From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/x86/platform/efi/early_printk.c | 237 +++++++++++++++++++++++++++++++++++ 1 file changed, 237 insertions(+) create mode 100644 arch/x86/platform/efi/early_printk.c (limited to 'arch/x86/platform/efi/early_printk.c') diff --git a/arch/x86/platform/efi/early_printk.c b/arch/x86/platform/efi/early_printk.c new file mode 100644 index 000000000..5eb772c0d --- /dev/null +++ b/arch/x86/platform/efi/early_printk.c @@ -0,0 +1,237 @@ +/* + * Copyright (C) 2013 Intel Corporation; author Matt Fleming + * + * This file is part of the Linux kernel, and is made available under + * the terms of the GNU General Public License version 2. + */ + +#include +#include +#include +#include +#include +#include + +static const struct font_desc *font; +static u32 efi_x, efi_y; +static void *efi_fb; +static bool early_efi_keep; + +/* + * efi earlyprintk need use early_ioremap to map the framebuffer. + * But early_ioremap is not usable for earlyprintk=efi,keep, ioremap should + * be used instead. ioremap 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 __init int early_efi_map_fb(void) +{ + unsigned long base, size; + + if (!early_efi_keep) + return 0; + + base = boot_params.screen_info.lfb_base; + size = boot_params.screen_info.lfb_size; + efi_fb = ioremap(base, size); + + return efi_fb ? 0 : -ENOMEM; +} +early_initcall(early_efi_map_fb); + +/* + * early_efi_map maps efi framebuffer region [start, start + len -1] + * In case earlyprintk=efi,keep we have the whole framebuffer mapped already + * so just return the offset efi_fb + start. + */ +static __init_refok void *early_efi_map(unsigned long start, unsigned long len) +{ + unsigned long base; + + base = boot_params.screen_info.lfb_base; + + if (efi_fb) + return (efi_fb + start); + else + return early_ioremap(base + start, len); +} + +static __init_refok void early_efi_unmap(void *addr, unsigned long len) +{ + if (!efi_fb) + early_iounmap(addr, len); +} + +static void early_efi_clear_scanline(unsigned int y) +{ + unsigned long *dst; + u16 len; + + len = boot_params.screen_info.lfb_linelength; + dst = early_efi_map(y*len, len); + if (!dst) + return; + + memset(dst, 0, len); + early_efi_unmap(dst, len); +} + +static void early_efi_scroll_up(void) +{ + unsigned long *dst, *src; + u16 len; + u32 i, height; + + len = boot_params.screen_info.lfb_linelength; + height = boot_params.screen_info.lfb_height; + + for (i = 0; i < height - font->height; i++) { + dst = early_efi_map(i*len, len); + if (!dst) + return; + + src = early_efi_map((i + font->height) * len, len); + if (!src) { + early_efi_unmap(dst, len); + return; + } + + memmove(dst, src, len); + + early_efi_unmap(src, len); + early_efi_unmap(dst, len); + } +} + +static void early_efi_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 +early_efi_write(struct console *con, const char *str, unsigned int num, + unsigned int loglevel) +{ + struct screen_info *si; + unsigned int len; + const char *s; + void *dst; + + si = &boot_params.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 = early_efi_map((efi_y + h) * len, len); + if (!dst) + return; + + s = str; + n = count; + x = efi_x; + + while (n-- > 0) { + early_efi_write_char(dst + x*4, *s, h); + x += font->width; + s++; + } + + early_efi_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 >= si->lfb_width) { + efi_x = 0; + efi_y += font->height; + } + + if (efi_y + font->height > si->lfb_height) { + u32 i; + + efi_y -= font->height; + early_efi_scroll_up(); + + for (i = 0; i < font->height; i++) + early_efi_clear_scanline(efi_y + i); + } + } +} + +static __init int early_efi_setup(struct console *con, char *options) +{ + struct screen_info *si; + u16 xres, yres; + u32 i; + + si = &boot_params.screen_info; + xres = si->lfb_width; + yres = si->lfb_height; + + /* + * early_efi_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++) + early_efi_scroll_up(); + + /* early_console_register will unset CON_BOOT in case ,keep */ + if (!(con->flags & CON_BOOT)) + early_efi_keep = true; + return 0; +} + +struct console early_efi_console = { + .name = "earlyefi", + .write = early_efi_write, + .setup = early_efi_setup, + .flags = CON_PRINTBUFFER, + .index = -1, +}; -- cgit v1.2.3-54-g00ecf