sd-boot: add EFI boot manager and stub loader

1 files changed, 130 insertions, 0 deletions

diff --git a/src/sd-boot/linux.c b/src/sd-boot/linux.c
new file mode 100644
index 0000000000..809c69310e
--- /dev/null
+++ b/src/sd-boot/linux.c
@@ -0,0 +1,130 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * 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
+ * Lesser General Public License for more details.
+ *
+ * Copyright (C) 2015 Kay Sievers <kay@vrfy.org>
+ */
+
+#include <efi.h>
+#include <efilib.h>
+
+#include "util.h"
+#include "linux.h"
+
+#define SETUP_MAGIC             0x53726448      /* "HdrS" */
+struct SetupHeader {
+        UINT8 boot_sector[0x01f1];
+        UINT8 setup_secs;
+        UINT16 root_flags;
+        UINT32 sys_size;
+        UINT16 ram_size;
+        UINT16 video_mode;
+        UINT16 root_dev;
+        UINT16 signature;
+        UINT16 jump;
+        UINT32 header;
+        UINT16 version;
+        UINT16 su_switch;
+        UINT16 setup_seg;
+        UINT16 start_sys;
+        UINT16 kernel_ver;
+        UINT8 loader_id;
+        UINT8 load_flags;
+        UINT16 movesize;
+        UINT32 code32_start;
+        UINT32 ramdisk_start;
+        UINT32 ramdisk_len;
+        UINT32 bootsect_kludge;
+        UINT16 heap_end;
+        UINT8 ext_loader_ver;
+        UINT8 ext_loader_type;
+        UINT32 cmd_line_ptr;
+        UINT32 ramdisk_max;
+        UINT32 kernel_alignment;
+        UINT8 relocatable_kernel;
+        UINT8 min_alignment;
+        UINT16 xloadflags;
+        UINT32 cmdline_size;
+        UINT32 hardware_subarch;
+        UINT64 hardware_subarch_data;
+        UINT32 payload_offset;
+        UINT32 payload_length;
+        UINT64 setup_data;
+        UINT64 pref_address;
+        UINT32 init_size;
+        UINT32 handover_offset;
+} __attribute__((packed));
+
+#ifdef __x86_64__
+typedef VOID(*handover_f)(VOID *image, EFI_SYSTEM_TABLE *table, struct SetupHeader *setup);
+static inline VOID linux_efi_handover(EFI_HANDLE image, struct SetupHeader *setup) {
+        handover_f handover;
+
+        asm volatile ("cli");
+        handover = (handover_f)((UINTN)setup->code32_start + 512 + setup->handover_offset);
+        handover(image, ST, setup);
+}
+#else
+typedef VOID(*handover_f)(VOID *image, EFI_SYSTEM_TABLE *table, struct SetupHeader *setup) __attribute__((regparm(0)));
+static inline VOID linux_efi_handover(EFI_HANDLE image, struct SetupHeader *setup) {
+        handover_f handover;
+
+        handover = (handover_f)((UINTN)setup->code32_start + setup->handover_offset);
+        handover(image, ST, setup);
+}
+#endif
+
+EFI_STATUS linux_exec(EFI_HANDLE *image,
+                      CHAR8 *cmdline, UINTN cmdline_len,
+                      UINTN linux_addr,
+                      UINTN initrd_addr, UINTN initrd_size) {
+        struct SetupHeader *image_setup;
+        struct SetupHeader *boot_setup;
+        EFI_PHYSICAL_ADDRESS addr;
+        EFI_STATUS err;
+
+        image_setup = (struct SetupHeader *)(linux_addr);
+        if (image_setup->signature != 0xAA55 || image_setup->header != SETUP_MAGIC)
+                return EFI_LOAD_ERROR;
+
+        if (image_setup->version < 0x20b || !image_setup->relocatable_kernel)
+                return EFI_LOAD_ERROR;
+
+        addr = 0x3fffffff;
+        err = uefi_call_wrapper(BS->AllocatePages, 4, AllocateMaxAddress, EfiLoaderData,
+                                EFI_SIZE_TO_PAGES(0x4000), &addr);
+        if (EFI_ERROR(err))
+                return err;
+        boot_setup = (struct SetupHeader *)(UINTN)addr;
+        ZeroMem(boot_setup, 0x4000);
+        CopyMem(boot_setup, image_setup, sizeof(struct SetupHeader));
+        boot_setup->loader_id = 0xff;
+
+        boot_setup->code32_start = (UINT32)linux_addr + (image_setup->setup_secs+1) * 512;
+
+        if (cmdline) {
+                addr = 0xA0000;
+                err = uefi_call_wrapper(BS->AllocatePages, 4, AllocateMaxAddress, EfiLoaderData,
+                                        EFI_SIZE_TO_PAGES(cmdline_len + 1), &addr);
+                if (EFI_ERROR(err))
+                        return err;
+                CopyMem((VOID *)(UINTN)addr, cmdline, cmdline_len);
+                ((CHAR8 *)addr)[cmdline_len] = 0;
+                boot_setup->cmd_line_ptr = (UINT32)addr;
+        }
+
+        boot_setup->ramdisk_start = (UINT32)initrd_addr;
+        boot_setup->ramdisk_len = (UINT32)initrd_size;
+
+        linux_efi_handover(image, boot_setup);
+        return EFI_LOAD_ERROR;
+}