Re: [PATCH] x86,setup: add serial_console_port_base in boot_params

From: Yinghai Lu
Date: Sat Jul 31 2010 - 21:55:56 EST


On 07/31/2010 02:02 PM, H. Peter Anvin wrote:
> On 07/31/2010 11:32 AM, Cyrill Gorcunov wrote:
>>>
>>> No, this is the internal part of the boot protocol, so it's not an issue.
>>>
>>
>> Peter, I didn't mean any issue here, I meant that bootloaders don't know about
>> this field yet and they will have to update own sources to pass port value
>> at proper place of boot params. Or I miss something?
>>
>
> Boot loaders that use the 16-bit entry point are unaffected.
>
> Boot loaders which use the 32-bit entry point but properly clears the
> zero page simply will not have the feature.
>
> Boot loaders which use the 32-bit entry point but doesn't clear the zero
> page are broken.
>
can you if this one is right for kexec path?

Thanks

Yinghai

[PATCH] kexec-tools: pass serial console base for early console in kernel

when kexec is used with "console_serial", set serial_console_port_base in boot_params.

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>

---
doc/linux-i386-zero-page.txt | 1 +
include/x86/x86-linux.h | 3 ++-
kexec/arch/i386/kexec-x86.h | 1 +
kexec/arch/i386/x86-linux-setup.c | 4 ++++
kexec/arch/x86_64/kexec-x86_64.c | 9 +--------
5 files changed, 9 insertions(+), 9 deletions(-)

Index: kexec-tools/doc/linux-i386-zero-page.txt
===================================================================
--- kexec-tools.orig/doc/linux-i386-zero-page.txt
+++ kexec-tools/doc/linux-i386-zero-page.txt
@@ -22,6 +22,7 @@ Offset Type Description
0x90000 + contents of CL_OFFSET
(only taken, when CL_MAGIC = 0xA33F)
0x40 20 bytes struct apm_bios_info, APM_BIOS_INFO
+ 0x54 2 bytes serial console base
0x60 16 bytes Intel SpeedStep (IST) BIOS support information
0x80 16 bytes hd0-disk-parameter from intvector 0x41
0x90 16 bytes hd1-disk-parameter from intvector 0x46
Index: kexec-tools/include/x86/x86-linux.h
===================================================================
--- kexec-tools.orig/include/x86/x86-linux.h
+++ kexec-tools/include/x86/x86-linux.h
@@ -40,7 +40,6 @@ struct apm_bios_info {
uint16_t cseg_len; /* 0x4e */
uint16_t cseg_16_len; /* 0x50 */
uint16_t dseg_len; /* 0x52 */
- uint8_t reserved[44]; /* 0x54 */
};

/*
@@ -105,6 +104,8 @@ struct x86_linux_param_header {
uint8_t reserved4[12]; /* 0x34 -- 0x3f reserved for future expansion */

struct apm_bios_info apm_bios_info; /* 0x40 */
+ uint16_t serial_console_port_base; /* 0x54 */
+ uint8_t reserved41[42]; /* 0x56 */
struct drive_info_struct drive_info; /* 0x80 */
struct sys_desc_table sys_desc_table; /* 0xa0 */
uint32_t alt_mem_k; /* 0x1e0 */
Index: kexec-tools/kexec/arch/i386/x86-linux-setup.c
===================================================================
--- kexec-tools.orig/kexec/arch/i386/x86-linux-setup.c
+++ kexec-tools/kexec/arch/i386/x86-linux-setup.c
@@ -100,6 +100,9 @@ void setup_linux_bootloader_parameters(
cmdline_ptr = ((char *)real_mode) + cmdline_offset;
memcpy(cmdline_ptr, cmdline, cmdline_len);
cmdline_ptr[cmdline_len - 1] = '\0';
+
+ if (arch_options.console_serial)
+ real_mode->serial_console_port_base = arch_options.serial_base;
}

int setup_linux_vesafb(struct x86_linux_param_header *real_mode)
@@ -422,6 +425,7 @@ void setup_linux_system_parameters(struc

/* Default APM info */
memset(&real_mode->apm_bios_info, 0, sizeof(real_mode->apm_bios_info));
+
/* Default drive info */
memset(&real_mode->drive_info, 0, sizeof(real_mode->drive_info));
/* Default sysdesc table */
Index: kexec-tools/kexec/arch/i386/kexec-x86.h
===================================================================
--- kexec-tools.orig/kexec/arch/i386/kexec-x86.h
+++ kexec-tools/kexec/arch/i386/kexec-x86.h
@@ -51,6 +51,7 @@ struct arch_options_t {
uint8_t console_serial;
enum coretype core_header_type;
};
+extern struct arch_options_t arch_options;

int multiboot_x86_probe(const char *buf, off_t len);
int multiboot_x86_load(int argc, char **argv, const char *buf, off_t len,
Index: kexec-tools/kexec/arch/x86_64/kexec-x86_64.c
===================================================================
--- kexec-tools.orig/kexec/arch/x86_64/kexec-x86_64.c
+++ kexec-tools/kexec/arch/x86_64/kexec-x86_64.c
@@ -55,14 +55,7 @@ void arch_usage(void)
);
}

-static struct {
- uint8_t reset_vga;
- uint16_t serial_base;
- uint32_t serial_baud;
- uint8_t console_vga;
- uint8_t console_serial;
- int core_header_type;
-} arch_options = {
+struct arch_options_t arch_options = {
.reset_vga = 0,
.serial_base = 0x3f8,
.serial_baud = 0,
--
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