[new uImage] Provide ability to restrict region used for boot images

Allow the user to set 'bootm_low' and 'bootm_size' env vars as a way
to restrict what memory range is used for bootm.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Marian Balakowicz <m8@semihalf.com>

common/cmd_bootm.c

@@ -124,6 +124,7 @@ int do_bootm (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 	ulong		os_data, os_len;
 	ulong		image_start, image_end;
 	ulong		load_start, load_end;
+	ulong		mem_start, mem_size;
 
 	struct lmb lmb;
 
@@ -134,11 +135,10 @@ int do_bootm (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 
 	lmb_init(&lmb);
 
-#ifdef CFG_SDRAM_BASE
-	lmb_add(&lmb, CFG_SDRAM_BASE, gd->bd->bi_memsize);
-#else
-	lmb_add(&lmb, 0, gd->bd->bi_memsize);
-#endif
+	mem_start = getenv_bootm_low();
+	mem_size = getenv_bootm_size();
+
+	lmb_add(&lmb, mem_start, mem_size);
 
 	board_lmb_reserve(&lmb);
 

common/image.c

@@ -132,6 +132,32 @@ int getenv_autostart (void)
 	return (s && (*s == 'n')) ? 0 : 1;
 }
 
+ulong getenv_bootm_low(void)
+{
+	char *s = getenv ("bootm_low");
+	if (s) {
+		ulong tmp = simple_strtoul (s, NULL, 16);
+		return tmp;
+	}
+
+#ifdef CFG_SDRAM_BASE
+	return CFG_SDRAM_BASE;
+#else
+	return 0;
+#endif
+}
+
+ulong getenv_bootm_size(void)
+{
+	char *s = getenv ("bootm_size");
+	if (s) {
+		ulong tmp = simple_strtoul (s, NULL, 16);
+		return tmp;
+	}
+
+	return gd->bd->bi_memsize;
+}
+
 void memmove_wd (void *to, void *from, size_t len, ulong chunksz)
 {
 #if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)

include/image.h

@@ -316,6 +316,8 @@ int image_check_dcrc (image_header_t *hdr);
 int image_check_dcrc_wd (image_header_t *hdr, ulong chunksize);
 int getenv_verify (void);
 int getenv_autostart (void);
+ulong getenv_bootm_low(void);
+ulong getenv_bootm_size(void);
 void memmove_wd (void *to, void *from, size_t len, ulong chunksz);
 #endif
 

lib_m68k/bootm.c

@@ -57,12 +57,14 @@ void do_bootm_linux(cmd_tbl_t * cmdtp, int flag,
 	int ret;
 
 	ulong cmd_start, cmd_end;
-	ulong bootmap_base = 0;
+	ulong bootmap_base;
 	bd_t  *kbd;
 	ulong ep = 0;
 	void  (*kernel) (bd_t *, ulong, ulong, ulong, ulong);
 	struct lmb *lmb = images->lmb;
 
+	bootmap_base = getenv_bootm_low();
+
 	/*
 	 * Booting a (Linux) kernel image
 	 *

lib_ppc/bootm.c

@@ -59,6 +59,10 @@ extern ulong get_effective_memsize(void);
 static ulong get_sp (void);
 static void set_clocks_in_mhz (bd_t *kbd);
 
+#ifndef CFG_LINUX_LOWMEM_MAX_SIZE
+#define CFG_LINUX_LOWMEM_MAX_SIZE	(768*1024*1024)
+#endif
+
 void  __attribute__((noinline))
 do_bootm_linux(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[],
 		bootm_headers_t *images)
@@ -67,6 +71,7 @@ do_bootm_linux(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[],
 
 	ulong	initrd_start, initrd_end;
 	ulong	rd_data_start, rd_data_end, rd_len;
+	ulong	size;
 
 	ulong	cmd_start, cmd_end, bootmap_base;
 	bd_t	*kbd;
@@ -80,7 +85,24 @@ do_bootm_linux(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[],
 	char	*of_flat_tree = NULL;
 #endif
 
-	bootmap_base = 0;
+	bootmap_base = getenv_bootm_low();
+	size = getenv_bootm_size();
+
+#ifdef DEBUG
+	if (((u64)bootmap_base + size) > (CFG_SDRAM_BASE + (u64)gd->ram_size))
+		puts("WARNING: bootm_low + bootm_size exceed total memory\n");
+	if ((bootmap_base + size) > get_effective_memsize())
+		puts("WARNING: bootm_low + bootm_size exceed eff. memory\n");
+#endif
+
+	size = min(size, get_effective_memsize());
+	size = min(size, CFG_LINUX_LOWMEM_MAX_SIZE);
+
+	if (size < getenv_bootm_size()) {
+		ulong base = bootmap_base + size;
+		printf("WARNING: adjusting available memory to %x\n", size);
+		lmb_reserve(lmb, base, getenv_bootm_size() - size);
+	}
 
 	/*
 	 * Booting a (Linux) kernel image
@@ -92,7 +114,7 @@ do_bootm_linux(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[],
 	 * pointer.
 	 */
 	sp = get_sp();
-	debug ("## Current stack ends at 0x%08lx ", sp);
+	debug ("## Current stack ends at 0x%08lx\n", sp);
 
 	/* adjust sp by 1K to be safe */
 	sp -= 1024;