From a78033acc941fc4bcf6188f1d48fd8e012673fff Mon Sep 17 00:00:00 2001 From: EmulatedSeasons <89668582+EmulatedSeasons@users.noreply.github.com> Date: Thu, 15 Jun 2023 22:36:39 -0400 Subject: initial commit --- kernel/std/README.txt | 5 ++++ kernel/std/abort.c | 11 +++++++ kernel/std/memcmp.c | 13 +++++++++ kernel/std/memcpy.c | 9 ++++++ kernel/std/memmove.c | 14 +++++++++ kernel/std/memset.c | 8 ++++++ kernel/std/printf.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++ kernel/std/putchar.c | 9 ++++++ kernel/std/puts.c | 5 ++++ kernel/std/strlen.c | 9 ++++++ 10 files changed, 163 insertions(+) create mode 100644 kernel/std/README.txt create mode 100644 kernel/std/abort.c create mode 100644 kernel/std/memcmp.c create mode 100644 kernel/std/memcpy.c create mode 100644 kernel/std/memmove.c create mode 100644 kernel/std/memset.c create mode 100644 kernel/std/printf.c create mode 100644 kernel/std/putchar.c create mode 100644 kernel/std/puts.c create mode 100644 kernel/std/strlen.c (limited to 'kernel/std') diff --git a/kernel/std/README.txt b/kernel/std/README.txt new file mode 100644 index 0000000..2ad6cb4 --- /dev/null +++ b/kernel/std/README.txt @@ -0,0 +1,5 @@ +a temporary(?) libc for the kernel + +code from meaty skeleton from osdev.org + +todo: change back to .c and seperate it as a library or something \ No newline at end of file diff --git a/kernel/std/abort.c b/kernel/std/abort.c new file mode 100644 index 0000000..83873e8 --- /dev/null +++ b/kernel/std/abort.c @@ -0,0 +1,11 @@ +#include +#include + +__attribute__((__noreturn__)) +void abort(void) { + // TODO: Add proper kernel panic. + printf("kernel: panic: abort()\n"); + asm volatile("hlt"); + while (1) { } + __builtin_unreachable(); +} \ No newline at end of file diff --git a/kernel/std/memcmp.c b/kernel/std/memcmp.c new file mode 100644 index 0000000..93141e1 --- /dev/null +++ b/kernel/std/memcmp.c @@ -0,0 +1,13 @@ +#include + +int memcmp(const void* aptr, const void* bptr, size_t size) { + const unsigned char* a = (const unsigned char*) aptr; + const unsigned char* b = (const unsigned char*) bptr; + for (size_t i = 0; i < size; i++) { + if (a[i] < b[i]) + return -1; + else if (b[i] < a[i]) + return 1; + } + return 0; +} \ No newline at end of file diff --git a/kernel/std/memcpy.c b/kernel/std/memcpy.c new file mode 100644 index 0000000..7e09be7 --- /dev/null +++ b/kernel/std/memcpy.c @@ -0,0 +1,9 @@ +#include + +void* memcpy(void* restrict dstptr, const void* restrict srcptr, size_t size) { + unsigned char* dst = (unsigned char*) dstptr; + const unsigned char* src = (const unsigned char*) srcptr; + for (size_t i=0; i < size; i++) + dst[i] = src[i]; + return dstptr; +} \ No newline at end of file diff --git a/kernel/std/memmove.c b/kernel/std/memmove.c new file mode 100644 index 0000000..98c787f --- /dev/null +++ b/kernel/std/memmove.c @@ -0,0 +1,14 @@ +#include + +void* memmove(void* dstptr, const void* srcptr, size_t size) { + unsigned char* dst = (unsigned char*) dstptr; + const unsigned char* src = (const unsigned char*) srcptr; + if (dst < src) { + for (size_t i = 0; i < size; i++) + dst[i] = src[i]; + } else { + for (size_t i = size; i != 0; i--) + dst[i-1] = src[i-1]; + } + return dstptr; +} \ No newline at end of file diff --git a/kernel/std/memset.c b/kernel/std/memset.c new file mode 100644 index 0000000..67dadfe --- /dev/null +++ b/kernel/std/memset.c @@ -0,0 +1,8 @@ +#include + +void* memset(void* bufptr, int value, size_t size) { + unsigned char* buf = (unsigned char*) bufptr; + for (size_t i = 0; i < size; i++) + buf[i] = (unsigned char) value; + return bufptr; +} \ No newline at end of file diff --git a/kernel/std/printf.c b/kernel/std/printf.c new file mode 100644 index 0000000..c383cad --- /dev/null +++ b/kernel/std/printf.c @@ -0,0 +1,80 @@ +#include +#include +#include +#include +#include + +static bool print(const char* data, size_t length) { + const unsigned char* bytes = (const unsigned char*) data; + for (size_t i = 0; i < length; i++) + if (putchar(bytes[i]) == EOF) + return false; + return true; +} + +int printf(const char* restrict format, ...) { + va_list parameters; + va_start(parameters, format); + + int written = 0; + + while (*format != '\0') { + size_t maxrem = INT_MAX - written; + + if (format[0] != '%' || format[1] == '%') { + if (format[0] == '%') + format++; + size_t amount = 1; + while (format[amount] && format[amount] != '%') + amount++; + if (maxrem < amount) { + // TODO: Set errno to EOVERFLOW. + return -1; + } + if (!print(format, amount)) + return -1; + format += amount; + written += amount; + continue; + } + + const char* format_begun_at = format++; + + if (*format == 'c') { + format++; + char c = (char) va_arg(parameters, int /* char promotes to int */); + if (!maxrem) { + // TODO: Set errno to EOVERFLOW. + return -1; + } + if (!print(&c, sizeof(c))) + return -1; + written++; + } else if (*format == 's') { + format++; + const char* str = va_arg(parameters, const char*); + size_t len = strlen(str); + if (maxrem < len) { + // TODO: Set errno to EOVERFLOW. + return -1; + } + if (!print(str, len)) + return -1; + written += len; + } else { + format = format_begun_at; + size_t len = strlen(format); + if (maxrem < len) { + // TODO: Set errno to EOVERFLOW. + return -1; + } + if (!print(format, len)) + return -1; + written += len; + format += len; + } + } + + va_end(parameters); + return written; +} \ No newline at end of file diff --git a/kernel/std/putchar.c b/kernel/std/putchar.c new file mode 100644 index 0000000..c5a7976 --- /dev/null +++ b/kernel/std/putchar.c @@ -0,0 +1,9 @@ +#include + +#include + +int putchar(int ic) { + char c = (char) ic; + terminal_write(&c, sizeof(c)); + return ic; +} \ No newline at end of file diff --git a/kernel/std/puts.c b/kernel/std/puts.c new file mode 100644 index 0000000..8c8c036 --- /dev/null +++ b/kernel/std/puts.c @@ -0,0 +1,5 @@ +#include + +int puts(const char* string) { + return printf("%s\n", string); +} \ No newline at end of file diff --git a/kernel/std/strlen.c b/kernel/std/strlen.c new file mode 100644 index 0000000..441622a --- /dev/null +++ b/kernel/std/strlen.c @@ -0,0 +1,9 @@ +#include + +size_t strlen(const char* str) { + size_t len = 0; + while (str[len]) { + ++len; + } + return len; +} \ No newline at end of file -- cgit v1.2.3-70-g09d2