Re: [RFC][PATCH 1/1] x86, efi: EFI boot stub config file support
From: Shea Levy
Date: Sun Mar 18 2012 - 11:49:25 EST
This is a multi-part message in MIME format.On 3/18/12 11:45 AM, Shea Levy wrote:
Hello,
Inlined is a patch to have the kernel read its parameters from a
config file when booted via the EFI boot stub without any parameters
passed. This patch roughly follows the plan I discussed when proposing
this idea, except now the file is found relative to the location of
the bzImage and there is no additional check to see if
image->parent_handle is NULL (despite the spec saying it will be NULL
when the image was loaded by the firmware itself, it was never NULL on
any of the systems I tested).
Cheers,
Shea Levy
---
From 2c12b0f49831d2d96b6bdcef931794178312c288 Mon Sep 17 00:00:00 2001
From: Shea Levy <shea@xxxxxxxxxxxx>
Date: Sun, 18 Mar 2012 16:17:04 +0100
Subject: [PATCH 1/1] x86, efi: EFI boot stub config file support
When booting via the EFI boot stub, search for a file named
'linux.conf' in
the same directory as the bzImage and read the kernel command line
from it
when no load options are passed.
The file search should only be triggered when the bzImage is loaded
from the
firmware's boot process. When loaded via an EFI shell, the load
options always
contain at least one character, even if no parameters were passed at the
prompt.
Signed-off-by: Shea Levy <shea@xxxxxxxxxxxx>
---
arch/x86/boot/compressed/eboot.c | 146
++++++++++++++++++++++++++++++++++++--
arch/x86/boot/compressed/eboot.h | 2 +
2 files changed, 143 insertions(+), 5 deletions(-)
diff --git a/arch/x86/boot/compressed/eboot.c
b/arch/x86/boot/compressed/eboot.c
index fec216f..672ecfe 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -486,14 +486,14 @@ struct initrd {
* kernel image.
*/
static efi_status_t handle_ramdisks(efi_loaded_image_t *image,
- struct setup_header *hdr)
+ struct setup_header *hdr,
+ efi_file_handle_t *fh)
{
struct initrd *initrds;
unsigned long initrd_addr;
efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
u64 initrd_total;
efi_file_io_interface_t *io;
- efi_file_handle_t *fh;
efi_status_t status;
int nr_initrds;
char *str;
@@ -568,7 +568,7 @@ static efi_status_t
handle_ramdisks(efi_loaded_image_t *image,
*p = '\0';
/* Only open the volume once. */
- if (!i) {
+ if (!fh) {
efi_boot_services_t *boottime;
boottime = sys_table->boottime;
@@ -712,6 +712,7 @@ static efi_status_t make_boot_params(struct
boot_params *boot_params,
u16 *s2;
u8 *s1;
int i;
+ efi_file_handle_t *fh = NULL;
hdr->type_of_loader = 0x21;
@@ -743,14 +744,149 @@ static efi_status_t make_boot_params(struct
boot_params *boot_params,
*s1 = '\0';
}
- }
+ } else {
+ efi_char16_t config_file_name[
+ sizeof CONFIG_FILE_NAME * sizeof(efi_char16_t)];
+ u16 *file_path = (u16 *)image->file_path;
+ efi_char16_t config_path[256], *config_path_position;
+ efi_boot_services_t *boottime;
+ efi_file_info_t *info;
+ unsigned long info_sz = 0;
+ u64 file_sz;
+ efi_guid_t info_guid = EFI_FILE_INFO_ID;
+ efi_guid_t fs_proto = EFI_FILE_SYSTEM_GUID;
+ efi_file_io_interface_t *io;
+ efi_file_handle_t *h;
+
+ boottime = sys_table->boottime;
+
+ config_path_position = config_path;
+
+ for (i = 0; i < sizeof CONFIG_FILE_NAME; i++)
+ config_file_name[i] = CONFIG_FILE_NAME[i];
+
+ while (*file_path == 0x404) {
+ u16 node_size = *(file_path + 1)/sizeof *file_path;
+
+ if (config_path_position - config_path) {
+ if (*(file_path + 2) == '\\' &&
+ *(file_path - 2) == '\\') {
+ config_path_position--;
+ } else if (*(file_path + 2) != '\\' &&
+ *(file_path - 2) != '\\') {
+ *config_path_position++ = '\\';
+ }
+ }
+
+ if ((config_path_position - config_path) + node_size - 3
+ + sizeof config_file_name
+ / sizeof *config_file_name
+ > sizeof config_path
+ / sizeof *config_path)
+ goto end;
+
+ memcpy((void *)config_path_position, file_path + 2,
+ (node_size - 3) * sizeof *config_path);
+ config_path_position += node_size - 3;
+ file_path += node_size;
+ }
+
+ while (*config_path_position != '\\' && config_path_position !=
+ config_path)
+ config_path_position--;
+
+ *config_path_position = '\\';
+
+ memcpy((void *)(config_path_position + 1),
+ config_file_name,
+ sizeof config_file_name);
+
+ status = efi_call_phys3(boottime->handle_protocol,
+ image->device_handle, &fs_proto, &io);
+
+ if (status != EFI_SUCCESS)
+ goto end;
+
+ status = efi_call_phys2(io->open_volume, io, &fh);
+
+ if (status != EFI_SUCCESS) {
+ fh = NULL;
+ goto end;
+ }
+
+ status = efi_call_phys5(fh->open,
+ fh,
+ &h,
+ config_path,
+ EFI_FILE_MODE_READ, (u64)0);
+
+ if (status != EFI_SUCCESS)
+ goto end;
+
+ status = efi_call_phys4(h->get_info, h, &info_guid,
+ &info_sz, NULL);
+
+ if (status != EFI_BUFFER_TOO_SMALL)
+ goto close_config_file;
+
+ while (status == EFI_BUFFER_TOO_SMALL) {
+ status = efi_call_phys3(boottime->allocate_pool,
+ EFI_LOADER_DATA, info_sz, &info);
+
+ if (status != EFI_SUCCESS)
+ goto close_config_file;
+
+ status = efi_call_phys4(h->get_info, h, &info_guid,
+ &info_sz, info);
+
+ if (status == EFI_BUFFER_TOO_SMALL)
+ efi_call_phys1(boottime->free_pool, info);
+ }
+
+ if (status != EFI_SUCCESS)
+ goto free_config_file_info;
+
+ file_sz = info->file_size;
+
+ if (file_sz > hdr->cmdline_size)
+ file_sz = hdr->cmdline_size;
+
+ options_size = file_sz + 1;
+
+ status = low_alloc(options_size, 1, &cmdline);
+
+ if (status != EFI_SUCCESS)
+ goto free_config_file_info;
+
+ status = efi_call_phys3(h->read, h, &file_sz, cmdline);
+
+ if (status != EFI_SUCCESS)
+ goto free_config_file_cmdline;
+
+ *((u8 *)cmdline + file_sz) = 0;
+
+ goto free_config_file_info;
+free_config_file_cmdline:
+ low_free(options_size, cmdline);
+ cmdline = 0;
+ options_size = 0;
+free_config_file_info:
+ efi_call_phys1(boottime->free_pool, info);
+close_config_file:
+ efi_call_phys1(h->close, h);
+ }
+end:
hdr->cmd_line_ptr = cmdline;
hdr->ramdisk_image = 0;
hdr->ramdisk_size = 0;
- status = handle_ramdisks(image, hdr);
+ status = handle_ramdisks(image, hdr, fh);
+
+ if (fh)
+ efi_call_phys1(fh->close, fh);
+
if (status != EFI_SUCCESS)
goto free_cmdline;
diff --git a/arch/x86/boot/compressed/eboot.h
b/arch/x86/boot/compressed/eboot.h
index 3925166..186b4c6 100644
--- a/arch/x86/boot/compressed/eboot.h
+++ b/arch/x86/boot/compressed/eboot.h
@@ -20,6 +20,8 @@
#define PIXEL_BLT_ONLY 3
#define PIXEL_FORMAT_MAX 4
+#define CONFIG_FILE_NAME "linux.conf"
+
struct efi_pixel_bitmask {
u32 red_mask;
u32 green_mask;
Hmm, my mail client seems to have mangled the patch. I've attached it here.