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#include "paging.h"
#include "window.h"
#include "drive.h"
#include "panic.h"
#include "cmos.h"
#include "pmap.h"
#include "task.h"
#include "util.h"
#include "elf.h"
#include "idt.h"
#include "kbd.h"
#include "log.h"
enum {
IDT_PRESENT = 0x80,
IDT_INT = 0x0e,
};
struct idt_entry {
uint16_t addr_low;
uint16_t cs;
uint8_t zero;
uint8_t flags;
uint16_t addr_high;
} __attribute__ ((packed));
struct idt_entry idt[256];
struct {
uint16_t limit;
uint32_t start;
} __attribute__ ((packed)) idtr = {
.limit = 256 * sizeof(struct idt_entry) - 1,
.start = (uint32_t)idt
};
bool verify_file_handle(uint32_t handle, struct drive **d, uint32_t *f) {
*d = drives + (handle >> 24);
*f = handle & 0x00ffffff;
if (!*f || (*d >= drives + n_drives)) {
logf(LOG_WARN, "syscall with file handle 0x%h", handle);
return false;
}
else
return true;
}
uint32_t sc_open_file(const char *path) {
struct drive *did;
const char *sub;
map_path(path, &did, &sub);
if (!did)
return 0;
const file_id_t fid = did->get_file(did, sub);
return fid ? ((did - drives) << 24) + fid : 0;
}
void sc_close_file(uint32_t handle) {
struct drive *d;
uint32_t f;
if (verify_file_handle(handle, &d, &f))
d->free_file(d, f);
}
uint32_t sc_file_get_size(uint32_t handle) {
struct drive *d;
uint32_t f;
if (verify_file_handle(handle, &d, &f))
return d->get_file_length(d, f);
else
return 0;
}
void sc_file_set_size(uint32_t handle, uint32_t new_size) {
struct drive *d;
uint32_t f;
if (verify_file_handle(handle, &d, &f))
d->set_file_length(d, f, new_size);
}
uint32_t sc_file_read(uint32_t handle, uint32_t file_offset, uint32_t count, void *buffer) {
struct drive *d;
uint32_t f;
if (verify_file_handle(handle, &d, &f)) {
const uint32_t l = d->get_file_length(d, f);
if (file_offset >= l)
return 0;
if (file_offset + count > l)
count = l - file_offset;
fmcpy(buffer, d, f, file_offset, count);
return count;
}
else
return 0;
}
uint32_t sc_file_write(uint32_t handle, uint32_t file_offset, uint32_t count, void *buffer) {
struct drive *d;
uint32_t f;
if (verify_file_handle(handle, &d, &f)) {
if (!d->is_writable(d, f))
return 0;
const uint32_t l = d->get_file_length(d, f);
if (file_offset >= l)
return 0;
if (file_offset + count > l)
count = l - file_offset;
mfcpy(d, f, file_offset, buffer, count);
return l;
}
else
return 0;
}
uint32_t sc_start_task(char *path, const char *pass, uint32_t io_task) {
struct drive *d;
const char *f;
map_path(path, &d, &f);
if (!d)
return 0;
switch_to_kernel_cr3();
uint32_t process_id = try_elf_run(d, vma_to_pma(active_task->page_directory, f), pass, io_task);
switch_to_task_cr3();
return process_id;
}
void *sc_allocate_ram(uint32_t pages) {
return pd_user_allocate_anywhere_writable(active_task->page_directory, pages);
}
enum mi_arg {
MI_KERNEL_MAX,
MI_KERNEL_LEFT,
MI_USER_MAX,
MI_USER_LEFT,
MI_TASK_LEFT
};
__attribute__ ((pure))
uint32_t sc_memory_info(enum mi_arg arg) {
switch (arg) {
case MI_KERNEL_MAX:
return max_kernel_pages;
case MI_KERNEL_LEFT:
return kernel_pages_left;
case MI_USER_MAX:
return max_user_pages;
case MI_USER_LEFT:
return user_pages_left;
case MI_TASK_LEFT:
PANIC("TODO: memory info task left");
default:
return -1;
}
}
void sc_wait_for_task(uint32_t handle) {
add_wait((struct wait){.mode = PROCESS_END, .task = tasks + handle - 1});
}
uint32_t sc_enumerate_dir(const char *path, struct directory_content_info *buffer, uint32_t max_entries) { //not static to ensure sysv abi
struct drive *d;
const char *f;
map_path(path, &d, &f);
return d ? d->enumerate_dir(d, f, buffer, max_entries) : 0;
}
uint32_t sc_count_of_dir(const char *path) {
struct drive *d;
const char *f;
map_path(path, &d, &f);
return d ? d->n_dir_entries(d, f) : 0;
}
void sc_get_next_window_action(struct window *w, struct window_action *action) {
*action = next_window_action(w);
}
void sc_wait_window_action() {
add_wait((struct wait){.mode = WINDOW_ACTION});
}
void sc_wait_ipc_sent(uint32_t task_handle) {
add_wait((struct wait){.mode = IPC_SENT, .task = tasks + task_handle - 1});
}
void sc_system_log(const char *sz) {
logf(LOG_USER, "[%s] %s", active_task->name, sz);
}
void sc_wait_any_ipc_sent() {
add_wait((struct wait){.mode = IPC_SENT_ANY});
}
void sc_wait_ipc_read(uint32_t handle) {
add_wait((struct wait){.mode = IPC_READ, .task = tasks + handle - 1});
}
//returns a uint32_t to ensure upper twenty-four bits of
// eax are set to zero - otherwise userland stuff break
__attribute__ ((pure))
uint32_t sc_is_task_running(uint32_t handle) {
return tasks[handle - 1].page_directory ? 1 : 0;
}
static const uint16_t days_into_four_years_per_month[] = {
0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335,
366, 366+31, 366+59, 366+90, 366+120, 366+151, 366+181, 366+212, 366+243, 366+273, 366+304, 366+334,
731, 731+31, 731+59, 731+90, 731+120, 731+151, 731+181, 731+212, 731+243, 731+273, 731+304, 731+334,
1096, 1096+31, 1096+59, 1096+90, 1096+120, 1096+151, 1096+181, 1096+212, 1096+243, 1096+273, 1096+304, 1096+334
};
//gregorian, assumes year is in 2001 to 2099
uint32_t sc_get_timestamp() {
const struct rtc_time time = get_rtc_time();
const uint32_t secs_into_month = time.seconds + time.minutes * 60 + time.hours * 3600 + (time.day_of_month - 1) * 86400;
const uint32_t days_to_month_into_four_years = days_into_four_years_per_month[time.month + (time.year % 4) * 12 - 1];
return secs_into_month + days_to_month_into_four_years * 86400 + (time.year / 4) * (365 * 4 + 1) * 86400;
}
void const *syscall_table[] = {
&sc_open_file,
&sc_close_file,
&sc_file_read,
&sc_file_get_size,
&sc_start_task,
&ipc_send,
&ipc_read,
&sc_allocate_ram,
&sc_memory_info,
&sc_wait_for_task,
&sc_enumerate_dir,
&sc_system_log,
&sc_count_of_dir,
&new_window,
&del_window,
&resize_window,
&reassign_pixel_buffer,
&push_window_paint,
&sc_get_next_window_action,
&sc_wait_window_action,
&sc_wait_ipc_sent,
&sc_wait_any_ipc_sent,
&find_unread_ipc,
&sc_wait_ipc_read,
&sc_is_task_running,
&sc_get_timestamp,
&sc_file_write,
&sc_file_set_size,
&window_wants_mouse_movements
};
//these aren't really void ()'s, but gcc complains if we take an address of a void, so we give it a type
typedef void isr_t();
extern isr_t syscall_isr;
extern isr_t quit_isr;
extern isr_t yield_isr;
extern isr_t kbd_isr;
extern isr_t mouse_isr;
extern isr_t udf_isr;
extern isr_t dfa_isr;
extern isr_t tsf_isr;
extern isr_t npf_isr;
extern isr_t ssf_isr;
extern isr_t gpf_isr;
extern isr_t pff_isr;
enum {
F_ID = 0x00200000,
F_VIP = 0x00100000,
F_VIF = 0x00080000,
F_AC = 0x00040000,
F_VM = 0x00020000,
F_RF = 0x00010000,
F_NT = 0x00004000,
F_OF = 0x00000800,
F_DF = 0x00000400,
F_IF = 0x00000200,
F_TF = 0x00000100,
F_SF = 0x00000080,
F_ZF = 0x00000040,
F_AF = 0x00000010,
F_PF = 0x00000004,
F_CF = 0x00000001,
F_IOPL_MASK = 0x00003000
};
__attribute__ ((noreturn))
void exception_halt(uint32_t eax, uint32_t ebx, uint32_t ecx,
uint32_t edx, uint32_t esi, uint32_t edi,
const char *id, uint32_t code,
uint32_t eip, uint32_t cs, uint32_t eflags,
uint32_t esp, uint32_t ss) {
if (code)
logf(LOG_ERROR, "Exception #%s (0x%h) in %s", id, code, active_task->name);
else
logf(LOG_ERROR, "Exception #%s in %s:", id, active_task->name);
logf(LOG_ERROR, " cs: 0x%hb ss: 0x%hb", cs, ss);
logf(LOG_ERROR, " eip: 0x%h esp: 0x%h", eip, esp);
logf(LOG_ERROR, " eax: 0x%h ebx: 0x%h", eax, ebx);
logf(LOG_ERROR, " ecx: 0x%h edx: 0x%h", ecx, edx);
logf(LOG_ERROR, " esi: 0x%h edi: 0x%h", esi, edi);
logf(LOG_ERROR, " eflags:%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
eflags & F_ID ? " ID" : "", eflags & F_VIP ? " VIP" : "",
eflags & F_VIF ? " VIF" : "", eflags & F_AC ? " AC" : "",
eflags & F_VM ? " VM" : "", eflags & F_RF ? " RF" : "",
eflags & F_NT ? " NT" : "", eflags & F_OF ? " OF" : "",
eflags & F_DF ? " DF" : "", eflags & F_IF ? " IF" : "",
eflags & F_TF ? " TF" : "", eflags & F_SF ? " SF" : "",
eflags & F_ZF ? " ZF" : "", eflags & F_AF ? " AF" : "",
eflags & F_PF ? " PF" : "", eflags & F_CF ? " CF" : "",
eflags & ~F_IOPL_MASK ? "" : " none");
logf(LOG_ERROR, " iopl: %d", (eflags >> 12) & 3);
logf(LOG_INFO, "Killing %s.", active_task->name);
quit_isr();
__builtin_unreachable();
}
#define MAX_STACK_EXPAND_PAGES 256
//returns true if stack was expanded
bool pf_check_stack(uint32_t cr2) {
if (cr2 >= active_task->stack_bottom - 0x1000 * MAX_STACK_EXPAND_PAGES) {
switch_to_kernel_cr3();
pd_user_allocate(active_task->page_directory, active_task->stack_bottom -= 4096, 1, true);
switch_to_task_cr3();
return true;
}
else {
logf(LOG_ERROR, "Illegal access of 0x%h", cr2);
return false;
}
}
static void register_int(uint8_t n, isr_t *isr, uint8_t dpl) {
idt[n].addr_low = (uint32_t)isr & 0xffff;
idt[n].addr_high = (uint32_t)isr >> 16;
idt[n].cs = 0x10;
idt[n].flags = IDT_PRESENT | (dpl << 5) | IDT_INT;
}
enum {
PIC_MCMD = 0x0020,
PIC_MDATA = 0x0021,
PIC_SCMD = 0x00a0,
PIC_SDATA = 0x00a1
};
enum {
PIC_RESET = 0x11
};
void init_idt() {
for (uint16_t i = 0; i < 256; ++i) {
idt[i].flags = 0;
idt[i].zero = 0;
}
register_int(0x30, &syscall_isr, 3);
register_int(0x38, &quit_isr, 3);
register_int(0x39, &yield_isr, 3);
register_int(0x21, &kbd_isr, 0);
register_int(0x2c, &mouse_isr, 0);
register_int(0x08, &udf_isr, 0);
register_int(0x08, &dfa_isr, 0);
register_int(0x0a, &tsf_isr, 0);
register_int(0x0b, &npf_isr, 0);
register_int(0x0c, &ssf_isr, 0);
register_int(0x0d, &gpf_isr, 0);
register_int(0x0e, &pff_isr, 0);
outb(PIC_MCMD, PIC_RESET);
outb(PIC_SCMD, PIC_RESET);
outb(PIC_MDATA, 0x20);
outb(PIC_SDATA, 0x28);
outb(PIC_MDATA, 0x04);
outb(PIC_SDATA, 0x02);
outb(PIC_MDATA, 0x01);
outb(PIC_SDATA, 0x01);
outb(PIC_MDATA, 0xf9);
outb(PIC_SDATA, 0xef);
asm volatile (
"lidt %0"
: : "m" (idtr) : "al");
}
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