[PATCH 2/4] x86_64 boot -v2: Add linked list of struct setup_data

From: Huang, Ying
Date: Thu Mar 27 2008 - 22:47:20 EST


This patch add 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@xxxxxxxxx>

---
arch/x86/boot/header.S | 6 +++++-
arch/x86/kernel/head64.c | 20 ++++++++++++++++++++
arch/x86/kernel/setup_64.c | 22 ++++++++++++++++++++++
include/asm-x86/bootparam.h | 14 ++++++++++++++
4 files changed, 61 insertions(+), 1 deletion(-)

--- 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 {
--- 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"
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -265,6 +265,26 @@ void __attribute__((weak)) __init memory
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
*
@@ -317,6 +337,8 @@ 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
--- 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>
@@ -101,6 +102,24 @@ static void __init reserve_ebda_region(v
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;
@@ -157,6 +176,7 @@ void __init x86_64_start_kernel(char * r
#endif

reserve_ebda_region();
+ reserve_setup_data();

/*
* At this point everything still needed from the boot loader

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