coreboot-kgpe-d16/util/cbfstool/linux.h

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/*
* This file is part of coreboot..
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
/*
* Linux/i386 loader
* Supports bzImage, zImage and Image format.
*
* Based on work by Steve Gehlbach.
* Portions are taken from mkelfImage.
*
* 2003-09 by SONE Takeshi
*/
#include <stdint.h>
cbfstool:linux_trampoline: config CS and DS segment descriptors The Linux trampoline code does not set up the segment descriptors for __BOOT_CS and __BOOT_DS as described in the Linux kernel documentation: ... a GDT must be loaded with the descriptors for selectors __BOOT_CS(0x10) and __BOOT_DS(0x18); both descriptors must be 4G flat segment; __BOOT_CS must have execute/read permission, and __BOOT_DS must have read/write permission; This is not a problem when launching a Linux payload from coreboot, as coreboot configures the segment descriptors at selectors 0x10 and 0x18. Coreboot configures these selectors in the ramstage to match what the Linux kernel expects (see coreboot/src/arch/x86/lib/c_start.S). When the cbfs payload is launched in other environments, SeaBIOS for example, the segment descriptors are configured differently and the cbfs Linux payload does not work. If the cbfs Linux payload is to be used in multiple environments should the trampoline needs to take care of the descriptors that Linux requires. This patch updates the Linux trampoline code to configure the 4G flat descriptors that Linux expects. The configuration is borrowed from the descriptor configs in coreboot/src/arch/x86/lib/c_start.S for selectors 0x10 and 0x18. The linux_trampoline code is slightly refractored by defining the trampoline entry address, 0x40000, as TRAMPOLINE_ENTRY_LOC. This definition is moved into a separate header file, linux_trampoline.h. This header file is now included by both the trampoline assembly language code and the trampoline loader C code. The trampoline assembly language code can now use TRAMPOLINE_ENTRY_LOC as scratch space for the sgdt CPU instruction. Testing Done: Verified the Linux payload is booted correctly in the following environments: 1. Coreboot -> Linux Payload 2. Coreboot -> SeaBIOS -> Linux Payload: (previously did not work) Change-Id: I888f74ff43073a6b7318f6713a8d4ecb804c0162 Signed-off-by: Curt Brune <curt@cumulusnetworks.com> Reviewed-on: http://review.coreboot.org/6796 Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net> Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
2014-08-29 19:43:36 +02:00
#include "linux_trampoline.h"
typedef uint8_t u8;
typedef uint16_t u16;
typedef uint32_t u32;
typedef uint64_t u64;
#define E820MAX 32 /* number of entries in E820MAP */
struct e820entry {
u64 addr; /* start of memory segment */
u64 size; /* size of memory segment */
u32 type; /* type of memory segment */
#define E820_RAM 1
#define E820_RESERVED 2
#define E820_ACPI 3 /* usable as RAM once ACPI tables have been read */
#define E820_NVS 4
};
/* The header of Linux/i386 kernel */
struct linux_header {
u8 reserved1[0x1f1]; /* 0x000 */
u8 setup_sects; /* 0x1f1 */
u16 root_flags; /* 0x1f2 */
u32 syssize; /* 0x1f4 (2.04+) */
u8 reserved2[2]; /* 0x1f8 */
u16 vid_mode; /* 0x1fa */
u16 root_dev; /* 0x1fc */
u16 boot_sector_magic; /* 0x1fe */
/* 2.00+ */
u8 reserved3[2]; /* 0x200 */
u8 header_magic[4]; /* 0x202 */
u16 protocol_version; /* 0x206 */
u32 realmode_swtch; /* 0x208 */
u16 start_sys; /* 0x20c */
u16 kver_addr; /* 0x20e */
u8 type_of_loader; /* 0x210 */
u8 loadflags; /* 0x211 */
u16 setup_move_size; /* 0x212 */
u32 code32_start; /* 0x214 */
u32 ramdisk_image; /* 0x218 */
u32 ramdisk_size; /* 0x21c */
u8 reserved4[4]; /* 0x220 */
/* 2.01+ */
u16 heap_end_ptr; /* 0x224 */
u8 reserved5[2]; /* 0x226 */
/* 2.02+ */
u32 cmd_line_ptr; /* 0x228 */
/* 2.03+ */
u32 initrd_addr_max; /* 0x22c */
/* 2.05+ */
u32 kernel_alignment; /* 0x230 */
u8 relocatable_kernel; /* 0x234 */
u8 min_alignment; /* 0x235 (2.10+) */
u8 reserved6[2]; /* 0x236 */
/* 2.06+ */
u32 cmdline_size; /* 0x238 */
/* 2.07+ */
u32 hardware_subarch; /* 0x23c */
u64 hardware_subarch_data;/* 0x240 */
/* 2.08+ */
u32 payload_offset; /* 0x248 */
u32 payload_length; /* 0x24c */
/* 2.09+ */
u64 setup_data; /* 0x250 */
/* 2.10+ */
u64 pref_address; /* 0x258 */
u32 init_size; /* 0x260 */
} __attribute__ ((packed));
/* Paramters passed to 32-bit part of Linux
* This is another view of the structure above.. */
struct linux_params {
u8 orig_x; /* 0x00 */
u8 orig_y; /* 0x01 */
u16 ext_mem_k; /* 0x02 -- EXT_MEM_K sits here */
u16 orig_video_page; /* 0x04 */
u8 orig_video_mode; /* 0x06 */
u8 orig_video_cols; /* 0x07 */
u16 unused2; /* 0x08 */
u16 orig_video_ega_bx; /* 0x0a */
u16 unused3; /* 0x0c */
u8 orig_video_lines; /* 0x0e */
u8 orig_video_isVGA; /* 0x0f */
u16 orig_video_points; /* 0x10 */
/* VESA graphic mode -- linear frame buffer */
u16 lfb_width; /* 0x12 */
u16 lfb_height; /* 0x14 */
u16 lfb_depth; /* 0x16 */
u32 lfb_base; /* 0x18 */
u32 lfb_size; /* 0x1c */
u16 cl_magic; /* 0x20 */
#define CL_MAGIC_VALUE 0xA33F
u16 cl_offset; /* 0x22 */
u16 lfb_linelength; /* 0x24 */
u8 red_size; /* 0x26 */
u8 red_pos; /* 0x27 */
u8 green_size; /* 0x28 */
u8 green_pos; /* 0x29 */
u8 blue_size; /* 0x2a */
u8 blue_pos; /* 0x2b */
u8 rsvd_size; /* 0x2c */
u8 rsvd_pos; /* 0x2d */
u16 vesapm_seg; /* 0x2e */
u16 vesapm_off; /* 0x30 */
u16 pages; /* 0x32 */
u8 reserved4[12]; /* 0x34 -- 0x3f reserved for future expansion */
//struct apm_bios_info apm_bios_info; /* 0x40 */
u8 apm_bios_info[0x40];
//struct drive_info_struct drive_info; /* 0x80 */
u8 drive_info[0x20];
//struct sys_desc_table sys_desc_table; /* 0xa0 */
u8 sys_desc_table[0x140];
u32 alt_mem_k; /* 0x1e0 */
u8 reserved5[4]; /* 0x1e4 */
u8 e820_map_nr; /* 0x1e8 */
u8 reserved6[9]; /* 0x1e9 */
u16 mount_root_rdonly; /* 0x1f2 */
u8 reserved7[4]; /* 0x1f4 */
u16 ramdisk_flags; /* 0x1f8 */
#define RAMDISK_IMAGE_START_MASK 0x07FF
#define RAMDISK_PROMPT_FLAG 0x8000
#define RAMDISK_LOAD_FLAG 0x4000
u8 reserved8[2]; /* 0x1fa */
u16 orig_root_dev; /* 0x1fc */
u8 reserved9[1]; /* 0x1fe */
u8 aux_device_info; /* 0x1ff */
u8 reserved10[2]; /* 0x200 */
u8 param_block_signature[4]; /* 0x202 */
u16 param_block_version; /* 0x206 */
u8 reserved11[8]; /* 0x208 */
u8 loader_type; /* 0x210 */
#define LOADER_TYPE_LOADLIN 1
#define LOADER_TYPE_BOOTSECT_LOADER 2
#define LOADER_TYPE_SYSLINUX 3
#define LOADER_TYPE_ETHERBOOT 4
#define LOADER_TYPE_KERNEL 5
u8 loader_flags; /* 0x211 */
u8 reserved12[2]; /* 0x212 */
u32 kernel_start; /* 0x214 */
u32 initrd_start; /* 0x218 */
u32 initrd_size; /* 0x21c */
u8 reserved12_5[8]; /* 0x220 */
u32 cmd_line_ptr; /* 0x228 */
u32 initrd_addr_max; /* 0x22c */
u32 kernel_alignment; /* 0x230 */
u8 relocatable_kernel; /* 0x234 */
u8 reserved13[155]; /* 0x22c */
struct e820entry e820_map[E820MAX]; /* 0x2d0 */
u8 reserved16[688]; /* 0x550 */
#define COMMAND_LINE_SIZE 256
/* Command line is copied here by 32-bit i386/kernel/head.S.
* So I will follow the boot protocol, rather than putting it
* directly here. --ts1 */
u8 command_line[COMMAND_LINE_SIZE]; /* 0x800 */
u8 reserved17[1792]; /* 0x900 - 0x1000 */
};