Some slight robustness improvements and obo errors

5 files changed, 55 insertions, 23 deletions

diff --git a/TODO.txt b/TODO.txt
index 1d84441..012fba9 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -11,3 +11,4 @@
 + Mark fdt, reserved mem, kernel, init and initrd in vmem. Remember to remove
 init from vmem when jumping to vmem
 + Figure out best way to tell the init how large out kernel is
++ Make code more robust, error checking etc
diff --git a/arch/riscv/init/init.c b/arch/riscv/init/init.c
index c389e3b..5612d0b 100644
--- a/arch/riscv/init/init.c
+++ b/arch/riscv/init/init.c
@@ -31,26 +31,40 @@ static struct cell_info get_cellinfo(void *fdt, int offset)
 
 }
 
-static struct pmem_layout get_memlayout(void *fdt)
+/* How "reg" is interpreted depends on the parent node */
+static struct cell_info get_reginfo(void *fdt, const char *path)
 {
-	struct cell_info ci = get_cellinfo(fdt, 0);
+	const char *i = strrchr(path, '/');
+	if(!i)
+		return (struct cell_info){0, 0};
+
+	size_t baselen = i - path;
+	if(i == 0)
+		/* root node */
+		baselen = 1;
+
+	return get_cellinfo(fdt, fdt_path_offset_namelen(fdt, path, baselen));
+}
 
+static struct pmem_layout get_memlayout(void *fdt)
+{
+	struct cell_info ci = get_reginfo(fdt, "/memory");
 	int mem_offset = fdt_path_offset(fdt, "/memory");
 	uint8_t *mem_reg =
 		(uint8_t *) fdt_getprop(fdt, mem_offset, "reg", NULL);
 
 	/* if riscv128 comes around we will probably see addr_cells == 4, but
 	 * I'm not too concerned about it at the moment */
-	pm_t base = fdt_load_int_ptr(pm_t, ci.addr_cells, mem_reg);
+	pm_t base = (pm_t)fdt_load_int_ptr(ci.addr_cells, mem_reg);
 
 	if(ci.addr_cells == 2)
 		mem_reg += sizeof(fdt64_t);
 	else
 		mem_reg += sizeof(fdt32_t);
 
-	pm_t top = fdt_load_int_ptr(pm_t, ci.size_cells, mem_reg) + base;
-	struct pmem_layout ret = { base, top };
-	return ret;
+	/* -1 because base is a legitimate memory address */
+	pm_t top = (pm_t)fdt_load_int_ptr(ci.size_cells, mem_reg) + base - 1;
+	return (struct pmem_layout){base, top};
 }
 
 #ifdef DEBUG
@@ -80,11 +94,11 @@ static void init_debug(void *fdt)
 	enum serial_dev_t dev = serial_dev_enum(dev_name);
 
 	/* get serial device address */
-	struct cell_info ci = get_cellinfo(fdt, stdout_offset);
+	struct cell_info ci = get_reginfo(fdt, stdout);
 	void *reg_ptr = (void *)fdt_getprop(fdt, stdout_offset, "reg", NULL);
 
 	void *uart_ptr = 0;
-	uart_ptr = (void *)fdt_load_int_ptr(pm_t, ci.addr_cells, reg_ptr);
+	uart_ptr = (void *)(pm_t)fdt_load_int_ptr(ci.addr_cells, reg_ptr);
 
 	dbg_init(uart_ptr, dev);
 }
@@ -110,7 +124,7 @@ static pm_t get_initrdtop(void *fdt)
 	void *initrd_end_ptr = (void *)fdt_getprop(fdt, chosen_offset,
 			"linux,initrd-end", NULL);
 
-	return fdt_load_int_ptr(pm_t, ci.addr_cells, initrd_end_ptr);
+	return (pm_t)fdt_load_int_ptr(ci.addr_cells, initrd_end_ptr);
 }
 
 static pm_t get_fdttop(void *fdt)
@@ -132,7 +146,9 @@ static void setup_pmem(void *fdt)
 	dbg("kernel_top:\t%#lx\n", kernel_top);
 	dbg("fdt_top:\t%#lx\n", fdt_top);
 
-	populate_pmap(pmem.base, pmem.top - pmem.base, top + 1);
+	/* riscv handles two byte boundaries better than one byte, so align
+	 * upwards */
+	populate_pmap(pmem.base, pmem.top - pmem.base, align_up(top + 1, 2));
 
 	/* TODO: mark used pages */
 }
diff --git a/common/string.c b/common/string.c
index af9c54a..0870b78 100644
--- a/common/string.c
+++ b/common/string.c
@@ -93,12 +93,11 @@ __weak int strncmp(const char *str1, const char *str2, size_t num)
 __weak char *strchr(const char *str, int chr)
 {
 	const char *s1 = str;
-	size_t num = strlen(s1);
+	ssize_t num = strlen(s1);
 
 	while (num-- && *(s1--) != chr) ;
 
-	num++;
-	if (!num)
+	if (num < 0)
 		return 0;
 
 	return (char *)(s1 + 1);
@@ -162,16 +161,15 @@ __weak char *strstr(const char *str1, const char *str2)
 #undef strrchr
 __weak char *strrchr(const char *str, int chr)
 {
-	size_t num = strlen(str);
-	const char *s1 = str + num;
+	ssize_t num = strlen(str);
+	const char *s1 = (str + num) - 1;
 
 	while (num-- && *(s1--) != chr) ;
 
-	num++;
-	if (!num)
+	if (num < 0)
 		return 0;
 
-	return (char *)s1;
+	return (char *)(s1 + 1);
 }
 
 #undef strpbrk
@@ -262,12 +260,12 @@ __weak void *memset(void *ptr, int value, size_t num)
 __weak void *memchr(const void *ptr, int val, size_t num)
 {
 	const char *p1 = (char *)ptr;
+	ssize_t n = num;
 	char c = (char)val;
 
-	while (num-- && *(p1++) != c) ;
+	while (n-- && *(p1++) != c) ;
 
-	num++;
-	if (!num)
+	if (n < 0)
 		return 0;
 
 	return (void *)(p1 - 1);
diff --git a/include/apos/utils.h b/include/apos/utils.h
index 45e7194..3855a37 100644
--- a/include/apos/utils.h
+++ b/include/apos/utils.h
@@ -11,4 +11,21 @@
 #define MIN4(a, b, c, d) (MIN3(a, b, c) <= MIN3(b, c, d) ? MIN3(a, b, c) : MIN3(b, c, d))
 /* etc... */
 
+#include <apos/types.h>
+
+static inline size_t align_up(size_t val, size_t a)
+{
+	size_t rem = val % a;
+
+	if (rem == 0)
+		return val;
+
+	return val + a - rem;
+}
+
+static inline size_t align_down(size_t val, size_t a)
+{
+	return val - (val % a);
+}
+
 #endif /* APOS_UTILS_H */
diff --git a/include/libfdt.h b/include/libfdt.h
index 7425aef..406b6d7 100644
--- a/include/libfdt.h
+++ b/include/libfdt.h
@@ -9,7 +9,7 @@ void __dbg_fdt(void *fdt, int node_offset, int depth);
 #define dbg_fdt(...)
 #endif
 
-#define fdt_load_int_ptr(t, c, p)\
-	((c) == 2 ? (t)fdt64_to_cpu(*(fdt64_t *)(p)) : (t)fdt32_to_cpu(*(fdt32_t *)(p)))
+#define fdt_load_int_ptr(c, p)\
+	((c) == 2 ? fdt64_to_cpu(*(fdt64_t *)(p)) : fdt32_to_cpu(*(fdt32_t *)(p)))
 
 #endif