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-rw-r--r--src/boot/efi/util.c342
1 files changed, 342 insertions, 0 deletions
diff --git a/src/boot/efi/util.c b/src/boot/efi/util.c
new file mode 100644
index 0000000..f1f1674
--- /dev/null
+++ b/src/boot/efi/util.c
@@ -0,0 +1,342 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <efi.h>
+#include <efilib.h>
+
+#include "util.h"
+
+/*
+ * Allocated random UUID, intended to be shared across tools that implement
+ * the (ESP)\loader\entries\<vendor>-<revision>.conf convention and the
+ * associated EFI variables.
+ */
+const EFI_GUID loader_guid = { 0x4a67b082, 0x0a4c, 0x41cf, {0xb6, 0xc7, 0x44, 0x0b, 0x29, 0xbb, 0x8c, 0x4f} };
+
+#ifdef __x86_64__
+UINT64 ticks_read(VOID) {
+ UINT64 a, d;
+ __asm__ volatile ("rdtsc" : "=a" (a), "=d" (d));
+ return (d << 32) | a;
+}
+#elif defined(__i386__)
+UINT64 ticks_read(VOID) {
+ UINT64 val;
+ __asm__ volatile ("rdtsc" : "=A" (val));
+ return val;
+}
+#else
+UINT64 ticks_read(VOID) {
+ UINT64 val = 1;
+ return val;
+}
+#endif
+
+/* count TSC ticks during a millisecond delay */
+UINT64 ticks_freq(VOID) {
+ UINT64 ticks_start, ticks_end;
+
+ ticks_start = ticks_read();
+ uefi_call_wrapper(BS->Stall, 1, 1000);
+ ticks_end = ticks_read();
+
+ return (ticks_end - ticks_start) * 1000UL;
+}
+
+UINT64 time_usec(VOID) {
+ UINT64 ticks;
+ static UINT64 freq;
+
+ ticks = ticks_read();
+ if (ticks == 0)
+ return 0;
+
+ if (freq == 0) {
+ freq = ticks_freq();
+ if (freq == 0)
+ return 0;
+ }
+
+ return 1000UL * 1000UL * ticks / freq;
+}
+
+EFI_STATUS parse_boolean(const CHAR8 *v, BOOLEAN *b) {
+ if (!v)
+ return EFI_INVALID_PARAMETER;
+
+ if (strcmpa(v, (CHAR8 *)"1") == 0 ||
+ strcmpa(v, (CHAR8 *)"yes") == 0 ||
+ strcmpa(v, (CHAR8 *)"y") == 0 ||
+ strcmpa(v, (CHAR8 *)"true") == 0) {
+ *b = TRUE;
+ return EFI_SUCCESS;
+ }
+
+ if (strcmpa(v, (CHAR8 *)"0") == 0 ||
+ strcmpa(v, (CHAR8 *)"no") == 0 ||
+ strcmpa(v, (CHAR8 *)"n") == 0 ||
+ strcmpa(v, (CHAR8 *)"false") == 0) {
+ *b = FALSE;
+ return EFI_SUCCESS;
+ }
+
+ return EFI_INVALID_PARAMETER;
+}
+
+EFI_STATUS efivar_set_raw(const EFI_GUID *vendor, const CHAR16 *name, const VOID *buf, UINTN size, BOOLEAN persistent) {
+ UINT32 flags;
+
+ flags = EFI_VARIABLE_BOOTSERVICE_ACCESS|EFI_VARIABLE_RUNTIME_ACCESS;
+ if (persistent)
+ flags |= EFI_VARIABLE_NON_VOLATILE;
+
+ return uefi_call_wrapper(RT->SetVariable, 5, (CHAR16*) name, (EFI_GUID *)vendor, flags, size, (VOID*) buf);
+}
+
+EFI_STATUS efivar_set(const CHAR16 *name, const CHAR16 *value, BOOLEAN persistent) {
+ return efivar_set_raw(&loader_guid, name, value, value ? (StrLen(value)+1) * sizeof(CHAR16) : 0, persistent);
+}
+
+EFI_STATUS efivar_set_int(CHAR16 *name, UINTN i, BOOLEAN persistent) {
+ CHAR16 str[32];
+
+ SPrint(str, 32, L"%u", i);
+ return efivar_set(name, str, persistent);
+}
+
+EFI_STATUS efivar_get(const CHAR16 *name, CHAR16 **value) {
+ _cleanup_freepool_ CHAR8 *buf = NULL;
+ EFI_STATUS err;
+ CHAR16 *val;
+ UINTN size;
+
+ err = efivar_get_raw(&loader_guid, name, &buf, &size);
+ if (EFI_ERROR(err))
+ return err;
+
+ /* Make sure there are no incomplete characters in the buffer */
+ if ((size % 2) != 0)
+ return EFI_INVALID_PARAMETER;
+
+ /* Return buffer directly if it happens to be NUL terminated already */
+ if (size >= 2 && buf[size-2] == 0 && buf[size-1] == 0) {
+ *value = (CHAR16*) buf;
+ buf = NULL;
+ return EFI_SUCCESS;
+ }
+
+ /* Make sure a terminating NUL is available at the end */
+ val = AllocatePool(size + 2);
+ if (!val)
+ return EFI_OUT_OF_RESOURCES;
+
+ CopyMem(val, buf, size);
+ val[size/2] = 0; /* NUL terminate */
+
+ *value = val;
+ return EFI_SUCCESS;
+}
+
+EFI_STATUS efivar_get_int(const CHAR16 *name, UINTN *i) {
+ _cleanup_freepool_ CHAR16 *val = NULL;
+ EFI_STATUS err;
+
+ err = efivar_get(name, &val);
+ if (!EFI_ERROR(err))
+ *i = Atoi(val);
+
+ return err;
+}
+
+EFI_STATUS efivar_get_raw(const EFI_GUID *vendor, const CHAR16 *name, CHAR8 **buffer, UINTN *size) {
+ _cleanup_freepool_ CHAR8 *buf = NULL;
+ UINTN l;
+ EFI_STATUS err;
+
+ l = sizeof(CHAR16 *) * EFI_MAXIMUM_VARIABLE_SIZE;
+ buf = AllocatePool(l);
+ if (!buf)
+ return EFI_OUT_OF_RESOURCES;
+
+ err = uefi_call_wrapper(RT->GetVariable, 5, (CHAR16*) name, (EFI_GUID *)vendor, NULL, &l, buf);
+ if (!EFI_ERROR(err)) {
+ *buffer = buf;
+ buf = NULL;
+ if (size)
+ *size = l;
+ }
+
+ return err;
+}
+
+VOID efivar_set_time_usec(CHAR16 *name, UINT64 usec) {
+ CHAR16 str[32];
+
+ if (usec == 0)
+ usec = time_usec();
+ if (usec == 0)
+ return;
+
+ SPrint(str, 32, L"%ld", usec);
+ efivar_set(name, str, FALSE);
+}
+
+static INTN utf8_to_16(CHAR8 *stra, CHAR16 *c) {
+ CHAR16 unichar;
+ UINTN len;
+ UINTN i;
+
+ if (stra[0] < 0x80)
+ len = 1;
+ else if ((stra[0] & 0xe0) == 0xc0)
+ len = 2;
+ else if ((stra[0] & 0xf0) == 0xe0)
+ len = 3;
+ else if ((stra[0] & 0xf8) == 0xf0)
+ len = 4;
+ else if ((stra[0] & 0xfc) == 0xf8)
+ len = 5;
+ else if ((stra[0] & 0xfe) == 0xfc)
+ len = 6;
+ else
+ return -1;
+
+ switch (len) {
+ case 1:
+ unichar = stra[0];
+ break;
+ case 2:
+ unichar = stra[0] & 0x1f;
+ break;
+ case 3:
+ unichar = stra[0] & 0x0f;
+ break;
+ case 4:
+ unichar = stra[0] & 0x07;
+ break;
+ case 5:
+ unichar = stra[0] & 0x03;
+ break;
+ case 6:
+ unichar = stra[0] & 0x01;
+ break;
+ }
+
+ for (i = 1; i < len; i++) {
+ if ((stra[i] & 0xc0) != 0x80)
+ return -1;
+ unichar <<= 6;
+ unichar |= stra[i] & 0x3f;
+ }
+
+ *c = unichar;
+ return len;
+}
+
+CHAR16 *stra_to_str(CHAR8 *stra) {
+ UINTN strlen;
+ UINTN len;
+ UINTN i;
+ CHAR16 *str;
+
+ len = strlena(stra);
+ str = AllocatePool((len + 1) * sizeof(CHAR16));
+
+ strlen = 0;
+ i = 0;
+ while (i < len) {
+ INTN utf8len;
+
+ utf8len = utf8_to_16(stra + i, str + strlen);
+ if (utf8len <= 0) {
+ /* invalid utf8 sequence, skip the garbage */
+ i++;
+ continue;
+ }
+
+ strlen++;
+ i += utf8len;
+ }
+ str[strlen] = '\0';
+ return str;
+}
+
+CHAR16 *stra_to_path(CHAR8 *stra) {
+ CHAR16 *str;
+ UINTN strlen;
+ UINTN len;
+ UINTN i;
+
+ len = strlena(stra);
+ str = AllocatePool((len + 2) * sizeof(CHAR16));
+
+ str[0] = '\\';
+ strlen = 1;
+ i = 0;
+ while (i < len) {
+ INTN utf8len;
+
+ utf8len = utf8_to_16(stra + i, str + strlen);
+ if (utf8len <= 0) {
+ /* invalid utf8 sequence, skip the garbage */
+ i++;
+ continue;
+ }
+
+ if (str[strlen] == '/')
+ str[strlen] = '\\';
+ if (str[strlen] == '\\' && str[strlen-1] == '\\') {
+ /* skip double slashes */
+ i += utf8len;
+ continue;
+ }
+
+ strlen++;
+ i += utf8len;
+ }
+ str[strlen] = '\0';
+ return str;
+}
+
+CHAR8 *strchra(CHAR8 *s, CHAR8 c) {
+ do {
+ if (*s == c)
+ return s;
+ } while (*s++);
+ return NULL;
+}
+
+EFI_STATUS file_read(EFI_FILE_HANDLE dir, const CHAR16 *name, UINTN off, UINTN size, CHAR8 **content, UINTN *content_size) {
+ EFI_FILE_HANDLE handle;
+ _cleanup_freepool_ CHAR8 *buf = NULL;
+ EFI_STATUS err;
+
+ err = uefi_call_wrapper(dir->Open, 5, dir, &handle, (CHAR16*) name, EFI_FILE_MODE_READ, 0ULL);
+ if (EFI_ERROR(err))
+ return err;
+
+ if (size == 0) {
+ _cleanup_freepool_ EFI_FILE_INFO *info;
+
+ info = LibFileInfo(handle);
+ size = info->FileSize+1;
+ }
+
+ if (off > 0) {
+ err = uefi_call_wrapper(handle->SetPosition, 2, handle, off);
+ if (EFI_ERROR(err))
+ return err;
+ }
+
+ buf = AllocatePool(size + 1);
+ err = uefi_call_wrapper(handle->Read, 3, handle, &size, buf);
+ if (!EFI_ERROR(err)) {
+ buf[size] = '\0';
+ *content = buf;
+ buf = NULL;
+ if (content_size)
+ *content_size = size;
+ }
+ uefi_call_wrapper(handle->Close, 1, handle);
+
+ return err;
+}