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Commit 3e3c4860 authored by Daniel Drake's avatar Daniel Drake Committed by H. Peter Anvin
Browse files

x86, olpc: Rework BIOS signature check 



The XO-1.5 laptop is not currently detected as an OLPC machine because
it fails this XO-1-centric check.

Now that we have OLPC OFW support in the kernel, a more sensible
check is to see if we found OFW during boot and check the architecture
property.

Also remove a now-meaningless codepath, as we're always going to have
OFW support with OLPC.

Signed-off-by: default avatarDaniel Drake <dsd@laptop.org>
LKML-Reference: <20100923162846.D8D409D401B@zog.reactivated.net>
Cc: Andres Salomon <dilinger@queued.net>
Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 76fb6570

arch/x86/Kconfig

+2 −1
Original line number Diff line number Diff line
@@ -2061,6 +2061,7 @@ config SCx200HR_TIMER 
config OLPC

	bool "One Laptop Per Child support"

	select GPIOLIB

	select OLPC_OPENFIRMWARE

	---help---

	  Add support for detecting the unique features of the OLPC

	  XO hardware.
@@ -2068,7 +2069,7 @@ config OLPC 
config OLPC_OPENFIRMWARE

	bool "Support for OLPC's Open Firmware"

	depends on !X86_64 && !X86_PAE

	default y if OLPC

	default n

	help

	  This option adds support for the implementation of Open Firmware

	  that is used on the OLPC XO-1 Children's Machine.

arch/x86/include/asm/olpc_ofw.h

+4 −0
Original line number Diff line number Diff line
@@ -21,10 +21,14 @@ extern void olpc_ofw_detect(void); 
/* install OFW's pde permanently into the kernel's pgtable */

extern void setup_olpc_ofw_pgd(void);



/* check if OFW was detected during boot */

extern bool olpc_ofw_present(void);



#else /* !CONFIG_OLPC_OPENFIRMWARE */



static inline void olpc_ofw_detect(void) { }

static inline void setup_olpc_ofw_pgd(void) { }

static inline bool olpc_ofw_present(void) { return false; }



#endif /* !CONFIG_OLPC_OPENFIRMWARE */

arch/x86/kernel/olpc.c

+25 −33
Original line number Diff line number Diff line
@@ -183,8 +183,21 @@ int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen, 
}

EXPORT_SYMBOL_GPL(olpc_ec_cmd);



#ifdef CONFIG_OLPC_OPENFIRMWARE

static void __init platform_detect(void)

static bool __init check_ofw_architecture(void)

{

	size_t propsize;

	char olpc_arch[5];

	const void *args[] = { NULL, "architecture", olpc_arch, (void *)5 };

	void *res[] = { &propsize };



	if (olpc_ofw("getprop", args, res)) {

		printk(KERN_ERR "ofw: getprop call failed!\n");

		return false;

	}

	return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0;

}



static u32 __init get_board_revision(void)

{

	size_t propsize;

	__be32 rev;
@@ -193,46 +206,27 @@ static void __init platform_detect(void) 


	if (olpc_ofw("getprop", args, res) || propsize != 4) {

		printk(KERN_ERR "ofw: getprop call failed!\n");

		rev = cpu_to_be32(0);

		return cpu_to_be32(0);

	}

	olpc_platform_info.boardrev = be32_to_cpu(rev);

	return be32_to_cpu(rev);

}

#else

static void __init platform_detect(void)



static bool __init platform_detect(void)

{

	/* stopgap until OFW support is added to the kernel */

	olpc_platform_info.boardrev = olpc_board(0xc2);

	if (!check_ofw_architecture())

		return false;

	olpc_platform_info.flags |= OLPC_F_PRESENT;

	olpc_platform_info.boardrev = get_board_revision();

	return true;

}

#endif



static int __init olpc_init(void)

{

	unsigned char *romsig;



	/* The ioremap check is dangerous; limit what we run it on */

	if (!is_geode() || cs5535_has_vsa2())

	if (!olpc_ofw_present() || !platform_detect())

		return 0;



	spin_lock_init(&ec_lock);



	romsig = ioremap(0xffffffc0, 16);

	if (!romsig)

		return 0;



	if (strncmp(romsig, "CL1   Q", 7))

		goto unmap;

	if (strncmp(romsig+6, romsig+13, 3)) {

		printk(KERN_INFO "OLPC BIOS signature looks invalid.  "

				"Assuming not OLPC\n");

		goto unmap;

	}



	printk(KERN_INFO "OLPC board with OpenFirmware %.16s\n", romsig);

	olpc_platform_info.flags |= OLPC_F_PRESENT;



	/* get the platform revision */

	platform_detect();



	/* assume B1 and above models always have a DCON */

	if (olpc_board_at_least(olpc_board(0xb1)))

		olpc_platform_info.flags |= OLPC_F_DCON;
@@ -254,8 +248,6 @@ static int __init olpc_init(void) 
			olpc_platform_info.boardrev >> 4,

			olpc_platform_info.ecver);



unmap:

	iounmap(romsig);

	return 0;

}

arch/x86/kernel/olpc_ofw.c

+6 −0
Original line number Diff line number Diff line
@@ -74,6 +74,12 @@ int __olpc_ofw(const char *name, int nr_args, const void **args, int nr_res, 
}

EXPORT_SYMBOL_GPL(__olpc_ofw);



bool olpc_ofw_present(void)

{

	return olpc_ofw_cif != NULL;

}

EXPORT_SYMBOL_GPL(olpc_ofw_present);



/* OFW cif _should_ be above this address */

#define OFW_MIN 0xff000000