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Date: Thu, 15 Sep 2011 11:08:57 +0200
From: Maarten Lankhorst <m.b.lankhorst@...il.com>
To: Matt Domsch <Matt_Domsch@...l.com>
CC: Matt Fleming <matt@...sole-pimps.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"H. Peter Anvin" <hpa@...ux.intel.com>,
Matthew Garrett <mjg@...hat.com>,
"x86@...nel.org" <x86@...nel.org>, Ingo Molnar <mingo@...e.hu>,
Thomas Gleixner <tglx@...utronix.de>,
Mike Waychison <mikew@...gle.com>,
Andi Kleen <andi@...stfloor.org>, jordan_hargrave@...l.com
Subject: Re: [PATCH v2 10/10] x86, efi: EFI boot stub support
On 09/15/2011 10:04 AM, Maarten Lankhorst wrote:
> Hey Matt,
>
> On 09/15/2011 06:52 AM, Matt Domsch wrote:
>> On Wed, Sep 14, 2011 at 11:07:58AM -0500, Matt Fleming wrote:
>>> On Tue, 2011-09-13 at 16:33 +0200, Maarten Lankhorst wrote:
>>>> This version seems to boot for me.
>>> Yay! Thanks for testing.
>>>
>>>> Is it useful to add 32-bits support though?
>>>> It seems that only some older versions of OSX use it. I could see if I can
>>>> revive my mac mini, iirc it has 32-bits efi, or at least used to have.
>>> 32-bit UEFI platforms do exist, so I think it's worth supporting them.
>>>
>>>> Do I need to pass anything to add it to efibootmgr?
>>>>
>>>> I tried something like this:
>>>> echo "args" | efibootmgr -c -l '\vmlinuz.efi' -L 'Native EFI linux boot' -@ - -u -d /dev/sdb
>>>>
>>>> And it boots vmlinuz.efi, but the arguments I passed do not appear to
>>>> have any effect.
>>> No idea, I've never used efibootmgr. Let's add Matt Domsch to the
>>> discussion (now Cc'd).
>> Maarten, do you not see your 'args' in /proc/cmdline after booting the
>> entry? From reading this thread, that's what you should see.
>>
>> Can you provide an 'efibootmgr -v' and hexdump -C
>> /sys/firmware/efi/vars/Boot* to see the args are appended as expected
>> in the boot variable in nvram?
>>
>> Adding Jordan Hargrave, who is maintainer for efibootmgr now.
> Thanks, that helped. It looks like efibootmgr stores the arguments without converting it to UCS-2.
>
> Patch below is a rough check for ascii, in which case it passes it unmodified.
>
> After this 'args' is passed succesfully. :)
>
> Should probably be folded in 10/10.
>
> Signed-off-by: Maarten Lankhorst <m.b.lankhorst@...il.com>
>
> diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
> index 6c34828..b24affb 100644
> --- a/arch/x86/boot/compressed/eboot.c
> +++ b/arch/x86/boot/compressed/eboot.c
> @@ -619,12 +619,12 @@ static efi_status_t make_boot_params(struct boot_params *boot_params,
> unsigned long cmdline;
> u8 nr_entries;
> u16 *s2;
> - u8 *s1;
> + u8 *s1, *s2_8;
> int i;
>
> hdr->type_of_loader = 0x21;
>
> - status = low_alloc(options_size, 1, &cmdline);
> + status = low_alloc(options_size+1, 1, &cmdline);
> if (status != EFI_SUCCESS)
> goto fail;
>
> @@ -633,6 +633,14 @@ static efi_status_t make_boot_params(struct boot_params *boot_params,
> /* Convert unicode cmdline to ascii */
> s1 = (u8 *)(unsigned long)hdr->cmd_line_ptr;
> s2 = (u16 *)options;
> + s2_8 = (u8*)options;
> + /* Assume the first byte is < 0x128 */
Woops, typo.
> + if (options_size > 1 && s2_8[1] && s2_8[1] < 0x80 && s2_8[0] < 0x80) {
> + s2 = NULL;
> + memcpy(s1, s2_8, options_size);
> + s1[options_size] = 0;
> + hdr->cmdline_size = options_size;
> + }
>
> if (s2 && options_size) {
> /* Skip first word, that's the kernel name */
I noticed 10/10 doesn't include the size of null pointer is this expected?
And when options_size = 0, you do a null allocation and never null-terminate.
Also in s2 && options_size you initially check for newline, but when copying
arguments, you ignore it. With echo moo | efibootmgr -@ - you'd pass a newline,
which should probably be stripped. I think this would fix both cases:
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index 6c34828..dbaaf54 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -619,12 +619,12 @@ static efi_status_t make_boot_params(struct boot_params *boot_params,
unsigned long cmdline;
u8 nr_entries;
u16 *s2;
- u8 *s1;
+ u8 *s1, *s2_8;
int i;
hdr->type_of_loader = 0x21;
- status = low_alloc(options_size, 1, &cmdline);
+ status = low_alloc(options_size+1, 1, &cmdline);
if (status != EFI_SUCCESS)
goto fail;
@@ -633,6 +633,14 @@ static efi_status_t make_boot_params(struct boot_params *boot_params,
/* Convert unicode cmdline to ascii */
s1 = (u8 *)(unsigned long)hdr->cmd_line_ptr;
s2 = (u16 *)options;
+ s2_8 = (u8*)options;
+ /* Assume the first byte is < 128 */
+ if (options_size > 1 && s2_8[1] s2_8[1] < 0x80 && s2_8[0] < 0x80) {
+ s2 = NULL;
+ memcpy(s1, s2_8, options_size);
+ s1[options_size] = '\0';
+ hdr->cmdline_size = options_size;
+ }
if (s2 && options_size) {
/* Skip first word, that's the kernel name */
@@ -655,6 +663,11 @@ static efi_status_t make_boot_params(struct boot_params *boot_params,
*s1 = '\0';
}
+ if (!hdr->cmdline_size)
+ *s1 = '\0';
+ else if (hdr->cmd_line_ptr[hdr->cmdline_size-1] == '\n')
+ hdr->cmd_line_ptr[--hdr->cmdline_size] = '\0';
+
hdr->ramdisk_image = 0;
hdr->ramdisk_size = 0;
--
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