From b41b6e23694394776e9b7e55632adef9eb075296 Mon Sep 17 00:00:00 2001 From: xamidev Date: Sun, 21 Dec 2025 14:56:19 +0100 Subject: [PATCH 1/3] Hello, world! in linear framebuffer --- Makefile | 6 ++- README.md | 7 ++++ src/kernel.h | 9 +++++ src/kmain.c | 13 ++++--- src/term.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++ src/term.h | 22 +++++++++++ zap-light16.psf | Bin 0 -> 5312 bytes 7 files changed, 149 insertions(+), 7 deletions(-) create mode 100644 src/kernel.h create mode 100644 src/term.c create mode 100644 src/term.h create mode 100644 zap-light16.psf diff --git a/Makefile b/Makefile index 92c59c1..56616ed 100644 --- a/Makefile +++ b/Makefile @@ -1,6 +1,7 @@ build: rm -f *.o - x86_64-elf-gcc -c -I src src/kmain.c -Wall -Wextra -std=gnu99 -nostdlib -ffreestanding -fno-stack-protector -fno-stack-check -fno-PIC -ffunction-sections -fdata-sections + x86_64-elf-gcc -c -I src src/term.c src/kmain.c -Wall -Wextra -std=gnu99 -nostdlib -ffreestanding -fno-stack-protector -fno-stack-check -fno-PIC -ffunction-sections -fdata-sections -mcmodel=kernel + objcopy -O elf64-x86-64 -B i386 -I binary zap-light16.psf zap-light16.o x86_64-elf-ld -o kernel -T linker.ld *.o limine/limine: @@ -25,5 +26,8 @@ build-iso: limine/limine build iso_root -o kernel.iso ./limine/limine bios-install kernel.iso +run: + qemu-system-x86_64 -cdrom kernel.iso + clean: rm -rf *.o kernel iso_root kernel.iso limine diff --git a/README.md b/README.md index dacc5de..518f056 100644 --- a/README.md +++ b/README.md @@ -9,3 +9,10 @@ make build-iso ``` Then it can be run with `qemu-system-x86_64 kernel.iso`. + + +### Kernel conventions + +Functions that return an integer as status of success/failure will return: +- 0 if everything went correctly +- a negative value if something went wrong diff --git a/src/kernel.h b/src/kernel.h new file mode 100644 index 0000000..918fa6a --- /dev/null +++ b/src/kernel.h @@ -0,0 +1,9 @@ +#ifndef KERNEL_H +#define KERNEL_H + +enum ErrorCodes +{ + ENOMEM +}; + +#endif diff --git a/src/kmain.c b/src/kmain.c index 2f35998..3c321eb 100644 --- a/src/kmain.c +++ b/src/kmain.c @@ -1,6 +1,7 @@ #include #include #include +#include "term.h" // Limine version used __attribute__((used, section(".limine_requests"))) @@ -19,6 +20,8 @@ static volatile LIMINE_REQUESTS_START_MARKER; __attribute__((used, section(".limine_requests_end"))) static volatile LIMINE_REQUESTS_END_MARKER; +struct limine_framebuffer* framebuffer; + // We won't be linked to standard library, but still need the basic mem* functions // so everything goes allright with the compiler @@ -103,14 +106,12 @@ void kmain() if (framebuffer_request.response == NULL || framebuffer_request.response->framebuffer_count < 1) hcf(); // Get the first framebuffer from the response - struct limine_framebuffer* framebuffer = framebuffer_request.response->framebuffers[0]; + framebuffer = framebuffer_request.response->framebuffers[0]; + + if (term_init()) hcf(); // Draw something - for (size_t i=0; i<100; i++) - { - volatile uint32_t* fb_ptr = framebuffer->address; - fb_ptr[i*(framebuffer->pitch/4) + i] = 0xffffff; - } + kputs("Hello, world!"); hcf(); } diff --git a/src/term.c b/src/term.c new file mode 100644 index 0000000..dd1e397 --- /dev/null +++ b/src/term.c @@ -0,0 +1,99 @@ +// Terminal output + +#include +#include +#include "kernel.h" +#include "term.h" + +extern struct limine_framebuffer* framebuffer; + +// Importing the PSF object file +extern unsigned char _binary_zap_light16_psf_start[]; +extern unsigned char _binary_zap_light16_psf_end[]; + +PSF1_Header* font = (PSF1_Header*)_binary_zap_light16_psf_start; +uint8_t* glyphs = _binary_zap_light16_psf_start + sizeof(PSF1_Header); + +#define FONT_WIDTH 8 +#define FONT_HEIGHT font->characterSize + +// Character cursor +typedef struct +{ + unsigned int x; + unsigned int y; +} Cursor; + +Cursor cursor = {0}; + +unsigned char* fb; + +int term_init() +{ + // Get framebuffer address from Limine struct + + if (framebuffer) + { + fb = framebuffer->address; + return 0; + } + return -ENOMEM; +} + +// These are marked "static" because we don't wanna expose them all around +// AKA they should just be seen here (kind of like private functions in cpp) +static void putpixel(int x, int y, int color) +{ + // Depth isn't part of limine_framebuffer attributes so it will be 4 + unsigned pos = x*4 + y*framebuffer->pitch; + fb[pos] = color & 255; // blue channel + fb[pos+1] = (color >> 8) & 255; // green + fb[pos+2] = (color >> 16) & 255; // blue +} + +static void draw_char(char c, int px, int py, int fg, int bg) +{ + uint8_t* glyph = glyphs + ((unsigned char)c * FONT_HEIGHT); + + for (size_t y=0; y> x)) ? fg : bg; + putpixel(px+x, py+y, color); + } + } +} + +static void putchar(char c) +{ + if (c == '\n') + { + cursor.x = 0; + cursor.y++; + return; + } + + if ((cursor.x+1)*FONT_WIDTH >= framebuffer->width) + { + cursor.x = 0; + cursor.y++; + } + + int px = cursor.x * FONT_WIDTH; + int py = cursor.y * FONT_HEIGHT; + draw_char(c, px, py, WHITE, BLACK); + cursor.x++; +} + +// Debug-printing +void kputs(const char* str) +{ + unsigned int i=0; + while (str[i] != 0) + { + putchar(str[i]); + i++; + } +} \ No newline at end of file diff --git a/src/term.h b/src/term.h new file mode 100644 index 0000000..c7bcf5c --- /dev/null +++ b/src/term.h @@ -0,0 +1,22 @@ +#ifndef TERM_H +#define TERM_H + +int term_init(); +void kputs(const char* str); + +enum TermColors +{ + BLACK = 0x000000, + WHITE = 0xffffff +}; + +#define PSF1_FONT_MAGIC 0x0436 + +typedef struct +{ + uint16_t magic; + uint8_t fontMode; + uint8_t characterSize; // height +} PSF1_Header; + +#endif diff --git a/zap-light16.psf b/zap-light16.psf new file mode 100644 index 0000000000000000000000000000000000000000..047bd1b0be57f5165922969887fd5c6b3ede3304 GIT binary patch literal 5312 zcmZvfYj|8m8ONumYuWPTX}2NR#ja$!-P22gWqTn_!x}b+CGLjWrV9ZrErg^*Q7#pg zR#-M)dH5vt6W^#dDpo?=ZroX2GPqlk>dUR5~-O%TA{=x~wy4)o?nKPI)+}R{f?) z&a6~suyM9AC~c84#mtiKRJwcR*kaFX>CDQSms*V8lP)g2tIeL4q?CK8LP3I@JEhY_ zrOv~1*m$S+7`IpwMUvC_SREWZSj}YmCMF)R`sEuYw%fO4UaQ5L8DRXa#0)TglbE^g zmO;_qLbYAD-a9RwH8UC72ui9H1m*J9AmEiG`Oqk8bjb695`%DqWmr+{tR247Qoq>c zQQyoDP9<9q>!_Z6+RAC>Ni@Ccm~jf&AhJh{Kke44)!~H;Yi>r@jg4(gr(eHj&8Ur+ z#WTD5s$g`pXrjBBvR0L%z@&6KB}JNHo0Q3D=aR1V<@#!^3CBDO&Kf-^X+>^ErLAXF z!Shn4O|7ks`3c7A(frcG>}o=hTJtB{TbEr-{Jk7=Z`VVqR98=-Qfa1Aru#}Y%jI&z zlf|*|a~e(fNH?PnxZXekizj(MF#JX(l zrhdGi+0i7^oNKRhKld`Tq)NrjM^LGbPfm_kE6!h zY;1JY`P05lZhh?7BtqOjvG15E%{K*NZ&WLcGPb+(WVLKXo2<6M$z6OplF#RRdZP71 z*J=|J)6-G^0?vn-bX#BCaVA+U`$e{&o6np*Et2PqgEl87mGV3z2W?*@mkCSvb;Qr5l~yHw)5cNLR5TS)5lTaua| zfkb^oLeom`>T0!FC2g}!vO8olnSaJX`|qn)VZ#_7a-0d$y7d0PRX8S=tT05BJG{L3d@Z8+tN9Jri znZ!hr9h)d%=;rG}Zb#B!C6(3XR{Q8da}gOUbvy27itUQb?66nH@I9oV^GT+L$)da6 zjz4j}GsSVaQDWc0iv04mv=|tD>#K4TYqM1rXj4>YpjO+)dddC5e(&55+{1iYmD}z= z{6bf^{Wg*JDCA;ii1g_WNBMG>6cwMgGS*T3*xnH@j12DC*`LUMe?Iva`MKugagHKu zJ%=GG3Zq&*9m&P*%`CMBr_ZELCLEV$dacEko=lxd=%rEp*zW4Pc%eF#hAbgoaP&Bd~d(3fjzmC>_0{`JKzojRLxW-c5~Tua z+kL>4q;oR9_U{GPKRMFI?)n#N*S}axeRtyo4nH zgg)-itn~X=^@rh66^6&)%kWY7ID85A&kIAX!*DqiA-_BfSMuBpLy*(GdVuE}^%3ty z?o?-xU`HVjABKIfr`&y-Z*XuA`P1zdgQ(N^?#?;UICF+Ft25fIqpX7ur(cSt2 zeWmWkx>gk^zf@K9g{UIF>tH=>fQ@h&48SHBgv~Id2JpU|w-UTrl^NYIZ&yGWMj(JI zp#oRID7*!#P=hhJTJDgphil+kn1JixdUzYW9d^JCuv5LdCJcA+ zcB6XIJMPV2!Hl9N)f3(^?^!Ram+8xN7~V|T6imZzxCLh59q>-L72XB!hTGtFxC8El zJ@6j53*HOwgZIPTuow2h2jCvK7aD2>GjtzsP4$Au%IS;pCwz7wC0~QD!#ChbcuMs% z3&(l;CVUH?hG*be_%?h8o`VzcU6o4#7cq3?5fcGn!AS=gB{f{tSE;?xW7< z)ltsZ7f@eRtMpU(b?k~J<%cOb0#864eGTk`ub`FRqc7Btvtk~->hfn|q1-oJo+hrg73m%ogB(qBP7 z?e~+<_#4P?^)DyC&A*!bet2+s7=8#o2>anz^z_&88~82!4t@`RfIq^Y;Lq?E_$&Mk m{thp}Kj5G6GQ0x+f|Kwn{2NZeY4{KP7ybul;59f4A^aazON1E! literal 0 HcmV?d00001 -- 2.49.1 From ef5f658a623f221e4ea5ce4a15b72a29a429148c Mon Sep 17 00:00:00 2001 From: xamidev Date: Sun, 21 Dec 2025 15:34:45 +0100 Subject: [PATCH 2/3] Portable printf added --- Makefile | 4 +- README.md | 7 + src/io/printf.c | 914 ++++++++++++++++++++++++++++++++++++++++++++ src/io/printf.h | 117 ++++++ src/{ => io}/term.c | 6 + src/{ => io}/term.h | 0 src/kmain.c | 5 +- 7 files changed, 1049 insertions(+), 4 deletions(-) create mode 100644 src/io/printf.c create mode 100644 src/io/printf.h rename src/{ => io}/term.c (95%) rename src/{ => io}/term.h (100%) diff --git a/Makefile b/Makefile index 56616ed..3a995ce 100644 --- a/Makefile +++ b/Makefile @@ -1,6 +1,6 @@ build: rm -f *.o - x86_64-elf-gcc -c -I src src/term.c src/kmain.c -Wall -Wextra -std=gnu99 -nostdlib -ffreestanding -fno-stack-protector -fno-stack-check -fno-PIC -ffunction-sections -fdata-sections -mcmodel=kernel + x86_64-elf-gcc -c -I src src/io/term.c src/io/printf.c src/kmain.c -Wall -Wextra -std=gnu99 -nostdlib -ffreestanding -fno-stack-protector -fno-stack-check -fno-PIC -ffunction-sections -fdata-sections -mcmodel=kernel objcopy -O elf64-x86-64 -B i386 -I binary zap-light16.psf zap-light16.o x86_64-elf-ld -o kernel -T linker.ld *.o @@ -26,7 +26,7 @@ build-iso: limine/limine build iso_root -o kernel.iso ./limine/limine bios-install kernel.iso -run: +run: build-iso qemu-system-x86_64 -cdrom kernel.iso clean: diff --git a/README.md b/README.md index 518f056..18a5428 100644 --- a/README.md +++ b/README.md @@ -16,3 +16,10 @@ Then it can be run with `qemu-system-x86_64 kernel.iso`. Functions that return an integer as status of success/failure will return: - 0 if everything went correctly - a negative value if something went wrong + +### Thanks + +PepperOS wouldn't be possible without: + +- the [Limine](https://codeberg.org/Limine/Limine) portable bootloader +- Marco Paland's freestanding [printf implementation](https://github.com/mpaland) diff --git a/src/io/printf.c b/src/io/printf.c new file mode 100644 index 0000000..d34279a --- /dev/null +++ b/src/io/printf.c @@ -0,0 +1,914 @@ +/////////////////////////////////////////////////////////////////////////////// +// \author (c) Marco Paland (info@paland.com) +// 2014-2019, PALANDesign Hannover, Germany +// +// \license The MIT License (MIT) +// +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to deal +// in the Software without restriction, including without limitation the rights +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the Software is +// furnished to do so, subject to the following conditions: +// +// The above copyright notice and this permission notice shall be included in +// all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. +// +// \brief Tiny printf, sprintf and (v)snprintf implementation, optimized for speed on +// embedded systems with a very limited resources. These routines are thread +// safe and reentrant! +// Use this instead of the bloated standard/newlib printf cause these use +// malloc for printf (and may not be thread safe). +// +/////////////////////////////////////////////////////////////////////////////// + +#include +#include + +#include "printf.h" + + +// define this globally (e.g. gcc -DPRINTF_INCLUDE_CONFIG_H ...) to include the +// printf_config.h header file +// default: undefined +#ifdef PRINTF_INCLUDE_CONFIG_H +#include "printf_config.h" +#endif + + +// 'ntoa' conversion buffer size, this must be big enough to hold one converted +// numeric number including padded zeros (dynamically created on stack) +// default: 32 byte +#ifndef PRINTF_NTOA_BUFFER_SIZE +#define PRINTF_NTOA_BUFFER_SIZE 32U +#endif + +// 'ftoa' conversion buffer size, this must be big enough to hold one converted +// float number including padded zeros (dynamically created on stack) +// default: 32 byte +#ifndef PRINTF_FTOA_BUFFER_SIZE +#define PRINTF_FTOA_BUFFER_SIZE 32U +#endif + +// support for the floating point type (%f) +// default: activated +#ifndef PRINTF_DISABLE_SUPPORT_FLOAT +#define PRINTF_SUPPORT_FLOAT +#endif + +// support for exponential floating point notation (%e/%g) +// default: activated +#ifndef PRINTF_DISABLE_SUPPORT_EXPONENTIAL +#define PRINTF_SUPPORT_EXPONENTIAL +#endif + +// define the default floating point precision +// default: 6 digits +#ifndef PRINTF_DEFAULT_FLOAT_PRECISION +#define PRINTF_DEFAULT_FLOAT_PRECISION 6U +#endif + +// define the largest float suitable to print with %f +// default: 1e9 +#ifndef PRINTF_MAX_FLOAT +#define PRINTF_MAX_FLOAT 1e9 +#endif + +// support for the long long types (%llu or %p) +// default: activated +#ifndef PRINTF_DISABLE_SUPPORT_LONG_LONG +#define PRINTF_SUPPORT_LONG_LONG +#endif + +// support for the ptrdiff_t type (%t) +// ptrdiff_t is normally defined in as long or long long type +// default: activated +#ifndef PRINTF_DISABLE_SUPPORT_PTRDIFF_T +#define PRINTF_SUPPORT_PTRDIFF_T +#endif + +/////////////////////////////////////////////////////////////////////////////// + +// internal flag definitions +#define FLAGS_ZEROPAD (1U << 0U) +#define FLAGS_LEFT (1U << 1U) +#define FLAGS_PLUS (1U << 2U) +#define FLAGS_SPACE (1U << 3U) +#define FLAGS_HASH (1U << 4U) +#define FLAGS_UPPERCASE (1U << 5U) +#define FLAGS_CHAR (1U << 6U) +#define FLAGS_SHORT (1U << 7U) +#define FLAGS_LONG (1U << 8U) +#define FLAGS_LONG_LONG (1U << 9U) +#define FLAGS_PRECISION (1U << 10U) +#define FLAGS_ADAPT_EXP (1U << 11U) + + +// import float.h for DBL_MAX +#if defined(PRINTF_SUPPORT_FLOAT) +#include +#endif + + +// output function type +typedef void (*out_fct_type)(char character, void* buffer, size_t idx, size_t maxlen); + + +// wrapper (used as buffer) for output function type +typedef struct { + void (*fct)(char character, void* arg); + void* arg; +} out_fct_wrap_type; + + +// internal buffer output +static inline void _out_buffer(char character, void* buffer, size_t idx, size_t maxlen) +{ + if (idx < maxlen) { + ((char*)buffer)[idx] = character; + } +} + + +// internal null output +static inline void _out_null(char character, void* buffer, size_t idx, size_t maxlen) +{ + (void)character; (void)buffer; (void)idx; (void)maxlen; +} + + +// internal _putchar wrapper +static inline void _out_char(char character, void* buffer, size_t idx, size_t maxlen) +{ + (void)buffer; (void)idx; (void)maxlen; + if (character) { + _putchar(character); + } +} + + +// internal output function wrapper +static inline void _out_fct(char character, void* buffer, size_t idx, size_t maxlen) +{ + (void)idx; (void)maxlen; + if (character) { + // buffer is the output fct pointer + ((out_fct_wrap_type*)buffer)->fct(character, ((out_fct_wrap_type*)buffer)->arg); + } +} + + +// internal secure strlen +// \return The length of the string (excluding the terminating 0) limited by 'maxsize' +static inline unsigned int _strnlen_s(const char* str, size_t maxsize) +{ + const char* s; + for (s = str; *s && maxsize--; ++s); + return (unsigned int)(s - str); +} + + +// internal test if char is a digit (0-9) +// \return true if char is a digit +static inline bool _is_digit(char ch) +{ + return (ch >= '0') && (ch <= '9'); +} + + +// internal ASCII string to unsigned int conversion +static unsigned int _atoi(const char** str) +{ + unsigned int i = 0U; + while (_is_digit(**str)) { + i = i * 10U + (unsigned int)(*((*str)++) - '0'); + } + return i; +} + + +// output the specified string in reverse, taking care of any zero-padding +static size_t _out_rev(out_fct_type out, char* buffer, size_t idx, size_t maxlen, const char* buf, size_t len, unsigned int width, unsigned int flags) +{ + const size_t start_idx = idx; + + // pad spaces up to given width + if (!(flags & FLAGS_LEFT) && !(flags & FLAGS_ZEROPAD)) { + for (size_t i = len; i < width; i++) { + out(' ', buffer, idx++, maxlen); + } + } + + // reverse string + while (len) { + out(buf[--len], buffer, idx++, maxlen); + } + + // append pad spaces up to given width + if (flags & FLAGS_LEFT) { + while (idx - start_idx < width) { + out(' ', buffer, idx++, maxlen); + } + } + + return idx; +} + + +// internal itoa format +static size_t _ntoa_format(out_fct_type out, char* buffer, size_t idx, size_t maxlen, char* buf, size_t len, bool negative, unsigned int base, unsigned int prec, unsigned int width, unsigned int flags) +{ + // pad leading zeros + if (!(flags & FLAGS_LEFT)) { + if (width && (flags & FLAGS_ZEROPAD) && (negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) { + width--; + } + while ((len < prec) && (len < PRINTF_NTOA_BUFFER_SIZE)) { + buf[len++] = '0'; + } + while ((flags & FLAGS_ZEROPAD) && (len < width) && (len < PRINTF_NTOA_BUFFER_SIZE)) { + buf[len++] = '0'; + } + } + + // handle hash + if (flags & FLAGS_HASH) { + if (!(flags & FLAGS_PRECISION) && len && ((len == prec) || (len == width))) { + len--; + if (len && (base == 16U)) { + len--; + } + } + if ((base == 16U) && !(flags & FLAGS_UPPERCASE) && (len < PRINTF_NTOA_BUFFER_SIZE)) { + buf[len++] = 'x'; + } + else if ((base == 16U) && (flags & FLAGS_UPPERCASE) && (len < PRINTF_NTOA_BUFFER_SIZE)) { + buf[len++] = 'X'; + } + else if ((base == 2U) && (len < PRINTF_NTOA_BUFFER_SIZE)) { + buf[len++] = 'b'; + } + if (len < PRINTF_NTOA_BUFFER_SIZE) { + buf[len++] = '0'; + } + } + + if (len < PRINTF_NTOA_BUFFER_SIZE) { + if (negative) { + buf[len++] = '-'; + } + else if (flags & FLAGS_PLUS) { + buf[len++] = '+'; // ignore the space if the '+' exists + } + else if (flags & FLAGS_SPACE) { + buf[len++] = ' '; + } + } + + return _out_rev(out, buffer, idx, maxlen, buf, len, width, flags); +} + + +// internal itoa for 'long' type +static size_t _ntoa_long(out_fct_type out, char* buffer, size_t idx, size_t maxlen, unsigned long value, bool negative, unsigned long base, unsigned int prec, unsigned int width, unsigned int flags) +{ + char buf[PRINTF_NTOA_BUFFER_SIZE]; + size_t len = 0U; + + // no hash for 0 values + if (!value) { + flags &= ~FLAGS_HASH; + } + + // write if precision != 0 and value is != 0 + if (!(flags & FLAGS_PRECISION) || value) { + do { + const char digit = (char)(value % base); + buf[len++] = digit < 10 ? '0' + digit : (flags & FLAGS_UPPERCASE ? 'A' : 'a') + digit - 10; + value /= base; + } while (value && (len < PRINTF_NTOA_BUFFER_SIZE)); + } + + return _ntoa_format(out, buffer, idx, maxlen, buf, len, negative, (unsigned int)base, prec, width, flags); +} + + +// internal itoa for 'long long' type +#if defined(PRINTF_SUPPORT_LONG_LONG) +static size_t _ntoa_long_long(out_fct_type out, char* buffer, size_t idx, size_t maxlen, unsigned long long value, bool negative, unsigned long long base, unsigned int prec, unsigned int width, unsigned int flags) +{ + char buf[PRINTF_NTOA_BUFFER_SIZE]; + size_t len = 0U; + + // no hash for 0 values + if (!value) { + flags &= ~FLAGS_HASH; + } + + // write if precision != 0 and value is != 0 + if (!(flags & FLAGS_PRECISION) || value) { + do { + const char digit = (char)(value % base); + buf[len++] = digit < 10 ? '0' + digit : (flags & FLAGS_UPPERCASE ? 'A' : 'a') + digit - 10; + value /= base; + } while (value && (len < PRINTF_NTOA_BUFFER_SIZE)); + } + + return _ntoa_format(out, buffer, idx, maxlen, buf, len, negative, (unsigned int)base, prec, width, flags); +} +#endif // PRINTF_SUPPORT_LONG_LONG + + +#if defined(PRINTF_SUPPORT_FLOAT) + +#if defined(PRINTF_SUPPORT_EXPONENTIAL) +// forward declaration so that _ftoa can switch to exp notation for values > PRINTF_MAX_FLOAT +static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags); +#endif + + +// internal ftoa for fixed decimal floating point +static size_t _ftoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags) +{ + char buf[PRINTF_FTOA_BUFFER_SIZE]; + size_t len = 0U; + double diff = 0.0; + + // powers of 10 + static const double pow10[] = { 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000 }; + + // test for special values + if (value != value) + return _out_rev(out, buffer, idx, maxlen, "nan", 3, width, flags); + if (value < -DBL_MAX) + return _out_rev(out, buffer, idx, maxlen, "fni-", 4, width, flags); + if (value > DBL_MAX) + return _out_rev(out, buffer, idx, maxlen, (flags & FLAGS_PLUS) ? "fni+" : "fni", (flags & FLAGS_PLUS) ? 4U : 3U, width, flags); + + // test for very large values + // standard printf behavior is to print EVERY whole number digit -- which could be 100s of characters overflowing your buffers == bad + if ((value > PRINTF_MAX_FLOAT) || (value < -PRINTF_MAX_FLOAT)) { +#if defined(PRINTF_SUPPORT_EXPONENTIAL) + return _etoa(out, buffer, idx, maxlen, value, prec, width, flags); +#else + return 0U; +#endif + } + + // test for negative + bool negative = false; + if (value < 0) { + negative = true; + value = 0 - value; + } + + // set default precision, if not set explicitly + if (!(flags & FLAGS_PRECISION)) { + prec = PRINTF_DEFAULT_FLOAT_PRECISION; + } + // limit precision to 9, cause a prec >= 10 can lead to overflow errors + while ((len < PRINTF_FTOA_BUFFER_SIZE) && (prec > 9U)) { + buf[len++] = '0'; + prec--; + } + + int whole = (int)value; + double tmp = (value - whole) * pow10[prec]; + unsigned long frac = (unsigned long)tmp; + diff = tmp - frac; + + if (diff > 0.5) { + ++frac; + // handle rollover, e.g. case 0.99 with prec 1 is 1.0 + if (frac >= pow10[prec]) { + frac = 0; + ++whole; + } + } + else if (diff < 0.5) { + } + else if ((frac == 0U) || (frac & 1U)) { + // if halfway, round up if odd OR if last digit is 0 + ++frac; + } + + if (prec == 0U) { + diff = value - (double)whole; + if ((!(diff < 0.5) || (diff > 0.5)) && (whole & 1)) { + // exactly 0.5 and ODD, then round up + // 1.5 -> 2, but 2.5 -> 2 + ++whole; + } + } + else { + unsigned int count = prec; + // now do fractional part, as an unsigned number + while (len < PRINTF_FTOA_BUFFER_SIZE) { + --count; + buf[len++] = (char)(48U + (frac % 10U)); + if (!(frac /= 10U)) { + break; + } + } + // add extra 0s + while ((len < PRINTF_FTOA_BUFFER_SIZE) && (count-- > 0U)) { + buf[len++] = '0'; + } + if (len < PRINTF_FTOA_BUFFER_SIZE) { + // add decimal + buf[len++] = '.'; + } + } + + // do whole part, number is reversed + while (len < PRINTF_FTOA_BUFFER_SIZE) { + buf[len++] = (char)(48 + (whole % 10)); + if (!(whole /= 10)) { + break; + } + } + + // pad leading zeros + if (!(flags & FLAGS_LEFT) && (flags & FLAGS_ZEROPAD)) { + if (width && (negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) { + width--; + } + while ((len < width) && (len < PRINTF_FTOA_BUFFER_SIZE)) { + buf[len++] = '0'; + } + } + + if (len < PRINTF_FTOA_BUFFER_SIZE) { + if (negative) { + buf[len++] = '-'; + } + else if (flags & FLAGS_PLUS) { + buf[len++] = '+'; // ignore the space if the '+' exists + } + else if (flags & FLAGS_SPACE) { + buf[len++] = ' '; + } + } + + return _out_rev(out, buffer, idx, maxlen, buf, len, width, flags); +} + + +#if defined(PRINTF_SUPPORT_EXPONENTIAL) +// internal ftoa variant for exponential floating-point type, contributed by Martijn Jasperse +static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags) +{ + // check for NaN and special values + if ((value != value) || (value > DBL_MAX) || (value < -DBL_MAX)) { + return _ftoa(out, buffer, idx, maxlen, value, prec, width, flags); + } + + // determine the sign + const bool negative = value < 0; + if (negative) { + value = -value; + } + + // default precision + if (!(flags & FLAGS_PRECISION)) { + prec = PRINTF_DEFAULT_FLOAT_PRECISION; + } + + // determine the decimal exponent + // based on the algorithm by David Gay (https://www.ampl.com/netlib/fp/dtoa.c) + union { + uint64_t U; + double F; + } conv; + + conv.F = value; + int exp2 = (int)((conv.U >> 52U) & 0x07FFU) - 1023; // effectively log2 + conv.U = (conv.U & ((1ULL << 52U) - 1U)) | (1023ULL << 52U); // drop the exponent so conv.F is now in [1,2) + // now approximate log10 from the log2 integer part and an expansion of ln around 1.5 + int expval = (int)(0.1760912590558 + exp2 * 0.301029995663981 + (conv.F - 1.5) * 0.289529654602168); + // now we want to compute 10^expval but we want to be sure it won't overflow + exp2 = (int)(expval * 3.321928094887362 + 0.5); + const double z = expval * 2.302585092994046 - exp2 * 0.6931471805599453; + const double z2 = z * z; + conv.U = (uint64_t)(exp2 + 1023) << 52U; + // compute exp(z) using continued fractions, see https://en.wikipedia.org/wiki/Exponential_function#Continued_fractions_for_ex + conv.F *= 1 + 2 * z / (2 - z + (z2 / (6 + (z2 / (10 + z2 / 14))))); + // correct for rounding errors + if (value < conv.F) { + expval--; + conv.F /= 10; + } + + // the exponent format is "%+03d" and largest value is "307", so set aside 4-5 characters + unsigned int minwidth = ((expval < 100) && (expval > -100)) ? 4U : 5U; + + // in "%g" mode, "prec" is the number of *significant figures* not decimals + if (flags & FLAGS_ADAPT_EXP) { + // do we want to fall-back to "%f" mode? + if ((value >= 1e-4) && (value < 1e6)) { + if ((int)prec > expval) { + prec = (unsigned)((int)prec - expval - 1); + } + else { + prec = 0; + } + flags |= FLAGS_PRECISION; // make sure _ftoa respects precision + // no characters in exponent + minwidth = 0U; + expval = 0; + } + else { + // we use one sigfig for the whole part + if ((prec > 0) && (flags & FLAGS_PRECISION)) { + --prec; + } + } + } + + // will everything fit? + unsigned int fwidth = width; + if (width > minwidth) { + // we didn't fall-back so subtract the characters required for the exponent + fwidth -= minwidth; + } else { + // not enough characters, so go back to default sizing + fwidth = 0U; + } + if ((flags & FLAGS_LEFT) && minwidth) { + // if we're padding on the right, DON'T pad the floating part + fwidth = 0U; + } + + // rescale the float value + if (expval) { + value /= conv.F; + } + + // output the floating part + const size_t start_idx = idx; + idx = _ftoa(out, buffer, idx, maxlen, negative ? -value : value, prec, fwidth, flags & ~FLAGS_ADAPT_EXP); + + // output the exponent part + if (minwidth) { + // output the exponential symbol + out((flags & FLAGS_UPPERCASE) ? 'E' : 'e', buffer, idx++, maxlen); + // output the exponent value + idx = _ntoa_long(out, buffer, idx, maxlen, (expval < 0) ? -expval : expval, expval < 0, 10, 0, minwidth-1, FLAGS_ZEROPAD | FLAGS_PLUS); + // might need to right-pad spaces + if (flags & FLAGS_LEFT) { + while (idx - start_idx < width) out(' ', buffer, idx++, maxlen); + } + } + return idx; +} +#endif // PRINTF_SUPPORT_EXPONENTIAL +#endif // PRINTF_SUPPORT_FLOAT + + +// internal vsnprintf +static int _vsnprintf(out_fct_type out, char* buffer, const size_t maxlen, const char* format, va_list va) +{ + unsigned int flags, width, precision, n; + size_t idx = 0U; + + if (!buffer) { + // use null output function + out = _out_null; + } + + while (*format) + { + // format specifier? %[flags][width][.precision][length] + if (*format != '%') { + // no + out(*format, buffer, idx++, maxlen); + format++; + continue; + } + else { + // yes, evaluate it + format++; + } + + // evaluate flags + flags = 0U; + do { + switch (*format) { + case '0': flags |= FLAGS_ZEROPAD; format++; n = 1U; break; + case '-': flags |= FLAGS_LEFT; format++; n = 1U; break; + case '+': flags |= FLAGS_PLUS; format++; n = 1U; break; + case ' ': flags |= FLAGS_SPACE; format++; n = 1U; break; + case '#': flags |= FLAGS_HASH; format++; n = 1U; break; + default : n = 0U; break; + } + } while (n); + + // evaluate width field + width = 0U; + if (_is_digit(*format)) { + width = _atoi(&format); + } + else if (*format == '*') { + const int w = va_arg(va, int); + if (w < 0) { + flags |= FLAGS_LEFT; // reverse padding + width = (unsigned int)-w; + } + else { + width = (unsigned int)w; + } + format++; + } + + // evaluate precision field + precision = 0U; + if (*format == '.') { + flags |= FLAGS_PRECISION; + format++; + if (_is_digit(*format)) { + precision = _atoi(&format); + } + else if (*format == '*') { + const int prec = (int)va_arg(va, int); + precision = prec > 0 ? (unsigned int)prec : 0U; + format++; + } + } + + // evaluate length field + switch (*format) { + case 'l' : + flags |= FLAGS_LONG; + format++; + if (*format == 'l') { + flags |= FLAGS_LONG_LONG; + format++; + } + break; + case 'h' : + flags |= FLAGS_SHORT; + format++; + if (*format == 'h') { + flags |= FLAGS_CHAR; + format++; + } + break; +#if defined(PRINTF_SUPPORT_PTRDIFF_T) + case 't' : + flags |= (sizeof(ptrdiff_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG); + format++; + break; +#endif + case 'j' : + flags |= (sizeof(intmax_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG); + format++; + break; + case 'z' : + flags |= (sizeof(size_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG); + format++; + break; + default : + break; + } + + // evaluate specifier + switch (*format) { + case 'd' : + case 'i' : + case 'u' : + case 'x' : + case 'X' : + case 'o' : + case 'b' : { + // set the base + unsigned int base; + if (*format == 'x' || *format == 'X') { + base = 16U; + } + else if (*format == 'o') { + base = 8U; + } + else if (*format == 'b') { + base = 2U; + } + else { + base = 10U; + flags &= ~FLAGS_HASH; // no hash for dec format + } + // uppercase + if (*format == 'X') { + flags |= FLAGS_UPPERCASE; + } + + // no plus or space flag for u, x, X, o, b + if ((*format != 'i') && (*format != 'd')) { + flags &= ~(FLAGS_PLUS | FLAGS_SPACE); + } + + // ignore '0' flag when precision is given + if (flags & FLAGS_PRECISION) { + flags &= ~FLAGS_ZEROPAD; + } + + // convert the integer + if ((*format == 'i') || (*format == 'd')) { + // signed + if (flags & FLAGS_LONG_LONG) { +#if defined(PRINTF_SUPPORT_LONG_LONG) + const long long value = va_arg(va, long long); + idx = _ntoa_long_long(out, buffer, idx, maxlen, (unsigned long long)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags); +#endif + } + else if (flags & FLAGS_LONG) { + const long value = va_arg(va, long); + idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned long)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags); + } + else { + const int value = (flags & FLAGS_CHAR) ? (char)va_arg(va, int) : (flags & FLAGS_SHORT) ? (short int)va_arg(va, int) : va_arg(va, int); + idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned int)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags); + } + } + else { + // unsigned + if (flags & FLAGS_LONG_LONG) { +#if defined(PRINTF_SUPPORT_LONG_LONG) + idx = _ntoa_long_long(out, buffer, idx, maxlen, va_arg(va, unsigned long long), false, base, precision, width, flags); +#endif + } + else if (flags & FLAGS_LONG) { + idx = _ntoa_long(out, buffer, idx, maxlen, va_arg(va, unsigned long), false, base, precision, width, flags); + } + else { + const unsigned int value = (flags & FLAGS_CHAR) ? (unsigned char)va_arg(va, unsigned int) : (flags & FLAGS_SHORT) ? (unsigned short int)va_arg(va, unsigned int) : va_arg(va, unsigned int); + idx = _ntoa_long(out, buffer, idx, maxlen, value, false, base, precision, width, flags); + } + } + format++; + break; + } +#if defined(PRINTF_SUPPORT_FLOAT) + case 'f' : + case 'F' : + if (*format == 'F') flags |= FLAGS_UPPERCASE; + idx = _ftoa(out, buffer, idx, maxlen, va_arg(va, double), precision, width, flags); + format++; + break; +#if defined(PRINTF_SUPPORT_EXPONENTIAL) + case 'e': + case 'E': + case 'g': + case 'G': + if ((*format == 'g')||(*format == 'G')) flags |= FLAGS_ADAPT_EXP; + if ((*format == 'E')||(*format == 'G')) flags |= FLAGS_UPPERCASE; + idx = _etoa(out, buffer, idx, maxlen, va_arg(va, double), precision, width, flags); + format++; + break; +#endif // PRINTF_SUPPORT_EXPONENTIAL +#endif // PRINTF_SUPPORT_FLOAT + case 'c' : { + unsigned int l = 1U; + // pre padding + if (!(flags & FLAGS_LEFT)) { + while (l++ < width) { + out(' ', buffer, idx++, maxlen); + } + } + // char output + out((char)va_arg(va, int), buffer, idx++, maxlen); + // post padding + if (flags & FLAGS_LEFT) { + while (l++ < width) { + out(' ', buffer, idx++, maxlen); + } + } + format++; + break; + } + + case 's' : { + const char* p = va_arg(va, char*); + unsigned int l = _strnlen_s(p, precision ? precision : (size_t)-1); + // pre padding + if (flags & FLAGS_PRECISION) { + l = (l < precision ? l : precision); + } + if (!(flags & FLAGS_LEFT)) { + while (l++ < width) { + out(' ', buffer, idx++, maxlen); + } + } + // string output + while ((*p != 0) && (!(flags & FLAGS_PRECISION) || precision--)) { + out(*(p++), buffer, idx++, maxlen); + } + // post padding + if (flags & FLAGS_LEFT) { + while (l++ < width) { + out(' ', buffer, idx++, maxlen); + } + } + format++; + break; + } + + case 'p' : { + width = sizeof(void*) * 2U; + flags |= FLAGS_ZEROPAD | FLAGS_UPPERCASE; +#if defined(PRINTF_SUPPORT_LONG_LONG) + const bool is_ll = sizeof(uintptr_t) == sizeof(long long); + if (is_ll) { + idx = _ntoa_long_long(out, buffer, idx, maxlen, (uintptr_t)va_arg(va, void*), false, 16U, precision, width, flags); + } + else { +#endif + idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned long)((uintptr_t)va_arg(va, void*)), false, 16U, precision, width, flags); +#if defined(PRINTF_SUPPORT_LONG_LONG) + } +#endif + format++; + break; + } + + case '%' : + out('%', buffer, idx++, maxlen); + format++; + break; + + default : + out(*format, buffer, idx++, maxlen); + format++; + break; + } + } + + // termination + out((char)0, buffer, idx < maxlen ? idx : maxlen - 1U, maxlen); + + // return written chars without terminating \0 + return (int)idx; +} + + +/////////////////////////////////////////////////////////////////////////////// + +int printf_(const char* format, ...) +{ + va_list va; + va_start(va, format); + char buffer[1]; + const int ret = _vsnprintf(_out_char, buffer, (size_t)-1, format, va); + va_end(va); + return ret; +} + + +int sprintf_(char* buffer, const char* format, ...) +{ + va_list va; + va_start(va, format); + const int ret = _vsnprintf(_out_buffer, buffer, (size_t)-1, format, va); + va_end(va); + return ret; +} + + +int snprintf_(char* buffer, size_t count, const char* format, ...) +{ + va_list va; + va_start(va, format); + const int ret = _vsnprintf(_out_buffer, buffer, count, format, va); + va_end(va); + return ret; +} + + +int vprintf_(const char* format, va_list va) +{ + char buffer[1]; + return _vsnprintf(_out_char, buffer, (size_t)-1, format, va); +} + + +int vsnprintf_(char* buffer, size_t count, const char* format, va_list va) +{ + return _vsnprintf(_out_buffer, buffer, count, format, va); +} + + +int fctprintf(void (*out)(char character, void* arg), void* arg, const char* format, ...) +{ + va_list va; + va_start(va, format); + const out_fct_wrap_type out_fct_wrap = { out, arg }; + const int ret = _vsnprintf(_out_fct, (char*)(uintptr_t)&out_fct_wrap, (size_t)-1, format, va); + va_end(va); + return ret; +} \ No newline at end of file diff --git a/src/io/printf.h b/src/io/printf.h new file mode 100644 index 0000000..e58f666 --- /dev/null +++ b/src/io/printf.h @@ -0,0 +1,117 @@ +/////////////////////////////////////////////////////////////////////////////// +// \author (c) Marco Paland (info@paland.com) +// 2014-2019, PALANDesign Hannover, Germany +// +// \license The MIT License (MIT) +// +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to deal +// in the Software without restriction, including without limitation the rights +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the Software is +// furnished to do so, subject to the following conditions: +// +// The above copyright notice and this permission notice shall be included in +// all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +// THE SOFTWARE. +// +// \brief Tiny printf, sprintf and snprintf implementation, optimized for speed on +// embedded systems with a very limited resources. +// Use this instead of bloated standard/newlib printf. +// These routines are thread safe and reentrant. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef _PRINTF_H_ +#define _PRINTF_H_ + +#include +#include + + +#ifdef __cplusplus +extern "C" { +#endif + + +/** + * Output a character to a custom device like UART, used by the printf() function + * This function is declared here only. You have to write your custom implementation somewhere + * \param character Character to output + */ +void _putchar(char character); + + +/** + * Tiny printf implementation + * You have to implement _putchar if you use printf() + * To avoid conflicts with the regular printf() API it is overridden by macro defines + * and internal underscore-appended functions like printf_() are used + * \param format A string that specifies the format of the output + * \return The number of characters that are written into the array, not counting the terminating null character + */ +#define printf printf_ +int printf_(const char* format, ...); + + +/** + * Tiny sprintf implementation + * Due to security reasons (buffer overflow) YOU SHOULD CONSIDER USING (V)SNPRINTF INSTEAD! + * \param buffer A pointer to the buffer where to store the formatted string. MUST be big enough to store the output! + * \param format A string that specifies the format of the output + * \return The number of characters that are WRITTEN into the buffer, not counting the terminating null character + */ +#define sprintf sprintf_ +int sprintf_(char* buffer, const char* format, ...); + + +/** + * Tiny snprintf/vsnprintf implementation + * \param buffer A pointer to the buffer where to store the formatted string + * \param count The maximum number of characters to store in the buffer, including a terminating null character + * \param format A string that specifies the format of the output + * \param va A value identifying a variable arguments list + * \return The number of characters that COULD have been written into the buffer, not counting the terminating + * null character. A value equal or larger than count indicates truncation. Only when the returned value + * is non-negative and less than count, the string has been completely written. + */ +#define snprintf snprintf_ +#define vsnprintf vsnprintf_ +int snprintf_(char* buffer, size_t count, const char* format, ...); +int vsnprintf_(char* buffer, size_t count, const char* format, va_list va); + + +/** + * Tiny vprintf implementation + * \param format A string that specifies the format of the output + * \param va A value identifying a variable arguments list + * \return The number of characters that are WRITTEN into the buffer, not counting the terminating null character + */ +#define vprintf vprintf_ +int vprintf_(const char* format, va_list va); + + +/** + * printf with output function + * You may use this as dynamic alternative to printf() with its fixed _putchar() output + * \param out An output function which takes one character and an argument pointer + * \param arg An argument pointer for user data passed to output function + * \param format A string that specifies the format of the output + * \return The number of characters that are sent to the output function, not counting the terminating null character + */ +int fctprintf(void (*out)(char character, void* arg), void* arg, const char* format, ...); + + +#ifdef __cplusplus +} +#endif + + +#endif // _PRINTF_H_ \ No newline at end of file diff --git a/src/term.c b/src/io/term.c similarity index 95% rename from src/term.c rename to src/io/term.c index dd1e397..f2a913c 100644 --- a/src/term.c +++ b/src/io/term.c @@ -87,6 +87,12 @@ static void putchar(char c) cursor.x++; } +// Overhead that could be avoided, right? +void _putchar(char character) +{ + putchar(character); +} + // Debug-printing void kputs(const char* str) { diff --git a/src/term.h b/src/io/term.h similarity index 100% rename from src/term.h rename to src/io/term.h diff --git a/src/kmain.c b/src/kmain.c index 3c321eb..d818962 100644 --- a/src/kmain.c +++ b/src/kmain.c @@ -1,7 +1,8 @@ #include #include #include -#include "term.h" +#include "io/term.h" +#include "io/printf.h" // Limine version used __attribute__((used, section(".limine_requests"))) @@ -111,7 +112,7 @@ void kmain() if (term_init()) hcf(); // Draw something - kputs("Hello, world!"); + printf("%s, %s!", "Hello", "world"); hcf(); } -- 2.49.1 From b1b4bd02219ac9dffc16ebe34cf134a3d80b6da9 Mon Sep 17 00:00:00 2001 From: xamidev Date: Sun, 21 Dec 2025 15:39:55 +0100 Subject: [PATCH 3/3] Clearer README --- README.md | 25 ++++++++----------------- 1 file changed, 8 insertions(+), 17 deletions(-) diff --git a/README.md b/README.md index 18a5428..60fb593 100644 --- a/README.md +++ b/README.md @@ -1,25 +1,16 @@ -# pepperOS +# pepperOS: "will never be done" -will never be done +## Trying the kernel -To compile the kernel and make an ISO image file: +First install the dependencies: `sudo apt install xorriso make qemu-system` -``` -make build-iso -``` +Then, to compile the kernel and make an ISO image file: `make build-iso` +To run it with QEMU, `make run` -Then it can be run with `qemu-system-x86_64 kernel.iso`. +## Thanks - -### Kernel conventions - -Functions that return an integer as status of success/failure will return: -- 0 if everything went correctly -- a negative value if something went wrong - -### Thanks - -PepperOS wouldn't be possible without: +PepperOS wouldn't be possible without the following freely-licensed software: - the [Limine](https://codeberg.org/Limine/Limine) portable bootloader - Marco Paland's freestanding [printf implementation](https://github.com/mpaland) +- the [ZAP](https://www.zap.org.au/projects/console-fonts-zap/) PSF console fonts \ No newline at end of file -- 2.49.1