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…/git/x86/linux-2.6-x86-bigbox-bootparam

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86-bigbox-bootparam:
  x86, boot: Document for linked list of struct setup_data
  x86, boot: export linked list of struct setup_data via debugfs
  x86, boot: add linked list of struct setup_data
  x86, boot: add free_early to early reservation machanism
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Linus Torvalds committed Apr 26, 2008
2 parents 0124cec + fb88438 commit 539a5fe
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Showing 8 changed files with 270 additions and 6 deletions.
26 changes: 26 additions & 0 deletions Documentation/i386/boot.txt
Original file line number Diff line number Diff line change
Expand Up @@ -42,6 +42,8 @@ Protocol 2.05: (Kernel 2.6.20) Make protected mode kernel relocatable.
Protocol 2.06: (Kernel 2.6.22) Added a field that contains the size of
the boot command line

Protocol 2.09: (kernel 2.6.26) Added a field of 64-bit physical
pointer to single linked list of struct setup_data.

**** MEMORY LAYOUT

Expand Down Expand Up @@ -172,6 +174,8 @@ Offset Proto Name Meaning
0240/8 2.07+ hardware_subarch_data Subarchitecture-specific data
0248/4 2.08+ payload_offset Offset of kernel payload
024C/4 2.08+ payload_length Length of kernel payload
0250/8 2.09+ setup_data 64-bit physical pointer to linked list
of struct setup_data

(1) For backwards compatibility, if the setup_sects field contains 0, the
real value is 4.
Expand Down Expand Up @@ -572,6 +576,28 @@ command line is entered using the following protocol:
covered by setup_move_size, so you may need to adjust this
field.

Field name: setup_data
Type: write (obligatory)
Offset/size: 0x250/8
Protocol: 2.09+

The 64-bit physical pointer to NULL terminated single linked list of
struct setup_data. This is used to define a more extensible boot
parameters passing mechanism. The definition of struct setup_data is
as follow:

struct setup_data {
u64 next;
u32 type;
u32 len;
u8 data[0];
};

Where, the next is a 64-bit physical pointer to the next node of
linked list, the next field of the last node is 0; the type is used
to identify the contents of data; the len is the length of data
field; the data holds the real payload.


**** MEMORY LAYOUT OF THE REAL-MODE CODE

Expand Down
6 changes: 5 additions & 1 deletion arch/x86/boot/header.S
Original file line number Diff line number Diff line change
Expand Up @@ -120,7 +120,7 @@ _start:
# Part 2 of the header, from the old setup.S

.ascii "HdrS" # header signature
.word 0x0208 # header version number (>= 0x0105)
.word 0x0209 # header version number (>= 0x0105)
# or else old loadlin-1.5 will fail)
.globl realmode_swtch
realmode_swtch: .word 0, 0 # default_switch, SETUPSEG
Expand Down Expand Up @@ -227,6 +227,10 @@ hardware_subarch_data: .quad 0
payload_offset: .long input_data
payload_length: .long input_data_end-input_data

setup_data: .quad 0 # 64-bit physical pointer to
# single linked list of
# struct setup_data

# End of setup header #####################################################

.section ".inittext", "ax"
Expand Down
22 changes: 22 additions & 0 deletions arch/x86/kernel/e820_64.c
Original file line number Diff line number Diff line change
Expand Up @@ -84,6 +84,28 @@ void __init reserve_early(unsigned long start, unsigned long end, char *name)
strncpy(r->name, name, sizeof(r->name) - 1);
}

void __init free_early(unsigned long start, unsigned long end)
{
struct early_res *r;
int i, j;

for (i = 0; i < MAX_EARLY_RES && early_res[i].end; i++) {
r = &early_res[i];
if (start == r->start && end == r->end)
break;
}
if (i >= MAX_EARLY_RES || !early_res[i].end)
panic("free_early on not reserved area: %lx-%lx!", start, end);

for (j = i + 1; j < MAX_EARLY_RES && early_res[j].end; j++)
;

memcpy(&early_res[i], &early_res[i + 1],
(j - 1 - i) * sizeof(struct early_res));

early_res[j - 1].end = 0;
}

void __init early_res_to_bootmem(void)
{
int i;
Expand Down
20 changes: 20 additions & 0 deletions arch/x86/kernel/head64.c
Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,7 @@
#include <linux/string.h>
#include <linux/percpu.h>
#include <linux/start_kernel.h>
#include <linux/io.h>

#include <asm/processor.h>
#include <asm/proto.h>
Expand Down Expand Up @@ -100,6 +101,24 @@ static void __init reserve_ebda_region(void)
reserve_early(lowmem, 0x100000, "BIOS reserved");
}

static void __init reserve_setup_data(void)
{
struct setup_data *data;
unsigned long pa_data;
char buf[32];

if (boot_params.hdr.version < 0x0209)
return;
pa_data = boot_params.hdr.setup_data;
while (pa_data) {
data = early_ioremap(pa_data, sizeof(*data));
sprintf(buf, "setup data %x", data->type);
reserve_early(pa_data, pa_data+sizeof(*data)+data->len, buf);
pa_data = data->next;
early_iounmap(data, sizeof(*data));
}
}

void __init x86_64_start_kernel(char * real_mode_data)
{
int i;
Expand Down Expand Up @@ -156,6 +175,7 @@ void __init x86_64_start_kernel(char * real_mode_data)
#endif

reserve_ebda_region();
reserve_setup_data();

/*
* At this point everything still needed from the boot loader
Expand Down
163 changes: 158 additions & 5 deletions arch/x86/kernel/kdebugfs.c
Original file line number Diff line number Diff line change
Expand Up @@ -6,23 +6,171 @@
*
* This file is released under the GPLv2.
*/

#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/mm.h>

#include <asm/setup.h>

#ifdef CONFIG_DEBUG_BOOT_PARAMS
struct setup_data_node {
u64 paddr;
u32 type;
u32 len;
};

static ssize_t
setup_data_read(struct file *file, char __user *user_buf, size_t count,
loff_t *ppos)
{
struct setup_data_node *node = file->private_data;
unsigned long remain;
loff_t pos = *ppos;
struct page *pg;
void *p;
u64 pa;

if (pos < 0)
return -EINVAL;
if (pos >= node->len)
return 0;

if (count > node->len - pos)
count = node->len - pos;
pa = node->paddr + sizeof(struct setup_data) + pos;
pg = pfn_to_page((pa + count - 1) >> PAGE_SHIFT);
if (PageHighMem(pg)) {
p = ioremap_cache(pa, count);
if (!p)
return -ENXIO;
} else {
p = __va(pa);
}

remain = copy_to_user(user_buf, p, count);

if (PageHighMem(pg))
iounmap(p);

if (remain)
return -EFAULT;

*ppos = pos + count;

return count;
}

static int setup_data_open(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}

static const struct file_operations fops_setup_data = {
.read = setup_data_read,
.open = setup_data_open,
};

static int __init
create_setup_data_node(struct dentry *parent, int no,
struct setup_data_node *node)
{
struct dentry *d, *type, *data;
char buf[16];
int error;

sprintf(buf, "%d", no);
d = debugfs_create_dir(buf, parent);
if (!d) {
error = -ENOMEM;
goto err_return;
}
type = debugfs_create_x32("type", S_IRUGO, d, &node->type);
if (!type) {
error = -ENOMEM;
goto err_dir;
}
data = debugfs_create_file("data", S_IRUGO, d, node, &fops_setup_data);
if (!data) {
error = -ENOMEM;
goto err_type;
}
return 0;

err_type:
debugfs_remove(type);
err_dir:
debugfs_remove(d);
err_return:
return error;
}

static int __init create_setup_data_nodes(struct dentry *parent)
{
struct setup_data_node *node;
struct setup_data *data;
int error, no = 0;
struct dentry *d;
struct page *pg;
u64 pa_data;

d = debugfs_create_dir("setup_data", parent);
if (!d) {
error = -ENOMEM;
goto err_return;
}

pa_data = boot_params.hdr.setup_data;

while (pa_data) {
node = kmalloc(sizeof(*node), GFP_KERNEL);
if (!node) {
error = -ENOMEM;
goto err_dir;
}
pg = pfn_to_page((pa_data+sizeof(*data)-1) >> PAGE_SHIFT);
if (PageHighMem(pg)) {
data = ioremap_cache(pa_data, sizeof(*data));
if (!data) {
error = -ENXIO;
goto err_dir;
}
} else {
data = __va(pa_data);
}

node->paddr = pa_data;
node->type = data->type;
node->len = data->len;
error = create_setup_data_node(d, no, node);
pa_data = data->next;

if (PageHighMem(pg))
iounmap(data);
if (error)
goto err_dir;
no++;
}
return 0;

err_dir:
debugfs_remove(d);
err_return:
return error;
}

static struct debugfs_blob_wrapper boot_params_blob = {
.data = &boot_params,
.size = sizeof(boot_params),
.data = &boot_params,
.size = sizeof(boot_params),
};

static int __init boot_params_kdebugfs_init(void)
{
int error;
struct dentry *dbp, *version, *data;
int error;

dbp = debugfs_create_dir("boot_params", NULL);
if (!dbp) {
Expand All @@ -41,7 +189,13 @@ static int __init boot_params_kdebugfs_init(void)
error = -ENOMEM;
goto err_version;
}
error = create_setup_data_nodes(dbp);
if (error)
goto err_data;
return 0;

err_data:
debugfs_remove(data);
err_version:
debugfs_remove(version);
err_dir:
Expand All @@ -61,5 +215,4 @@ static int __init arch_kdebugfs_init(void)

return error;
}

arch_initcall(arch_kdebugfs_init);
24 changes: 24 additions & 0 deletions arch/x86/kernel/setup_64.c
Original file line number Diff line number Diff line change
Expand Up @@ -264,6 +264,28 @@ void __attribute__((weak)) __init memory_setup(void)
machine_specific_memory_setup();
}

static void __init parse_setup_data(void)
{
struct setup_data *data;
unsigned long pa_data;

if (boot_params.hdr.version < 0x0209)
return;
pa_data = boot_params.hdr.setup_data;
while (pa_data) {
data = early_ioremap(pa_data, PAGE_SIZE);
switch (data->type) {
default:
break;
}
#ifndef CONFIG_DEBUG_BOOT_PARAMS
free_early(pa_data, pa_data+sizeof(*data)+data->len);
#endif
pa_data = data->next;
early_iounmap(data, PAGE_SIZE);
}
}

/*
* setup_arch - architecture-specific boot-time initializations
*
Expand Down Expand Up @@ -316,6 +338,8 @@ void __init setup_arch(char **cmdline_p)
strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;

parse_setup_data();

parse_early_param();

#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT
Expand Down
14 changes: 14 additions & 0 deletions include/asm-x86/bootparam.h
Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,17 @@
#include <asm/ist.h>
#include <video/edid.h>

/* setup data types */
#define SETUP_NONE 0

/* extensible setup data list node */
struct setup_data {
u64 next;
u32 type;
u32 len;
u8 data[0];
};

struct setup_header {
__u8 setup_sects;
__u16 root_flags;
Expand Down Expand Up @@ -46,6 +57,9 @@ struct setup_header {
__u32 cmdline_size;
__u32 hardware_subarch;
__u64 hardware_subarch_data;
__u32 payload_offset;
__u32 payload_length;
__u64 setup_data;
} __attribute__((packed));

struct sys_desc_table {
Expand Down
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