arm: mxs: Adjust the load address of U-Boot and SPL for HAB

When using HAB, there are additional special requirements on the placement of U-Boot and the U-Boot SPL in memory. To fullfill these, this patch moves the U-Boot binary a little further from the begining of the DRAM, so the HAB CST and IVT can be placed in front of the U-Boot binary. This is necessary, since both the U-Boot and the IVT must be contained in single CST signature. To make things worse, the IVT must be concatenated with one more entry at it's end, that is the length of the entire CST signature, IVT and U-Boot binary in memory. By placing the blocks in this order -- CST, IVT, U-Boot, we can easily align them all and then produce the length field as needed.

As for the SPL, on i.MX23/i.MX28, the SPL size is limited to 32 KiB, thus we place the IVT at 0x8000 offset, CST right past IVT and claim the size is correct. The HAB library accepts this setup.

Finally, to make sure the vectoring in SPL still works even after moving the SPL from 0x0 to 0x1000, we add a small function which copies the vectoring code and tables to 0x0. This is fine, since the vectoring code is position independent.

---
 arch/arm/cpu/arm926ejs/mxs/mxsimage.mx23.cfg |  8 ++++----
 arch/arm/cpu/arm926ejs/mxs/mxsimage.mx28.cfg |  8 ++++----
 arch/arm/cpu/arm926ejs/mxs/spl_boot.c        | 15 +++++++++++++++
 arch/arm/cpu/arm926ejs/mxs/u-boot-spl.lds    |  2 +-
 include/configs/mxs.h                        | 10 +++++++++-
 5 files changed, 33 insertions(+), 10 deletions(-)

index c9cf4b3..70abfbc 100644
@@ -1,6 +1,6 @@
 SECTION 0x0 BOOTABLE
  TAG LAST
- LOAD     0x0        OBJTREE/spl/u-boot-spl.bin
- CALL     0x14       0x0
- LOAD     0x40000100 OBJTREE/u-boot.bin
- CALL     0x40000100 0x0
+ LOAD     0x1000     OBJTREE/spl/u-boot-spl.bin
+ CALL     0x1000     0x0
+ LOAD     0x40002000 OBJTREE/u-boot.bin
+ CALL     0x40002000 0x0

index 676f5c8..e98c97b 100644
@@ -1,8 +1,8 @@
 SECTION 0x0 BOOTABLE
  TAG LAST
- LOAD     0x0        OBJTREE/spl/u-boot-spl.bin
- LOAD IVT 0x8000     0x14
+ LOAD     0x1000     OBJTREE/spl/u-boot-spl.bin
+ LOAD IVT 0x8000     0x1000
  CALL HAB 0x8000     0x0
- LOAD     0x40000100 OBJTREE/u-boot.bin
- LOAD IVT 0x8000     0x40000100
+ LOAD     0x40002000 OBJTREE/u-boot.bin
+ LOAD IVT 0x8000     0x40002000
  CALL HAB 0x8000     0x0

index 68c30af..38109c5 100644
@@ -102,6 +102,18 @@ static uint8_t mxs_get_bootmode_index(void)
 	return i;
 }
 
+static void mxs_spl_fixup_vectors(void)
+{
+	/*
+	 * Copy our vector table to 0x0, since due to HAB, we cannot
+	 * be loaded to 0x0. We want to have working vectoring though,
+	 * thus this fixup. Our vectoring table is PIC, so copying is
+	 * fine.
+	 */
+	extern uint32_t _start;
+	memcpy(0x0, &_start, 0x60);
+}
+
 void mxs_common_spl_init(const uint32_t arg, const uint32_t *resptr,
 			 const iomux_cfg_t *iomux_setup,
 			 const unsigned int iomux_size)

@@ -110,7 +122,10 @@ void mxs_common_spl_init(const uint32_t arg, const uint32_t *resptr,
 		((CONFIG_SYS_TEXT_BASE - sizeof(struct mxs_spl_data)) & ~0xf);
 	uint8_t bootmode = mxs_get_bootmode_index();
 
+	mxs_spl_fixup_vectors();
+
 	mxs_iomux_setup_multiple_pads(iomux_setup, iomux_size);
+
 	mxs_power_init();
 
 	mxs_mem_init();

index d0b482d..f4bf8ac 100644
@@ -16,7 +16,7 @@ OUTPUT_ARCH(arm)
 ENTRY(_start)
 SECTIONS
 {
-	. = 0x00000000;
+	. = CONFIG_SPL_TEXT_BASE;
 
 	. = ALIGN(4);
 	.text	:

index 55ecef9..a9f4d89 100644
@@ -80,8 +80,16 @@
  * We need to sacrifice first 4 bytes of RAM here to avoid triggering some
  * strange BUG in ROM corrupting first 4 bytes of RAM when loading U-Boot
  * binary. In case there was more of this mess, 0x100 bytes are skipped.
+ *
+ * In case of a HAB boot, we cannot for some weird reason use the first 4KiB
+ * of DRAM when loading. Moreover, we use the first 4 KiB for IVT and CST
+ * blocks, thus U-Boot starts at offset +8 KiB of DRAM start.
+ *
+ * As for the SPL, we must avoid the first 4 KiB as well, but we load the
+ * IVT and CST to 0x8000, so we don't need to waste the subsequent 4 KiB.
  */
-#define CONFIG_SYS_TEXT_BASE		0x40000100
+#define CONFIG_SYS_TEXT_BASE		0x40002000
+#define CONFIG_SPL_TEXT_BASE		0x00001000
 
 /* U-Boot general configuration */
 #define CONFIG_SYS_LONGHELP

1.8.5.2

This patch adds the groundwork for generating signed BootStream, which can be used by the HAB library in i.MX28. We are adding a new target, u-boot-signed.sb , since the process for generating regular non-signed BootStream is much easier. Moreover, the signed bootstream depends on external _proprietary_ _binary-only_ tool from Freescale called 'cst', which is available only under NDA.

To make things even uglier, the CST or HAB mandates a kind-of circular dependency. The problem is, unlike the regular IVT, which is generated by mxsimage, the IVT for signed boot must be generated by hand here due to special demands of the CST. The U-Boot binary (or SPL binary) and IVT are then signed by the CST as a one block. But here is the problem. The size of the entire image (U-Boot, IVT, CST blocks) must be appended at the end of IVT. But the size of the entire image is not known until the CST has finished signing the U-Boot and IVT. We solve this by expecting the CST block to be always 3904B (which it is in case two files, U-Boot and the hand-made IVT, are signed in the CST block).

---
 Makefile                                       |  2 +
 arch/arm/cpu/arm926ejs/mxs/Makefile            | 77 ++++++++++++++++++++++++++
 arch/arm/cpu/arm926ejs/mxs/mxsimage-signed.cfg | 10 ++++
 3 files changed, 89 insertions(+)
 create mode 100644 arch/arm/cpu/arm926ejs/mxs/mxsimage-signed.cfg

index ecac292..01d4011 100644
@@ -856,6 +856,8 @@ OBJCOPYFLAGS_u-boot.ais = -I binary -O binary --pad-to=$(CONFIG_SPL_MAX_SIZE)
 u-boot.ais: spl/u-boot-spl.ais u-boot.img FORCE
 	$(call if_changed,pad_cat)
 
+u-boot-signed.sb: u-boot.bin spl/u-boot-spl.bin
+	$(Q)$(MAKE) $(build)=arch/arm/cpu/arm926ejs/mxs $(objtree)/u-boot-signed.sb
 u-boot.sb: u-boot.bin spl/u-boot-spl.bin
 	$(Q)$(MAKE) $(build)=arch/arm/cpu/arm926ejs/mxs $(objtree)/u-boot.sb
 

new file mode 100644
index 0000000..903b6b2
@@ -0,0 +1,10 @@
+SECTION 0x0 BOOTABLE
+ TAG LAST
+ LOAD     0x1000     OBJTREE/spl/u-boot-spl.bin
+ LOAD     0x8000     OBJTREE/spl/u-boot-spl.ivt
+ LOAD     0x8040     OBJTREE/spl/u-boot-spl.sig
+ CALL HAB 0x8000     0x0
+ LOAD     0x40002000 OBJTREE/u-boot.bin
+ LOAD     0x40001000 OBJTREE/u-boot.ivt
+ LOAD     0x40001040 OBJTREE/u-boot.sig
+ CALL HAB 0x40001000 0x0

1.8.5.2

Applied to u-boot-imx, thanks !

Best regards,
Stefano Babic

=====================================================================
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de
=====================================================================

Applied to u-boot-imx, thanks !

Best regards,
Stefano Babic

=====================================================================
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de
=====================================================================