Re: [PATCH] add some EFI device smarts

Bjorn Helgaas
2004-04-21T12:59:22Z

On Tuesday 20 April 2004 5:50 pm, Matt Domsch wrote:
> Matt T. had done the work to move it under drivers/efi, though now
> that there's a drivers/firmware, that's more appropraite.

Sounds good. I'll let Matt T. worry about that for now.

> > + /* Convert Unicode to normal chars */
> > + for (i = 0; i < (name_size/sizeof(name_unicode[0])); i++)
> > + name_utf8[i] = name_unicode[i] & 0xff;
> > + name_utf8[i] = 0;
>
> I've never had a clear understanding of this. It's not really UTF8
> (else straight ASCII text could be used), but more like UCS2.

I don't understand Unicode either. Maybe the attached is a little
closer? The EFI spec (1.10, table 2-2) says strings are stored in
UTF-16, and I think that UTF-16 is the same as ASCII for
(0 < c <= 0x7f).

I also stuck in the GUID stuff and removed the typedef (I prefer
the plain structs myself, but was just following the existing style ;-)).

Oh, BTW, my changes are in efi.c, not efivars.c, so no Kconfig
or modular build implications.

I'll try to post the patch that calls efi_uart_console_only() today.
I just didn't want these EFI changes to get buried in the rest of
that. Thanks a lot for the feedback!

Bjorn

=== arch/ia64/kernel/efi.c 1.31 vs edited ==--- 1.31/arch/ia64/kernel/efi.c Mon Apr 12 04:21:11 2004
+++ edited/arch/ia64/kernel/efi.c Wed Apr 21 06:31:33 2004
@@ -747,6 +747,72 @@
return 0;
}

+int
+efi_get_variable(char *name, efi_guid_t guid, unsigned char *data,
+ unsigned long *size, u32 *attributes)
+{
+ efi_status_t status;
+ efi_guid_t vendor_guid;
+ efi_char16_t name_utf16[128];
+ char name_ascii[ARRAY_SIZE(name_utf16) + 1];
+ unsigned long name_size;
+ int i;
+
+ memset(name_utf16, 0, sizeof(name_utf16));
+ for (;;) {
+ name_size = sizeof(name_utf16);
+ status = efi.get_next_variable(&name_size, name_utf16,
+ &vendor_guid);
+ if (status != EFI_SUCCESS)
+ return -EINVAL;
+
+ /* Convert UTF-16 to ASCII */
+ for (i = 0; i < (name_size/sizeof(name_utf16[0])); i++)
+ name_ascii[i] = name_utf16[i] & 0x7f;
+ name_ascii[i] = 0;
+
+ if (strcmp(name_ascii, name) || efi_guidcmp(guid, vendor_guid))
+ continue;
+
+ status = efi.get_variable(name_utf16, &guid, attributes,
+ size, data);
+ if (status != EFI_SUCCESS)
+ return -EINVAL;
+
+ return 0;
+ }
+}
+
+int __init
+efi_uart_console_only(void)
+{
+ unsigned char data[1024];
+ unsigned long size = sizeof(data);
+ struct efi_generic_dev_path *hdr, *end_addr;
+ int uart = 0;
+
+ if (efi_get_variable("ConOut", EFI_GLOBAL_VARIABLE_GUID, data, &size, NULL) < 0)
+ return 0;
+
+ hdr = (struct efi_generic_dev_path *) data;
+ end_addr = (struct efi_generic_dev_path *) ((u8 *) data + size);
+ while (hdr < end_addr) {
+ if (hdr->type = EFI_DEV_MSG &&
+ hdr->sub_type = EFI_DEV_MSG_UART)
+ uart = 1;
+ else if (hdr->type = EFI_DEV_END_PATH ||
+ hdr->type = EFI_DEV_END_PATH2) {
+ if (!uart)
+ return 0;
+ if (hdr->sub_type = EFI_DEV_END_ENTIRE)
+ return 1;
+ uart = 0;
+ }
+ hdr = (struct efi_generic_dev_path *) ((u8 *) hdr + hdr->length);
+ }
+ return 0; /* malformed path (no end) */
+}
+
static void __exit
efivars_exit (void)
{
=== arch/ia64/kernel/efivars.c 1.15 vs edited ==--- 1.15/arch/ia64/kernel/efivars.c Tue Feb 10 19:51:27 2004
+++ edited/arch/ia64/kernel/efivars.c Wed Apr 21 06:41:25 2004
@@ -191,10 +191,9 @@
variable_name_size);
memcpy(&(new_efivar->var.VendorGuid), vendor_guid, sizeof(efi_guid_t));

- /* Convert Unicode to normal chars (assume top bits are 0),
- ala UTF-8 */
+ /* Convert UTF-16 to ASCII (assume top bits are 0) */
for (i=0; i< (int) (variable_name_size / sizeof(efi_char16_t)); i++) {
- short_name[i] = variable_name[i] & 0xFF;
+ short_name[i] = variable_name[i] & 0x7F;
}

/* This is ugly, but necessary to separate one vendor's
=== include/linux/efi.h 1.7 vs edited ==--- 1.7/include/linux/efi.h Tue Feb 3 22:29:14 2004
+++ edited/include/linux/efi.h Wed Apr 21 06:25:22 2004
@@ -212,6 +212,9 @@
#define UGA_IO_PROTOCOL_GUID \
EFI_GUID( 0x61a4d49e, 0x6f68, 0x4f1b, 0xb9, 0x22, 0xa8, 0x6e, 0xed, 0xb, 0x7, 0xa2 )

+#define EFI_GLOBAL_VARIABLE_GUID \
+ EFI_GUID( 0x8be4df61, 0x93ca, 0x11d2, 0xaa, 0x0d, 0x00, 0xe0, 0x98, 0x03, 0x2b, 0x8c )
+
typedef struct {
efi_guid_t guid;
unsigned long table;
@@ -294,6 +297,8 @@
extern u64 efi_get_iobase (void);
extern u32 efi_mem_type (unsigned long phys_addr);
extern u64 efi_mem_attributes (unsigned long phys_addr);
+extern int efi_get_variable (char *name, efi_guid_t guid, unsigned char *data, unsigned long *size, u32 *attributes);
+extern int __init efi_uart_console_only (void);
extern void efi_initialize_iomem_resources(struct resource *code_resource,
struct resource *data_resource);
extern efi_status_t phys_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc);
@@ -322,6 +327,49 @@
#define EFI_VARIABLE_BOOTSERVICE_ACCESS 0x0000000000000002
#define EFI_VARIABLE_RUNTIME_ACCESS 0x0000000000000004

+/*
+ * EFI Device Path information
+ */
+#define EFI_DEV_HW 0x01
+#define EFI_DEV_PCI 1
+#define EFI_DEV_PCCARD 2
+#define EFI_DEV_MEM_MAPPED 3
+#define EFI_DEV_VENDOR 4
+#define EFI_DEV_CONTROLLER 5
+#define EFI_DEV_ACPI 0x02
+#define EFI_DEV_BASIC_ACPI 1
+#define EFI_DEV_EXPANDED_ACPI 2
+#define EFI_DEV_MSG 0x03
+#define EFI_DEV_MSG_ATAPI 1
+#define EFI_DEV_MSG_SCSI 2
+#define EFI_DEV_MSG_FC 3
+#define EFI_DEV_MSG_1394 4
+#define EFI_DEV_MSG_USB 5
+#define EFI_DEV_MSG_USB_CLASS 15
+#define EFI_DEV_MSG_I20 6
+#define EFI_DEV_MSG_MAC 11
+#define EFI_DEV_MSG_IPV4 12
+#define EFI_DEV_MSG_IPV6 13
+#define EFI_DEV_MSG_INFINIBAND 9
+#define EFI_DEV_MSG_UART 14
+#define EFI_DEV_MSG_VENDOR 10
+#define EFI_DEV_MEDIA 0x04
+#define EFI_DEV_MEDIA_HARD_DRIVE 1
+#define EFI_DEV_MEDIA_CDROM 2
+#define EFI_DEV_MEDIA_VENDOR 3
+#define EFI_DEV_MEDIA_FILE 4
+#define EFI_DEV_MEDIA_PROTOCOL 5
+#define EFI_DEV_BIOS_BOOT 0x05
+#define EFI_DEV_END_PATH 0x7F
+#define EFI_DEV_END_PATH2 0xFF
+#define EFI_DEV_END_INSTANCE 0x01
+#define EFI_DEV_END_ENTIRE 0xFF
+
+struct efi_generic_dev_path {
+ u8 type;
+ u8 sub_type;
+ u16 length;
+} __attribute ((packed));

/*
* efi_dir is allocated in arch/ia64/kernel/efi.c.