stuff and things

5 files changed, 133 insertions, 18 deletions

diff --git a/sys/kern/entry.S b/sys/kern/entry.S
index 5ad0490..fccd80f 100644
--- a/sys/kern/entry.S
+++ b/sys/kern/entry.S
@@ -11,9 +11,10 @@ _start:
         la         gp, __global_pointer$
         .option pop
 
-        la         sp, __stack_start
+        addi       t0, a0, 1
         li         t1, PAGE_SIZE 
-        mul        t1, t1, a0
+        la         sp, __stack_start
+        mul        t1, t1, t0
         add        sp, sp, t1
 
         li         a2, 1
@@ -37,3 +38,6 @@ _spin:
 
 .section ".data"
 _boot_hart: .word 0
+.section ".rodata"
+.globl HEAP_START
+HEAP_START: .dword __heap_start
diff --git a/sys/kern/init.c b/sys/kern/init.c
index a49c304..18feaa3 100644
--- a/sys/kern/init.c
+++ b/sys/kern/init.c
@@ -1,11 +1,20 @@
 #include <fdt.h>
-#include <kernel_earlyprintf.h>
+#include <printf.h>
+#include <stdint.h>
+#include <mm/kalloc.h>
+
+extern uint64_t HEAP_START;
 
 void 
 init(unsigned long hartid, struct fdt_header *fdt)
 {
-	kernel_earlyputs("booting...\n");
+	printf("booting from hart #%d\n", hartid);
 	if (fdt_uint32(fdt->magic) == FDT_HEADER_MAGIC) 
-		kernel_earlyputs("found flattened device tree!\n");
-
+		printf("found flattened device tree at %p!\n", (uint64_t)fdt);
+        
+        printf("setting up the heap at %p\n", HEAP_START);
+        kalloc_init();
+        printf("done!\n");
+        printf("printing free pages:\n");
+        walkfree();
 }
diff --git a/sys/kern/kernel_earlyprintf.c b/sys/kern/kernel_earlyprintf.c
deleted file mode 100644
index e6c85c4..0000000
--- a/sys/kern/kernel_earlyprintf.c
+++ /dev/null
@@ -1,11 +0,0 @@
-#include <kernel_earlyprintf.h>
-#include <sbi.h>
-
-int
-kernel_earlyputs(const char *str)
-{
-	do {
-		sbi_console_putchar(*str);
-	} while (*(str++) != '\0');
-}
-
diff --git a/sys/kern/mm/kalloc.c b/sys/kern/mm/kalloc.c
index b17d432..f354648 100644
--- a/sys/kern/mm/kalloc.c
+++ b/sys/kern/mm/kalloc.c
@@ -1,7 +1,11 @@
 #include <stddef.h>
+#include <stdint.h>
 #include <string.h>
+#include <printf.h>
 #include <mm/kalloc.h>
 
+extern uint64_t HEAP_START; 
+
 typedef struct freenode {
 	struct freenode *next;
 } freenode_t;
@@ -31,10 +35,34 @@ kzalloc(void)
 void
 kfree(void *p)
 {
-	if (p == NULL || (unsigned long)p % PAGE_SIZE)
+	if (p == NULL)
 		return;
 
 	freenode_t *tmp = head;
 	head = p;
 	head->next = tmp;
 }
+
+void
+kalloc_init(void)
+{
+        printf("1\n");
+        freenode_t *p = (freenode_t*)HEAP_START;
+        for (;(unsigned long)p + PAGE_SIZE <= (HEAP_START + 0x100000); p += PAGE_SIZE) {
+                printf("freeing page at %p", p);
+                kfree(p);
+        }
+}
+
+void 
+walkfree(void)
+{
+        freenode_t *node = head;
+        int nfree = 0;
+        while (node) {
+                printf("freenode at %p\n", node);
+                node = node->next;
+                nfree++;
+        }
+        printf("found and printed %d free pages!\n", nfree);
+}
diff --git a/sys/kern/printf.c b/sys/kern/printf.c
new file mode 100644
index 0000000..dfd0657
--- /dev/null
+++ b/sys/kern/printf.c
@@ -0,0 +1,85 @@
+#include <printf.h>
+#include <stdint.h>
+#include <sbi.h>
+#include <stdarg.h>
+
+static char digits[] = "0123456789abcdef";
+
+int
+puts(const char *str)
+{
+	do {
+		sbi_console_putchar(*str);
+	} while (*(str++) != '\0');
+}
+
+#define PUTCHAR(c)      sbi_console_putchar(c)
+
+static void
+printint(int xx, int base, int sign)
+{
+        char buf[16];
+        int i;
+        unsigned int x;
+
+        if (sign && (sign = xx < 0))
+                x = -xx;
+        else 
+                x = xx; 
+
+        i = 0;
+        do {
+                buf[i++] = digits[x % base];
+        } while ((x /= base) != 0);
+
+        if (sign)
+                buf[i++] = '-';
+        while (--i >= 0)
+                PUTCHAR(buf[i]);
+
+}
+
+static void 
+printptr(uint64_t x)
+{
+        int i;
+        puts("0x");
+        for (i = 0; i < (sizeof(uint64_t) * 2); i++, x <<= 4)
+                PUTCHAR(digits[x >> (sizeof(int64_t) * 8 - 4)]);
+}
+
+void
+printf(const char *fmt, ...) 
+{
+        va_list ap;
+        int i, c;
+        char *s;
+
+        va_start(ap, fmt);
+
+        for (i = 0; (c = fmt[i] & 0xff) != 0; i++) {
+                if (c != '%') {
+                        PUTCHAR(c);
+                        continue;
+                }
+                c = fmt[++i] & 0xff;
+                if (!c) 
+                        break;
+
+                switch (c) {
+                        case 'd':
+                        case 'i':
+                                printint(va_arg(ap, int), 10, 1);
+                                break;
+                        case 'x':
+                                printint(va_arg(ap, int), 16, 1);
+                                break;
+                        case 'p':
+                                printptr(va_arg(ap, uint64_t));
+                                break;
+                        case '%':
+                                PUTCHAR('%');
+                                break;
+                }
+        }
+}