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-rw-r--r--Makefile9
-rw-r--r--src/init/main.c50
-rw-r--r--src/init/stdlib.c53
-rw-r--r--src/init/stdlib.h4
-rw-r--r--src/init/syscalls.c8
-rw-r--r--src/kernel/arch/i386/ata.c131
-rw-r--r--src/kernel/arch/i386/ata.h4
-rw-r--r--src/kernel/arch/i386/boot.c7
-rw-r--r--src/kernel/arch/i386/interrupts/isr.c21
-rw-r--r--src/kernel/arch/i386/port_io.h14
-rw-r--r--src/kernel/arch/i386/tty/serial.c28
-rw-r--r--src/kernel/proc.c19
-rw-r--r--src/kernel/proc.h7
-rw-r--r--src/kernel/syscalls.c24
-rw-r--r--src/shared/syscalls.h8
15 files changed, 295 insertions, 92 deletions
diff --git a/Makefile b/Makefile
index 08bb5d6..886de4b 100644
--- a/Makefile
+++ b/Makefile
@@ -18,8 +18,10 @@ endef
.PHONY: all boot debug lint check clean
all: out/boot.iso check
-boot: all
- qemu-system-i386 -cdrom out/boot.iso $(QFLAGS) -no-shutdown
+boot: all out/hdd
+ qemu-system-i386 -cdrom out/boot.iso $(QFLAGS) -no-shutdown \
+ -drive file=out/hdd,format=raw,media=disk
+
debug: all
qemu-system-i386 -cdrom out/boot.iso $(QFLAGS) -s -S &
@@ -59,6 +61,9 @@ out/fs/boot/grub/grub.cfg: grub.cfg
@mkdir -p $(@D)
@cp $< $@
+out/hdd:
+ @dd if=/dev/zero of=$@ bs=512 count=70000
+
out/obj/%.s.o: src/%.s
@mkdir -p $(@D)
diff --git a/src/init/main.c b/src/init/main.c
index 5c798d2..401e4a0 100644
--- a/src/init/main.c
+++ b/src/init/main.c
@@ -1,10 +1,10 @@
+#include <init/stdlib.h>
#include <init/tar.h>
#include <shared/flags.h>
#include <shared/syscalls.h>
#include <stdint.h>
#define argify(str) str, sizeof(str) - 1
-#define log(str) _syscall_write(tty_fd, argify(str), 0)
extern char _bss_start; // provided by the linker
extern char _bss_end;
@@ -23,7 +23,7 @@ int main(void) {
tty_fd = _syscall_open("/tty", sizeof("/tty") - 1);
if (tty_fd < 0)
- _syscall_exit(argify("couldn't open tty"));
+ _syscall_exit(1);
fs_test();
test_await();
@@ -32,7 +32,7 @@ int main(void) {
while (_syscall_read(tty_fd, &c, 1, 0))
_syscall_write(tty_fd, &c, 1, 0);
- _syscall_exit(argify("my job here is done."));
+ _syscall_exit(0);
}
void read_file(const char *path, size_t len) {
@@ -41,9 +41,9 @@ void read_file(const char *path, size_t len) {
int buf_len = 64;
_syscall_write(tty_fd, path, len, 0);
- log(": ");
+ printf(": ");
if (fd < 0) {
- log("couldn't open.\n");
+ printf("couldn't open.\n");
return;
}
@@ -64,7 +64,7 @@ void fs_test(void) {
}
// parent: accesses the fs
- log("\n\n");
+ printf("\n\n");
// the trailing slash should be ignored by mount()
_syscall_mount(front, argify("/init/"));
read_file(argify("/init/fake.txt"));
@@ -72,30 +72,36 @@ void fs_test(void) {
read_file(argify("/init/2.txt"));
read_file(argify("/init/dir/3.txt"));
- log("\nshadowing /init/dir...\n");
+ printf("\nshadowing /init/dir...\n");
_syscall_mount(-1, argify("/init/dir"));
read_file(argify("/init/fake.txt"));
read_file(argify("/init/1.txt"));
read_file(argify("/init/2.txt"));
read_file(argify("/init/dir/3.txt"));
- log("\n");
+ printf("\n");
}
void test_await(void) {
- char buf[16];
- int len;
-
- // the child immediately dies
- if (!_syscall_fork())
- _syscall_exit(argify("i'm dead"));
- if (!_syscall_fork())
- _syscall_exit(argify("i'm also dead"));
-
- while ((len = _syscall_await(buf, 16)) >= 0) {
- log("await returned: ");
- _syscall_write(tty_fd, buf, len, 0);
- log("\n");
+ int ret;
+
+ // regular exit()s
+ if (!_syscall_fork()) _syscall_exit(69);
+ if (!_syscall_fork()) _syscall_exit(420);
+
+ // faults
+ if (!_syscall_fork()) { // invalid memory access
+ asm volatile("movb $69, 0" ::: "memory");
+ printf("this shouldn't happen");
+ _syscall_exit(-1);
}
- log("await: negative len\n");
+ if (!_syscall_fork()) { // #GP
+ asm volatile("hlt" ::: "memory");
+ printf("this shouldn't happen");
+ _syscall_exit(-1);
+ }
+
+ while ((ret = _syscall_await()) != ~0)
+ printf("await returned: %x\n", ret);
+ printf("await: no more children\n");
}
diff --git a/src/init/stdlib.c b/src/init/stdlib.c
index 6ed5a0a..a60854b 100644
--- a/src/init/stdlib.c
+++ b/src/init/stdlib.c
@@ -1,4 +1,6 @@
#include <init/stdlib.h>
+#include <shared/syscalls.h>
+#include <stdarg.h>
int memcmp(const void *s1, const void *s2, size_t n) {
const unsigned char *c1 = s1, *c2 = s2;
@@ -10,3 +12,54 @@ int memcmp(const void *s1, const void *s2, size_t n) {
}
return 0;
}
+
+size_t strlen(const char *s) {
+ size_t c = 0;
+ while (*s++) c++;
+ return c;
+}
+
+int printf(const char *fmt, ...) {
+ const char *seg = fmt; // beginning of the current segment
+ int total = 0;
+ va_list argp;
+ va_start(argp, fmt);
+ for (;;) {
+ char c = *fmt++;
+ switch (c) {
+ case '\0':
+ // TODO don't assume that stdout is @ fd 0
+ _syscall_write(0, seg, fmt - seg - 1, 0);
+ return total + (fmt - seg - 1);
+
+ case '%':
+ _syscall_write(0, seg, fmt - seg - 1, 0);
+ total += fmt - seg - 1;
+ c = *fmt++;
+ switch (c) {
+ case 's':
+ const char *s = va_arg(argp, char*);
+ _syscall_write(0, s, strlen(s), 0);
+ total += strlen(s);
+ break;
+
+ case 'x':
+ unsigned int n = va_arg(argp, int);
+ size_t i = 4; // nibbles * 4
+ while (n >> i && i < (sizeof(int) * 8))
+ i += 4;
+
+ while (i > 0) {
+ i -= 4;
+ char h = '0' + ((n >> i) & 0xf);
+ if (h > '9') h += 'a' - '9' - 1;
+ _syscall_write(0, &h, 1, 0);
+ total++;
+ }
+ break;
+ }
+ seg = fmt;
+ break;
+ }
+ }
+}
diff --git a/src/init/stdlib.h b/src/init/stdlib.h
index 1cabc7a..3e56beb 100644
--- a/src/init/stdlib.h
+++ b/src/init/stdlib.h
@@ -5,3 +5,7 @@
// stb-style header file
int memcmp(const void *s1, const void *s2, size_t n);
+
+size_t strlen(const char *s);
+
+int printf(const char *fmt, ...);
diff --git a/src/init/syscalls.c b/src/init/syscalls.c
index f32594e..57a7344 100644
--- a/src/init/syscalls.c
+++ b/src/init/syscalls.c
@@ -1,8 +1,8 @@
// this file could probably just get generated by a script
#include <shared/syscalls.h>
-_Noreturn void _syscall_exit(const char __user *msg, size_t len) {
- _syscall(_SYSCALL_EXIT, (int)msg, len, 0, 0);
+_Noreturn void _syscall_exit(int ret) {
+ _syscall(_SYSCALL_EXIT, ret, 0, 0, 0);
__builtin_unreachable();
}
@@ -10,8 +10,8 @@ int _syscall_fork(void) {
return _syscall(_SYSCALL_FORK, 0, 0, 0, 0);
}
-int _syscall_await(char __user *buf, int len) {
- return _syscall(_SYSCALL_AWAIT, (int)buf, (int)len, 0, 0);
+int _syscall_await(void) {
+ return _syscall(_SYSCALL_AWAIT, 0, 0, 0, 0);
}
handle_t _syscall_open(const char __user *path, int len) {
diff --git a/src/kernel/arch/i386/ata.c b/src/kernel/arch/i386/ata.c
new file mode 100644
index 0000000..9224ed6
--- /dev/null
+++ b/src/kernel/arch/i386/ata.c
@@ -0,0 +1,131 @@
+#include <kernel/arch/i386/ata.h>
+#include <kernel/arch/i386/port_io.h>
+#include <kernel/panic.h>
+#include <stdbool.h>
+
+#include <kernel/arch/io.h>
+
+static struct {
+ enum {
+ DEV_UNKNOWN,
+ DEV_PATA,
+ DEV_PATAPI,
+ } type;
+ uint32_t sectors;
+} ata_drives[4];
+
+enum {
+ LBAlo = 3,
+ LBAmid = 4,
+ LBAhi = 5,
+ DRV = 6,
+ CMD = 7,
+ STATUS = 7,
+
+ /* note: the OSDev wiki uses a different base port for the control port
+ * however i can just use this offset and stuff will just work tm */
+ CTRL = 0x206,
+}; // offsets
+
+// get I/O port base for drive
+static uint16_t ata_iobase(int drive) {
+ bool secondary = drive&2;
+ return secondary ? 0x170 : 0x1F0;
+}
+
+static void ata_400ns(void) {
+ uint16_t base = ata_iobase(0); // doesn't matter
+ for (int i = 0; i < 4; i++)
+ port_in8(base + STATUS);
+}
+
+static void ata_driveselect(int drive, int block) {
+ uint8_t v = 0xE0;
+ if (drive&1) // slave?
+ v |= 0x10; // set drive number bit
+ // TODO account for block
+ port_out8(ata_iobase(drive) + DRV, v);
+}
+
+static void ata_softreset(int drive) {
+ uint16_t iobase = ata_iobase(drive);
+ port_out8(iobase + CTRL, 4);
+ port_out8(iobase + CTRL, 0);
+ ata_400ns();
+
+ uint16_t timeout = 10000;
+ while (--timeout) { // TODO separate polling function
+ uint8_t v = port_in8(iobase + STATUS);
+ if (v & 0x80) continue; // still BSY, continue
+ if (v & 0x40) break; // RDY, break
+ // TODO check for ERR
+ }
+}
+
+static void ata_detecttype(int drive) {
+ ata_softreset(drive);
+ ata_driveselect(drive, 0);
+ ata_400ns();
+ switch (port_in8(ata_iobase(drive) + LBAmid)) {
+ case 0:
+ ata_drives[drive].type = DEV_PATA;
+ break;
+ case 0x14:
+ ata_drives[drive].type = DEV_PATAPI;
+ break;
+ default:
+ ata_drives[drive].type = DEV_UNKNOWN;
+ break;
+ }
+}
+
+static bool ata_identify(int drive) {
+ uint16_t iobase = ata_iobase(drive);
+ uint16_t data[256];
+ uint8_t v;
+
+ ata_driveselect(drive, 0);
+ for (int i = 2; i < 6; i++)
+ port_out8(iobase + i, 0);
+ switch (ata_drives[drive].type) {
+ case DEV_PATA:
+ port_out8(iobase + CMD, 0xEC); // IDENTIFY
+ break;
+ case DEV_PATAPI:
+ port_out8(iobase + CMD, 0xA1); // IDENTIFY PACKET DEVICE
+ break;
+ default: panic_invalid_state();
+ }
+
+ v = port_in8(iobase + STATUS);
+ if (v == 0) return false; // nonexistent drive
+ while (port_in8(iobase + STATUS) & 0x80);
+
+ /* pool until bit 3 (DRQ) or 0 (ERR) is set */
+ while (!((v = port_in8(iobase + STATUS) & 0x9)));
+ if (v & 1) return false; /* ERR was set, bail */
+
+ for (int i = 0; i < 256; i++)
+ data[i] = port_in16(iobase);
+ ata_drives[drive].sectors = data[60] | (data[61] << 16);
+ return true;
+}
+
+void ata_init(void) {
+ tty_const("\n");
+ for (int i = 0; i < 4; i++) {
+ tty_const("probing drive ");
+ _tty_var(i);
+ ata_detecttype(i);
+ if (ata_drives[i].type != DEV_UNKNOWN) {
+ if (ata_identify(i)) {
+ tty_const(" - ");
+ _tty_var(ata_drives[i].sectors);
+ tty_const(" sectors (512b)");
+ } else {
+ tty_const(" identify failed");
+ }
+ }
+ tty_const("\n");
+ }
+}
diff --git a/src/kernel/arch/i386/ata.h b/src/kernel/arch/i386/ata.h
new file mode 100644
index 0000000..9137cdb
--- /dev/null
+++ b/src/kernel/arch/i386/ata.h
@@ -0,0 +1,4 @@
+#pragma once
+#include <stdint.h>
+
+void ata_init(void);
diff --git a/src/kernel/arch/i386/boot.c b/src/kernel/arch/i386/boot.c
index bd2a00b..94e9e2f 100644
--- a/src/kernel/arch/i386/boot.c
+++ b/src/kernel/arch/i386/boot.c
@@ -1,4 +1,5 @@
#include <kernel/arch/generic.h>
+#include <kernel/arch/i386/ata.h>
#include <kernel/arch/i386/boot.h>
#include <kernel/arch/i386/gdt.h>
#include <kernel/arch/i386/interrupts/idt.h>
@@ -15,7 +16,9 @@ void kmain_early(struct multiboot_info *multiboot) {
gdt_init();
tty_const("idt...");
idt_init();
-
+ tty_const("ata...");
+ ata_init();
+
{ // find the init module
struct multiboot_mod *module = &multiboot->mods[0];
if (multiboot->mods_count < 1) {
@@ -25,6 +28,6 @@ void kmain_early(struct multiboot_info *multiboot) {
info.init.at = module->start;
info.init.size = module->end - module->start;
}
-
+
kmain(info);
}
diff --git a/src/kernel/arch/i386/interrupts/isr.c b/src/kernel/arch/i386/interrupts/isr.c
index dacecba..9d8bb6c 100644
--- a/src/kernel/arch/i386/interrupts/isr.c
+++ b/src/kernel/arch/i386/interrupts/isr.c
@@ -1,29 +1,24 @@
#include <kernel/arch/i386/interrupts/isr.h>
#include <kernel/arch/io.h>
#include <kernel/panic.h>
+#include <kernel/proc.h>
#include <stdbool.h>
#include <stdint.h>
-#define log_n_panic(x) {tty_const(x); panic_unimplemented();} // TODO kill the current process instead of panicking
-
bool isr_test_interrupt_called = false;
void isr_stage3(int interrupt) {
switch (interrupt) {
- case 0x08: log_n_panic("#DF"); // double fault
- case 0x0D: log_n_panic("#GP"); // general protection fault
- case 0x0E: { // page fault
- int cr2;
- tty_const("#PF at ");
- asm ("mov %%cr2, %0;" : "=r"(cr2) ::);
- _tty_var(cr2);
- panic_unimplemented();
- }
-
+ case 0x08: // double fault
+ tty_const("#DF");
+ panic_invalid_state();
case 0x34:
isr_test_interrupt_called = true;
return;
- default: log_n_panic("unknown interrupt");
+ default:
+ // TODO check if the exception was in the kernel
+ process_kill(process_current, interrupt);
+ process_switch_any();
}
}
diff --git a/src/kernel/arch/i386/port_io.h b/src/kernel/arch/i386/port_io.h
index a4d640f..eac9331 100644
--- a/src/kernel/arch/i386/port_io.h
+++ b/src/kernel/arch/i386/port_io.h
@@ -1,12 +1,22 @@
#include <stdint.h>
-static inline void port_outb(uint16_t port, uint8_t val) {
+static inline void port_out8(uint16_t port, uint8_t val) {
asm volatile("outb %0, %1" : : "a" (val), "Nd" (port));
}
-static inline uint8_t port_inb(uint16_t port) {
+static inline void port_out16(uint16_t port, uint16_t val) {
+ asm volatile("outw %0, %1" : : "a" (val), "Nd" (port));
+}
+
+static inline uint8_t port_in8(uint16_t port) {
uint8_t val;
asm volatile("inb %1, %0" : "=a" (val) : "Nd" (port));
return val;
}
+static inline uint16_t port_in16(uint16_t port) {
+ uint16_t val;
+ asm volatile("inw %1, %0" : "=a" (val) : "Nd" (port));
+ return val;
+}
+
diff --git a/src/kernel/arch/i386/tty/serial.c b/src/kernel/arch/i386/tty/serial.c
index 2b89ecf..f9bb252 100644
--- a/src/kernel/arch/i386/tty/serial.c
+++ b/src/kernel/arch/i386/tty/serial.c
@@ -7,37 +7,37 @@ static const int COM1 = 0x3f8;
static void serial_selftest(void) {
char b = 0x69;
- port_outb(COM1 + 4, 0b00011110); // enable loopback mode
- port_outb(COM1, b);
- assert(port_inb(COM1) == b);
+ port_out8(COM1 + 4, 0b00011110); // enable loopback mode
+ port_out8(COM1, b);
+ assert(port_in8(COM1) == b);
}
void serial_init(void) {
// see https://www.sci.muni.cz/docs/pc/serport.txt
- port_outb(COM1 + 1, 0x00); // disable interrupts, we won't be using them
+ port_out8(COM1 + 1, 0x00); // disable interrupts, we won't be using them
// set baud rate divisor
- port_outb(COM1 + 3, 0b10000000); // enable DLAB
- port_outb(COM1 + 0, 0x01); // divisor = 1 (low byte)
- port_outb(COM1 + 1, 0x00); // (high byte)
+ port_out8(COM1 + 3, 0b10000000); // enable DLAB
+ port_out8(COM1 + 0, 0x01); // divisor = 1 (low byte)
+ port_out8(COM1 + 1, 0x00); // (high byte)
- port_outb(COM1 + 3, 0b00000011); // 8 bits, no parity, one stop bit
- port_outb(COM1 + 2, 0b11000111); // enable FIFO with 14-bit trigger level (???)
+ port_out8(COM1 + 3, 0b00000011); // 8 bits, no parity, one stop bit
+ port_out8(COM1 + 2, 0b11000111); // enable FIFO with 14-bit trigger level (???)
serial_selftest();
- port_outb(COM1 + 4, 0b00001111); // enable everything in the MCR
+ port_out8(COM1 + 4, 0b00001111); // enable everything in the MCR
}
static void serial_putchar(char c) {
- while ((port_inb(COM1 + 5) & 0x20) == 0); // wait for THRE
- port_outb(COM1, c);
+ while ((port_in8(COM1 + 5) & 0x20) == 0); // wait for THRE
+ port_out8(COM1, c);
}
char serial_read(void) {
- while ((port_inb(COM1 + 5) & 0x01) == 0); // wait for DR
- return port_inb(COM1);
+ while ((port_in8(COM1 + 5) & 0x01) == 0); // wait for DR
+ return port_in8(COM1);
}
void serial_write(const char *buf, size_t len) {
diff --git a/src/kernel/proc.c b/src/kernel/proc.c
index b9f96c8..17af0cd 100644
--- a/src/kernel/proc.c
+++ b/src/kernel/proc.c
@@ -103,10 +103,15 @@ handle_t process_find_handle(struct process *proc) {
return handle;
}
+void process_kill(struct process *proc, int ret) {
+ proc->state = PS_DEAD;
+ proc->death_msg = ret;
+ process_try2collect(proc);
+}
+
int process_try2collect(struct process *dead) {
struct process *parent = dead->parent;
- int len, ret;
- bool res;
+ int ret;
assert(dead->state == PS_DEAD);
@@ -115,16 +120,12 @@ int process_try2collect(struct process *dead) {
dead->state = PS_DEADER;
parent->state = PS_RUNNING;
- len = min(parent->death_msg.len, dead->death_msg.len);
- res = virt_cpy(
- parent->pages, parent->death_msg.buf,
- dead->pages, dead->death_msg.buf, len);
-
- ret = res ? len : 0;
+ ret = dead->death_msg;
regs_savereturn(&parent->regs, ret);
return ret;
default:
- return -1;
+ return -1; // this return value isn't used anywhere
+ // TODO enforce that, somehow? idk
}
}
diff --git a/src/kernel/proc.h b/src/kernel/proc.h
index 82bb59a..7c338bb 100644
--- a/src/kernel/proc.h
+++ b/src/kernel/proc.h
@@ -26,10 +26,7 @@ struct process {
// saved value, meaning depends on .state
union {
- struct { // PS_DEAD, PS_WAITS4CHILDDEATH
- char __user *buf;
- size_t len;
- } death_msg;
+ int death_msg; // PS_DEAD
struct vfs_request pending_req; // PS_WAITS4FS
struct {
char __user *buf;
@@ -56,6 +53,8 @@ _Noreturn void process_switch_any(void); // switches to any running process
struct process *process_find(enum process_state);
handle_t process_find_handle(struct process *proc); // finds the first free handle
+void process_kill(struct process *proc, int ret);
+
/** Tries to transistion from PS_DEAD to PS_DEADER.
* @return a nonnegative length of the quit message if successful, a negative val otherwise*/
int process_try2collect(struct process *dead);
diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c
index 1b91eb7..22bf1f6 100644
--- a/src/kernel/syscalls.c
+++ b/src/kernel/syscalls.c
@@ -8,28 +8,20 @@
#include <shared/syscalls.h>
#include <stdint.h>
-_Noreturn void _syscall_exit(const char __user *msg, size_t len) {
- process_current->state = PS_DEAD;
- process_current->death_msg.buf = (userptr_t) msg; // discarding const
- process_current->death_msg.len = len;
- process_try2collect(process_current);
+_Noreturn void _syscall_exit(int ret) {
+ process_kill(process_current, ret);
process_switch_any();
}
-int _syscall_await(char __user *buf, int len) {
+int _syscall_await(void) {
bool has_children = false;
process_current->state = PS_WAITS4CHILDDEATH;
- process_current->death_msg.buf = buf;
- process_current->death_msg.len = len;
// find any already dead children
for (struct process *iter = process_current->child;
iter; iter = iter->sibling) {
- if (iter->state == PS_DEAD) {
- int ret = process_try2collect(iter);
- assert(ret >= 0);
- return ret;
- }
+ if (iter->state == PS_DEAD)
+ return process_try2collect(iter);
if (iter->state != PS_DEADER)
has_children = true;
}
@@ -38,7 +30,7 @@ int _syscall_await(char __user *buf, int len) {
process_switch_any(); // wait until a child dies
else {
process_current->state = PS_RUNNING;
- return -1; // error
+ return ~0; // TODO errno
}
}
@@ -276,9 +268,9 @@ int _syscall_memflag(void __user *addr, size_t len, int flags) {
int _syscall(int num, int a, int b, int c, int d) {
switch (num) {
case _SYSCALL_EXIT:
- _syscall_exit((userptr_t)a, b);
+ _syscall_exit(a);
case _SYSCALL_AWAIT:
- return _syscall_await((userptr_t)a, b);
+ return _syscall_await();
case _SYSCALL_FORK:
return _syscall_fork();
case _SYSCALL_OPEN:
diff --git a/src/shared/syscalls.h b/src/shared/syscalls.h
index 44a2f5d..3a21b66 100644
--- a/src/shared/syscalls.h
+++ b/src/shared/syscalls.h
@@ -27,12 +27,12 @@ int _syscall(int, int, int, int, int);
/** Kills the current process.
* TODO: what happens to the children?
*/
-_Noreturn void _syscall_exit(const char __user *msg, size_t len);
+_Noreturn void _syscall_exit(int ret);
-/** Waits for a child to exit, putting its exit message into *buf.
- * @return the length of the message
+/** Waits for a child to exit.
+ * @return the value the child passed to exit()
*/
-int _syscall_await(char __user *buf, int len);
+int _syscall_await(void);
/** Creates a copy of the current process, and executes it.
* All user memory pages get copied too.
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-23 03:32:59 +0000