its config.

I then proceeded to write a wrapper patch to use as the rom and then proceeded with a minimal platform (based on David Gibson's prep patch) to boot a ARCH=powerpc kernel.

These patches are being posted early to allow others to use them, they are not ready to be merged.

What works:
-prep (not default pmac, or core99 in later qemu) serial console in bootwrapper
serial console in kernel (console=ttyS0)
kernel must be loaded with --kernel=
vmlinux, or vmlinuz (gzip'ed elf).
zImage.qemu, zImage.initrd.qemu (with compiler assumptions)
-initrd (optional)
-append (optional)
ide-disk and cdrom appear to work
floppy is untested, and needs io port added.

What doesn't work:
boot from disk
vga (needs bios post, maybe pci)
pci (config cycles are not working, at least on 0.6.3)

How it works:
wrapper is compiled to run as rom
copied from rom to ram (linked address) supplies initial device tree blob (because dtb = NULL) reads nvram for memory size, kernel, initrd, command line
if invoked with device tree, then it only uses attached kernel
initrd either attached or from kernel

what you need:

	2.6.23-rc3 + [ from powerpc.git for-2.6.24 branch ]
	commit 0602801c22ea1767cd0298b11da140bd5cb764d2
	    [POWERPC] bootwrapper: dt_xlate_range() bugfixes
	commit a73ac50c4787b1b28d5c94bb18c60352f5dd7d6f
	    [POWERPC] bootwrapper: Add dt_is_compatible()
	commit 6e913c67b3eb93e2b8bc1dc0ff854f00a760f41b
	    [POWERPC] bootwrapper: Add 16-bit I/O, sync(), eieio(), and barrier()
	commit dc4f397d6e385c4ea0fe9732df911a86f1a78c9a
	    [POWERPC] bootwrapper: serial_console_init() fixes
	commit 2f1d4899321be87bc5f0c4ee0e62c9d9ced05f80
	    [POWERPC] bootwrapper: Move linker symbols into ops.h

	tell wrapper where initrd is, so it can move it if needed
		http://patchwork.ozlabs.org/linuxppc/patch?id=12168

	tell code where vmlinuz is
		http://patchwork.ozlabs.org/linuxppc/patch?id=12178

	build rom without vmlinuz
		http://patchwork.ozlabs.org/linuxppc/patch?id=12180

	Subject: Move serial_dev_init to device_initcall()
		http://patchwork.ozlabs.org/linuxppc/patch?id=13097

To run:
build ppc_rom.bin using CONFIG_DEVICE_TREE=prep.dts with the dtc installed. This will be based on zBoot.qemu and will not have a kernel attached. Put this in a directory and invoke qemu-system-ppc -prep -L <dir-with-rom> -kernel <kernel> where kernel is either zImage.qemu or a (possibly compressed) vmlinux elf , add ide drives, -append, and -initrd as desired.

My tree has all patches in for-2.6.24 that touch arch/powerpc/boot plus ojn's patch plus my kexec series plus the prep patch, so there will be some rejects, especially to makefiles etc.

The first hunk to main.c to check loader_info for a command line after the fixup callback should be a seperate patch.

The boot/Makefile has a hack to avoid ovewriting qemu.dtb.

arch/powerpc/boot/main.c +5 -0

Index: kernel/arch/powerpc/boot/main.c
===================================================================
@@ -181,6 +181,11 @@ void start(void)
 	if (platform_ops.fixups)
 		platform_ops.fixups();
 
+	/* check again, in case fixups told us about it */
+	if ((loader_info.cmdline_len > 0) && (cmdline[0] == '\0'))
+		memmove(cmdline, loader_info.cmdline,
+			min(loader_info.cmdline_len, COMMAND_LINE_SIZE-1));
+
 	printf("\n\rzImage starting: loaded at 0x%p (sp: 0x%p)\n\r",
 	       _start, get_sp());

arch/powerpc/boot/qemu.c new file +237 -0

237 lines not on this page · raw message

arch/powerpc/boot/Makefile +7 -3

Index: kernel/arch/powerpc/boot/Makefile
===================================================================
@@ -49,7 +49,7 @@ src-wlib := string.S crt0.S stdio.c main
 		cpm-serial.c
 src-plat := of.c cuboot-83xx.c cuboot-85xx.c holly.c crt0_kexec.S \
 		cuboot-ebony.c treeboot-ebony.c prpmc2800.c crt0_bml.S bml.c \
-		ps3-head.S ps3-hvcall.S ps3.c prep.c \
+		ps3-head.S ps3-hvcall.S ps3.c prep.c qemu.c \
 		treeboot-bamboo.c cuboot-8xx.c cuboot-pq2.c
 src-boot := $(src-wlib) $(src-plat) empty.c

@@ -144,6 +144,7 @@ image-$(CONFIG_PPC_HOLLY)		+= zImage.hol
 image-$(CONFIG_PPC_PRPMC2800)		+= zImage.prpmc2800
 image-$(CONFIG_PPC_ISERIES)		+= zImage.iseries
 image-$(CONFIG_PPC_PREP)		+= zImage.prep
+image-$(CONFIG_PPC_QEMU)		+= zImage.qemu zBoot.qemu
 image-$(CONFIG_DEFAULT_UIMAGE)		+= uImage
 image-$(CONFIG_KEXEC)			+= $(kexec-y)
 image-$(CONFIG_KEXEC)			+= $(patsubst zImage%,zBoot%,$(kexec-y))

@@ -201,6 +202,9 @@ $(obj)/zImage.iseries: vmlinux
 $(obj)/zBoot.%: $(wrapperbits) $(dts)
 	$(call if_changed,wrap,$*,$(dts),,,$(obj)/empty.o)
 
+# horrible hack to avoid overlapping calls to wrapper script clobbering dtb.
+$(obj)/zImage.qemu: $(obj)/zBoot.qemu
+
 $(obj)/zImage.ps3: vmlinux  $(wrapper) $(wrapperbits) $(srctree)/$(src)/dts/ps3.dts
 	$(STRIP) -s -R .comment $< -o vmlinux.strip
 	$(call cmd,wrap,ps3,$(srctree)/$(src)/dts/ps3.dts,,)

@@ -234,8 +238,8 @@ install: $(CONFIGURE) $(addprefix $(obj)
 	sh -x $(srctree)/$(src)/install.sh "$(KERNELRELEASE)" vmlinux System.map "$(INSTALL_PATH)" $<
 
 # anything not in $(targets)
-clean-files += $(image-) $(initrd-) zImage zImage.initrd cuImage.* treeImage.* \
-	otheros.bld $(kexec-)
+clean-files += $(image-) $(initrd-) zImage zImage.initrd cuImage.* treeImage.*
+clean-files += otheros.bld ppc_rom.bin $(kexec-)
 
 # clean up files cached by wrapper
 clean-kernel := vmlinux.strip vmlinux.bin empty.o.bin

arch/powerpc/boot/dts/qemu.dts new file +100 -0

100 lines not on this page · raw message

arch/powerpc/platforms/Kconfig +1 -0

Index: kernel/arch/powerpc/platforms/Kconfig
===================================================================
@@ -47,6 +47,7 @@ source "arch/powerpc/platforms/chrp/Kcon
 source "arch/powerpc/platforms/52xx/Kconfig"
 source "arch/powerpc/platforms/powermac/Kconfig"
 source "arch/powerpc/platforms/prep/Kconfig"
+source "arch/powerpc/platforms/qemu/Kconfig"
 source "arch/powerpc/platforms/maple/Kconfig"
 source "arch/powerpc/platforms/pasemi/Kconfig"
 source "arch/powerpc/platforms/celleb/Kconfig"

arch/powerpc/boot/wrapper +49 -0

53 lines not on this page · raw message

arch/powerpc/platforms/qemu/Kconfig new file +10 -0

Index: kernel/arch/powerpc/platforms/qemu/Kconfig
===================================================================
@@ -0,0 +1,10 @@
+config PPC_QEMU
+	bool "PowerPC Reference Platform (PReP) based QEMU emulated systems"
+	depends on PPC_MULTIPLATFORM && PPC32
+	select PPC_I8259
+	select PPC_INDIRECT_PCI
+	select PPC_UDBG_16550
+	select PPC_NATIVE
+	select WANT_DEVICE_TREE
+	default n
+

arch/powerpc/platforms/qemu/Makefile new file +2 -0

Index: kernel/arch/powerpc/platforms/qemu/Makefile
===================================================================
@@ -0,0 +1,2 @@
+obj-y			+= setup.o
+obj-$(CONFIG_PCI)	+= pci.o

arch/powerpc/platforms/qemu/pci.c new file +133 -0

133 lines not on this page · raw message

arch/powerpc/platforms/qemu/setup.c new file +290 -0

290 lines not on this page · raw message

arch/powerpc/platforms/Makefile +1 -0

Index: kernel/arch/powerpc/platforms/Makefile
===================================================================
@@ -7,6 +7,7 @@ endif
 endif
 obj-$(CONFIG_PPC_CHRP)		+= chrp/
 obj-$(CONFIG_PPC_PREP)		+= prep/
+obj-$(CONFIG_PPC_QEMU)		+= qemu/
 #obj-$(CONFIG_4xx)		+= 4xx/
 obj-$(CONFIG_44x)		+= 44x/
 obj-$(CONFIG_PPC_MPC52xx)	+= 52xx/

arch/powerpc/boot/.gitignore +1 -0

Index: kernel/arch/powerpc/boot/.gitignore
===================================================================
@@ -17,6 +17,7 @@ infutil.h
 kernel-vmlinux.strip.c
 kernel-vmlinux.strip.gz
 mktree
+ppc_rom.bin
 uImage
 cuImage.*
 zImage