x86, boot: add linked list of struct setup_data

This patch adds a field of 64-bit physical pointer to NULL terminated
single linked list of struct setup_data to real-mode kernel
header. This is used as a more extensible boot parameters passing
mechanism.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index 6d2df8d..af86e43 100644 (file)
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -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
@@ -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"

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index d31d6b7..e25c57b 100644 (file)
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -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>
@@ -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;
@@ -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

diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 17bdf23..e1a21d6 100644 (file)
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -264,6 +264,26 @@ 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;
+               }
+               free_early(pa_data, pa_data+sizeof(*data)+data->len);
+               pa_data = data->next;
+               early_iounmap(data, PAGE_SIZE);
+       }
+}
+
 /*
  * setup_arch - architecture-specific boot-time initializations
  *
@@ -316,6 +336,8 @@ 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

diff --git a/include/asm-x86/bootparam.h b/include/asm-x86/bootparam.h
index 5115135..e865990 100644 (file)
--- a/include/asm-x86/bootparam.h
+++ b/include/asm-x86/bootparam.h
@@ -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;
@@ -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 {