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-rw-r--r--drivers/firmware/efi/Kconfig6
-rw-r--r--drivers/firmware/efi/Makefile1
-rw-r--r--drivers/firmware/efi/earlycon.c206
3 files changed, 213 insertions, 0 deletions
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig
index 89110dfc7127..190be0b1d109 100644
--- a/drivers/firmware/efi/Kconfig
+++ b/drivers/firmware/efi/Kconfig
@@ -198,3 +198,9 @@ config EFI_DEV_PATH_PARSER
bool
depends on ACPI
default n
+
+config EFI_EARLYCON
+ def_bool y
+ depends on SERIAL_EARLYCON && !ARM && !IA64
+ select FONT_SUPPORT
+ select ARCH_USE_MEMREMAP_PROT
diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile
index 5f9f5039de50..d2d0d2030620 100644
--- a/drivers/firmware/efi/Makefile
+++ b/drivers/firmware/efi/Makefile
@@ -30,5 +30,6 @@ arm-obj-$(CONFIG_EFI) := arm-init.o arm-runtime.o
obj-$(CONFIG_ARM) += $(arm-obj-y)
obj-$(CONFIG_ARM64) += $(arm-obj-y)
obj-$(CONFIG_EFI_CAPSULE_LOADER) += capsule-loader.o
+obj-$(CONFIG_EFI_EARLYCON) += earlycon.o
obj-$(CONFIG_UEFI_CPER_ARM) += cper-arm.o
obj-$(CONFIG_UEFI_CPER_X86) += cper-x86.o
diff --git a/drivers/firmware/efi/earlycon.c b/drivers/firmware/efi/earlycon.c
new file mode 100644
index 000000000000..c9a0efca17b0
--- /dev/null
+++ b/drivers/firmware/efi/earlycon.c
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2013 Intel Corporation; author Matt Fleming
+ */
+
+#include <linux/console.h>
+#include <linux/efi.h>
+#include <linux/font.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/serial_core.h>
+#include <linux/screen_info.h>
+
+#include <asm/early_ioremap.h>
+
+static const struct font_desc *font;
+static u32 efi_x, efi_y;
+static u64 fb_base;
+static pgprot_t fb_prot;
+
+static __ref void *efi_earlycon_map(unsigned long start, unsigned long len)
+{
+ return early_memremap_prot(fb_base + start, len, pgprot_val(fb_prot));
+}
+
+static __ref void efi_earlycon_unmap(void *addr, unsigned long len)
+{
+ early_memunmap(addr, len);
+}
+
+static void efi_earlycon_clear_scanline(unsigned int y)
+{
+ unsigned long *dst;
+ u16 len;
+
+ len = screen_info.lfb_linelength;
+ dst = efi_earlycon_map(y*len, len);
+ if (!dst)
+ return;
+
+ memset(dst, 0, len);
+ efi_earlycon_unmap(dst, len);
+}
+
+static void efi_earlycon_scroll_up(void)
+{
+ unsigned long *dst, *src;
+ u16 len;
+ u32 i, height;
+
+ len = screen_info.lfb_linelength;
+ height = screen_info.lfb_height;
+
+ for (i = 0; i < height - font->height; i++) {
+ dst = efi_earlycon_map(i*len, len);
+ if (!dst)
+ return;
+
+ src = efi_earlycon_map((i + font->height) * len, len);
+ if (!src) {
+ efi_earlycon_unmap(dst, len);
+ return;
+ }
+
+ memmove(dst, src, len);
+
+ efi_earlycon_unmap(src, len);
+ efi_earlycon_unmap(dst, len);
+ }
+}
+
+static void efi_earlycon_write_char(u32 *dst, unsigned char c, unsigned int h)
+{
+ const u32 color_black = 0x00000000;
+ const u32 color_white = 0x00ffffff;
+ const u8 *src;
+ u8 s8;
+ int m;
+
+ src = font->data + c * font->height;
+ s8 = *(src + h);
+
+ for (m = 0; m < 8; m++) {
+ if ((s8 >> (7 - m)) & 1)
+ *dst = color_white;
+ else
+ *dst = color_black;
+ dst++;
+ }
+}
+
+static void
+efi_earlycon_write(struct console *con, const char *str, unsigned int num)
+{
+ struct screen_info *si;
+ unsigned int len;
+ const char *s;
+ void *dst;
+
+ si = &screen_info;
+ len = si->lfb_linelength;
+
+ while (num) {
+ unsigned int linemax;
+ unsigned int h, count = 0;
+
+ for (s = str; *s && *s != '\n'; s++) {
+ if (count == num)
+ break;
+ count++;
+ }
+
+ linemax = (si->lfb_width - efi_x) / font->width;
+ if (count > linemax)
+ count = linemax;
+
+ for (h = 0; h < font->height; h++) {
+ unsigned int n, x;
+
+ dst = efi_earlycon_map((efi_y + h) * len, len);
+ if (!dst)
+ return;
+
+ s = str;
+ n = count;
+ x = efi_x;
+
+ while (n-- > 0) {
+ efi_earlycon_write_char(dst + x*4, *s, h);
+ x += font->width;
+ s++;
+ }
+
+ efi_earlycon_unmap(dst, len);
+ }
+
+ num -= count;
+ efi_x += count * font->width;
+ str += count;
+
+ if (num > 0 && *s == '\n') {
+ efi_x = 0;
+ efi_y += font->height;
+ str++;
+ num--;
+ }
+
+ if (efi_x + font->width > si->lfb_width) {
+ efi_x = 0;
+ efi_y += font->height;
+ }
+
+ if (efi_y + font->height > si->lfb_height) {
+ u32 i;
+
+ efi_y -= font->height;
+ efi_earlycon_scroll_up();
+
+ for (i = 0; i < font->height; i++)
+ efi_earlycon_clear_scanline(efi_y + i);
+ }
+ }
+}
+
+static int __init efi_earlycon_setup(struct earlycon_device *device,
+ const char *opt)
+{
+ struct screen_info *si;
+ u16 xres, yres;
+ u32 i;
+
+ if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
+ return -ENODEV;
+
+ fb_base = screen_info.lfb_base;
+ if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
+ fb_base |= (u64)screen_info.ext_lfb_base << 32;
+
+ if (opt && !strcmp(opt, "ram"))
+ fb_prot = PAGE_KERNEL;
+ else
+ fb_prot = pgprot_writecombine(PAGE_KERNEL);
+
+ si = &screen_info;
+ xres = si->lfb_width;
+ yres = si->lfb_height;
+
+ /*
+ * efi_earlycon_write_char() implicitly assumes a framebuffer with
+ * 32 bits per pixel.
+ */
+ if (si->lfb_depth != 32)
+ return -ENODEV;
+
+ font = get_default_font(xres, yres, -1, -1);
+ if (!font)
+ return -ENODEV;
+
+ efi_y = rounddown(yres, font->height) - font->height;
+ for (i = 0; i < (yres - efi_y) / font->height; i++)
+ efi_earlycon_scroll_up();
+
+ device->con->write = efi_earlycon_write;
+ return 0;
+}
+EARLYCON_DECLARE(efifb, efi_earlycon_setup);