From d855c0a219a180497c2e50f9bc19bfce69b937a6 Mon Sep 17 00:00:00 2001
From: Ada Christine <adachristine18@gmail.com>
Date: Thu, 23 Jan 2025 00:24:57 +0000
Subject: it printfs with the efi interface

---
 service/Makefile                |  2 +-
 service/arch/x86_64/rtld_link.S |  2 ++
 service/config.h                |  6 ++++++
 service/kjarna.c                |  9 +++++++++
 service/main.c                  | 39 ++++++++++++++++++++++++++++++++++++---
 5 files changed, 54 insertions(+), 4 deletions(-)
 create mode 100644 service/config.h

(limited to 'service')

diff --git a/service/Makefile b/service/Makefile
index 0917b8c..09ff0be 100644
--- a/service/Makefile
+++ b/service/Makefile
@@ -17,7 +17,7 @@ LDSCRIPT := kjarna.ld
 
 CRT_OBJS := start.o rtld_link.o dynamic.o elf64.o kjarna.o
 LIB_OBJS := memcmp.o memcpy.o memmove.o memset.o string.o stdio.o \
-			printf.o
+			printf.o heap.o
 APP_OBJS := main.o
 
 OBJS := $(CRT_OBJS) $(LIB_OBJS) $(APP_OBJS) 
diff --git a/service/arch/x86_64/rtld_link.S b/service/arch/x86_64/rtld_link.S
index 7300a18..9f86030 100644
--- a/service/arch/x86_64/rtld_link.S
+++ b/service/arch/x86_64/rtld_link.S
@@ -2,6 +2,8 @@
 
 .extern kc_dynamic_link
 
+// TODO: investigate whether saving r9, r8, rcx and rdx is actually necessary here
+
 .hidden _rtld_link
 .global _rtld_link
 .type _rtld_link, @function
diff --git a/service/config.h b/service/config.h
new file mode 100644
index 0000000..18aa6f8
--- /dev/null
+++ b/service/config.h
@@ -0,0 +1,6 @@
+#pragma once
+
+#define KJARNA_REVISION 2 
+
+const char * const HAL_PATH = "/system/kernel.os";
+
diff --git a/service/kjarna.c b/service/kjarna.c
index 6b37d1e..1240c97 100644
--- a/service/kjarna.c
+++ b/service/kjarna.c
@@ -8,6 +8,15 @@ int kjarna_entry(struct kjarna_entry_params *params)
 {
 	entry_params = params;
 
+	__asm__ ("leaq kc_image_base(%%rip), %%rax" ::: "rax");
+
+	bool wait = true;
+
+	while(wait)
+	{
+		__asm__ volatile("hlt");
+	}
+
 	return main(params->argc, params->argv);
 }
 
diff --git a/service/main.c b/service/main.c
index 12a5522..c022b87 100644
--- a/service/main.c
+++ b/service/main.c
@@ -1,7 +1,42 @@
 #include <unistd.h>
 #include <stdio.h>
+#include <fcntl.h>
+#include <stdlib.h>
 
-#define KJARNA_REVISION 1
+#include "config.h"
+#include <lib/elf.h>
+
+/*
+static int open_kernel(void)
+{
+	int kernel_fd = open(HAL_PATH, 0, 0);
+
+	printf("kernel path: %s\n", HAL_PATH);
+
+	if (kernel_fd < 0)
+	{
+		printf("error: could not open kernel core\n");
+		return -1;
+	}
+
+	Elf64_Ehdr ehdr;
+
+	if (!elf64_validate_fd(kernel_fd, ET_DYN, EM_X86_64))
+	{
+		printf("error: could not validate elf header\n");
+		close(kernel_fd);
+		return -1;
+	}
+
+	printf("kernel: elf x86_64 dynamic object found\r\n");
+
+	ssize_t kernel_size = elf64_size_fd(fd);
+
+	printf("kernel image size %zd\n", kernel_size);
+
+	return kernel_fd;
+}
+*/
 
 int main(int argc, char **argv)
 {
@@ -10,8 +45,6 @@ int main(int argc, char **argv)
 
 	printf("kjarna %d\n", KJARNA_REVISION);
 
-	while (1);
-
 	return 0;
 }
 
-- 
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