linux/drivers/firmware/efi/earlycon.c
Dave Young 8f592ada59 efi/earlycon: Fix early printk for wider fonts
When I play with terminus fonts I noticed the efi early printk does
not work because the earlycon code assumes font width is 8.

Here add the code to adapt with larger fonts.  Tested with all kinds
of kernel built-in fonts on my laptop. Also tested with a local draft
patch for 14x28 !bold terminus font.

Signed-off-by: Dave Young <dyoung@redhat.com>
Link: https://lore.kernel.org/r/20200412024927.GA6884@dhcp-128-65.nay.redhat.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-05-12 12:29:45 +02:00

247 lines
5.2 KiB
C

// 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 console *earlycon_console __initdata;
static const struct font_desc *font;
static u32 efi_x, efi_y;
static u64 fb_base;
static bool fb_wb;
static void *efi_fb;
/*
* EFI earlycon needs to use early_memremap() to map the framebuffer.
* But early_memremap() is not usable for 'earlycon=efifb keep_bootcon',
* memremap() should be used instead. memremap() will be available after
* paging_init() which is earlier than initcall callbacks. Thus adding this
* early initcall function early_efi_map_fb() to map the whole EFI framebuffer.
*/
static int __init efi_earlycon_remap_fb(void)
{
/* bail if there is no bootconsole or it has been disabled already */
if (!earlycon_console || !(earlycon_console->flags & CON_ENABLED))
return 0;
efi_fb = memremap(fb_base, screen_info.lfb_size,
fb_wb ? MEMREMAP_WB : MEMREMAP_WC);
return efi_fb ? 0 : -ENOMEM;
}
early_initcall(efi_earlycon_remap_fb);
static int __init efi_earlycon_unmap_fb(void)
{
/* unmap the bootconsole fb unless keep_bootcon has left it enabled */
if (efi_fb && !(earlycon_console->flags & CON_ENABLED))
memunmap(efi_fb);
return 0;
}
late_initcall(efi_earlycon_unmap_fb);
static __ref void *efi_earlycon_map(unsigned long start, unsigned long len)
{
pgprot_t fb_prot;
if (efi_fb)
return efi_fb + start;
fb_prot = fb_wb ? PAGE_KERNEL : pgprot_writecombine(PAGE_KERNEL);
return early_memremap_prot(fb_base + start, len, pgprot_val(fb_prot));
}
static __ref void efi_earlycon_unmap(void *addr, unsigned long len)
{
if (efi_fb)
return;
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;
int m, n, bytes;
u8 x;
bytes = BITS_TO_BYTES(font->width);
src = font->data + c * font->height * bytes + h * bytes;
for (m = 0; m < font->width; m++) {
n = m % 8;
x = *(src + m / 8);
if ((x >> (7 - n)) & 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;
fb_wb = opt && !strcmp(opt, "ram");
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;
earlycon_console = device->con;
return 0;
}
EARLYCON_DECLARE(efifb, efi_earlycon_setup);