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#include "arch/user/main.hpp"
#include "arch/context_switching/syscall/main.hpp"
// TODO: Disallow this import
#include "arch/video/vga/text.hpp"
namespace teachos::arch::user
{
[[gnu::section(".user_text")]]
auto main() -> void
{
// TODO: Remove or replace this wall of text
// RFLAGS is saved into R11, RIP of the next instruction into RCX
// Required for SYSRETURN to know where to return too.
// Additional state needs to be saved by calling convention:
// Syscall Number: RAX, Return Value: RAX (0 indicating no error, and -1 indicating an error, use as a boolean)
// Argument in this order (max 6. no argument on stack): RDI, RSI, RDX, R10, R8, R9
// Not used registers: RBX, RSP, R12, R13, R14
// Actual Source: https://man7.org/linux/man-pages/man2/syscall.2.html More cleare documentation:
// https://sys.readthedocs.io/en/latest/doc/05_calling_system_calls.html
char constexpr syscall_message[] = "Successfully entered user mode and wrote to VGA buffer via syscall!";
auto const error = context_switching::syscall::syscall(context_switching::syscall::type::WRITE,
{reinterpret_cast<uint64_t>(&syscall_message)});
if (!error)
{
video::vga::text::write("Successfully made a SYSCALL and returned with SYSRETQ!",
video::vga::text::common_attributes::green_on_black);
}
}
} // namespace teachos::arch::user
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