efi_loader: implement EFI_DT_FIXUP_PROTOCOL
A boot manager like GRUB can use the protocol to
* apply U-Boot's fix-ups to the a device-tree
* let U-Boot make memory reservations according to the device-tree
* install the device-tree as a configuration table
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/lib/efi_loader/efi_dt_fixup.c b/lib/efi_loader/efi_dt_fixup.c
new file mode 100644
index 0000000..5f0ae5c
--- /dev/null
+++ b/lib/efi_loader/efi_dt_fixup.c
@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * EFI_DT_FIXUP_PROTOCOL
+ *
+ * Copyright (c) 2020 Heinrich Schuchardt
+ */
+
+#include <common.h>
+#include <efi_dt_fixup.h>
+#include <efi_loader.h>
+#include <mapmem.h>
+
+static efi_status_t EFIAPI efi_dt_fixup(struct efi_dt_fixup_protocol *this,
+ void *dtb,
+ efi_uintn_t *buffer_size,
+ u32 flags);
+
+struct efi_dt_fixup_protocol efi_dt_fixup_prot = {
+ .revision = EFI_DT_FIXUP_PROTOCOL_REVISION,
+ .fixup = efi_dt_fixup
+};
+
+const efi_guid_t efi_guid_dt_fixup_protocol = EFI_DT_FIXUP_PROTOCOL_GUID;
+
+/**
+ * efi_reserve_memory() - add reserved memory to memory map
+ *
+ * @addr: start address of the reserved memory range
+ * @size: size of the reserved memory range
+ * @nomap: indicates that the memory range shall not be accessed by the
+ * UEFI payload
+ */
+static void efi_reserve_memory(u64 addr, u64 size, bool nomap)
+{
+ int type;
+ efi_uintn_t ret;
+
+ /* Convert from sandbox address space. */
+ addr = (uintptr_t)map_sysmem(addr, 0);
+
+ if (nomap)
+ type = EFI_RESERVED_MEMORY_TYPE;
+ else
+ type = EFI_BOOT_SERVICES_DATA;
+
+ ret = efi_add_memory_map(addr, size, type);
+ if (ret != EFI_SUCCESS)
+ log_err("Reserved memory mapping failed addr %llx size %llx\n",
+ addr, size);
+}
+
+/**
+ * efi_carve_out_dt_rsv() - Carve out DT reserved memory ranges
+ *
+ * The mem_rsv entries of the FDT are added to the memory map. Any failures are
+ * ignored because this is not critical and we would rather continue to try to
+ * boot.
+ *
+ * @fdt: Pointer to device tree
+ */
+void efi_carve_out_dt_rsv(void *fdt)
+{
+ int nr_rsv, i;
+ u64 addr, size;
+ int nodeoffset, subnode;
+
+ nr_rsv = fdt_num_mem_rsv(fdt);
+
+ /* Look for an existing entry and add it to the efi mem map. */
+ for (i = 0; i < nr_rsv; i++) {
+ if (fdt_get_mem_rsv(fdt, i, &addr, &size) != 0)
+ continue;
+ efi_reserve_memory(addr, size, false);
+ }
+
+ /* process reserved-memory */
+ nodeoffset = fdt_subnode_offset(fdt, 0, "reserved-memory");
+ if (nodeoffset >= 0) {
+ subnode = fdt_first_subnode(fdt, nodeoffset);
+ while (subnode >= 0) {
+ fdt_addr_t fdt_addr;
+ fdt_size_t fdt_size;
+
+ /* check if this subnode has a reg property */
+ fdt_addr = fdtdec_get_addr_size_auto_parent(
+ fdt, nodeoffset, subnode,
+ "reg", 0, &fdt_size, false);
+ /*
+ * The /reserved-memory node may have children with
+ * a size instead of a reg property.
+ */
+ if (fdt_addr != FDT_ADDR_T_NONE &&
+ fdtdec_get_is_enabled(fdt, subnode)) {
+ bool nomap;
+
+ nomap = !!fdt_getprop(fdt, subnode, "no-map",
+ NULL);
+ efi_reserve_memory(fdt_addr, fdt_size, nomap);
+ }
+ subnode = fdt_next_subnode(fdt, subnode);
+ }
+ }
+}
+
+static efi_status_t EFIAPI efi_dt_fixup(struct efi_dt_fixup_protocol *this,
+ void *dtb,
+ efi_uintn_t *buffer_size,
+ u32 flags)
+{
+ efi_status_t ret;
+ size_t required_size;
+ bootm_headers_t img = { 0 };
+
+ EFI_ENTRY("%p, %p, %p, %d", this, dtb, buffer_size, flags);
+
+ if (this != &efi_dt_fixup_prot || !dtb || !buffer_size ||
+ !flags || (flags & ~EFI_DT_ALL)) {
+ ret = EFI_INVALID_PARAMETER;
+ goto out;
+ }
+ if (fdt_check_header(dtb)) {
+ ret = EFI_INVALID_PARAMETER;
+ goto out;
+ }
+ if (flags & EFI_DT_APPLY_FIXUPS) {
+ required_size = fdt_off_dt_strings(dtb) +
+ fdt_size_dt_strings(dtb) +
+ 0x3000;
+ } else {
+ required_size = fdt_totalsize(dtb);
+ }
+ if (required_size > *buffer_size) {
+ *buffer_size = required_size;
+ ret = EFI_BUFFER_TOO_SMALL;
+ goto out;
+ }
+ fdt_set_totalsize(dtb, *buffer_size);
+
+ if (flags & EFI_DT_APPLY_FIXUPS) {
+ if (image_setup_libfdt(&img, dtb, 0, NULL)) {
+ log_err("failed to process device tree\n");
+ ret = EFI_INVALID_PARAMETER;
+ goto out;
+ }
+ }
+ if (flags & EFI_DT_RESERVE_MEMORY)
+ efi_carve_out_dt_rsv(dtb);
+
+ if (EFI_DT_INSTALL_TABLE) {
+ ret = efi_install_configuration_table(&efi_guid_fdt, dtb);
+ if (ret != EFI_SUCCESS) {
+ log_err("ERROR: failed to install device tree\n");
+ goto out;
+ }
+ }
+
+ ret = EFI_SUCCESS;
+out:
+ return EFI_EXIT(ret);
+}