[panic.serial] Add location to panic data

Updated kassert to be an actual function, and used the __builtin_*
functions for location data. Updated the panic handler protocol to
include sending location data as three more parameters. Updated the
serial panic handler to display that data along with the (optional)
message.

src/kernel/main.cpp

@@ -89,21 +89,6 @@ kernel_main(init::args *args)
 
     cpu_validate();
 
-    kassert(args->magic == init::args_magic,
-            "Bad kernel args magic number");
-
-    log::debug(logs::boot, "jsix init args are at: %016lx", args);
-    log::debug(logs::boot, "     Memory map is at: %016lx", args->mem_map);
-    log::debug(logs::boot, "ACPI root table is at: %016lx", args->acpi_table);
-    log::debug(logs::boot, "Runtime service is at: %016lx", args->runtime_services);
-    log::debug(logs::boot, "    Kernel PML4 is at: %016lx", args->pml4);
-
-    uint64_t cr0, cr4;
-    asm ("mov %%cr0, %0" : "=r"(cr0));
-    asm ("mov %%cr4, %0" : "=r"(cr4));
-    uint64_t efer = rdmsr(msr::ia32_efer);
-    log::debug(logs::boot, "Control regs: cr0:%lx cr4:%lx efer:%lx", cr0, cr4, efer);
-
     extern IDT &g_bsp_idt;
     extern TSS &g_bsp_tss;
     extern GDT &g_bsp_gdt;
@@ -120,6 +105,21 @@ kernel_main(init::args *args)
     cpu->rsp0 = idle_stack_end;
     cpu_early_init(cpu);
 
+    kassert(args->magic == init::args_magic,
+            "Bad kernel args magic number");
+
+    log::debug(logs::boot, "jsix init args are at: %016lx", args);
+    log::debug(logs::boot, "     Memory map is at: %016lx", args->mem_map);
+    log::debug(logs::boot, "ACPI root table is at: %016lx", args->acpi_table);
+    log::debug(logs::boot, "Runtime service is at: %016lx", args->runtime_services);
+    log::debug(logs::boot, "    Kernel PML4 is at: %016lx", args->pml4);
+
+    uint64_t cr0, cr4;
+    asm ("mov %%cr0, %0" : "=r"(cr0));
+    asm ("mov %%cr4, %0" : "=r"(cr4));
+    uint64_t efer = rdmsr(msr::ia32_efer);
+    log::debug(logs::boot, "Control regs: cr0:%lx cr4:%lx efer:%lx", cr0, cr4, efer);
+
     disable_legacy_pic();
 
     memory_initialize_pre_ctors(*args);

src/kernel/panic.serial/display.cpp

@@ -7,10 +7,27 @@
 namespace panic {
 
 void
-print_header(serial_port &out, const char *message)
+print_header(
+        serial_port &out,
+        const char *message,
+        const char *function,
+        const char *file,
+        uint64_t line)
 {
     out.write("\n\n\e[5;31m PANIC:\e[0;1;31m ");
-    out.write(message);
+    if (message) {
+        out.write(message);
+        out.write("\n ");
+    }
+    out.write(function);
+    out.write("  ");
+    out.write(file);
+    out.write(":");
+
+    char linestr[6];
+    snprintf(linestr, sizeof(linestr), "%d", line);
+    out.write(linestr);
+
     out.write("\n \e[0;31m===================================================================================\n");
 }
 

src/kernel/panic.serial/display.h

@@ -17,7 +17,13 @@ struct frame
     uintptr_t return_addr;
 };
 
-void print_header(serial_port &out, const char *message);
+void print_header(
+        serial_port &out,
+        const char *message,
+        const char *function,
+        const char *file,
+        uint64_t line);
+
 void print_callstack(serial_port &out, symbol_table &syms, frame const *fp);
 void print_cpu_state(serial_port &out, const cpu_state &regs);
 

src/kernel/panic.serial/entry.s

@@ -10,7 +10,7 @@ _panic_entry:
 	push 0 ; NMI doesn't push an error code
 	push 2 ; NMI is int 2
 	push_all
-	mov rdx, rsp
+	mov r9, rsp
 
 	mov rax, [rsp + REGS.rip]
 	push rax

src/kernel/panic.serial/main.cpp

@@ -6,8 +6,11 @@ struct cpu_state;
 
 extern "C"
 void panic_handler(
-        const char *message,
         const void *symbol_data,
+        const char *message,
+        const char *function,
+        const char *file,
+        uint64_t line,
         const cpu_state *regs)
 {
     panic::serial_port com1(panic::COM1);
@@ -16,7 +19,7 @@ void panic_handler(
     panic::frame const *fp = nullptr;
     asm ( "mov %%rbp, %0" : "=r" (fp) );
 
-    print_header(com1, message);
+    print_header(com1, message, function, file, line);
     print_callstack(com1, syms, fp);
     print_cpu_state(com1, *regs);