S5L8702: Reallocate the bootloader without dependency on _dfuloadaddr

Also adds support for S5L8720 initialization.

This currently changes only the bootloader code for ipod6g. Tested on target.

This is a part of the large iPod Nano 3G and iPod Nano 4G support patch.

Credit: Cástor Muñoz <cmvidal@gmail.com>
Change-Id: Ib4b5f12b701058940c1c5bd686d8ac346ae14e12

1 files changed, 54 insertions, 10 deletions

diff --git a/firmware/target/arm/s5l8702/crt0.S b/firmware/target/arm/s5l8702/crt0.S
index 915c3f680b..a3ffcdff53 100644
--- a/firmware/target/arm/s5l8702/crt0.S
+++ b/firmware/target/arm/s5l8702/crt0.S
@@ -38,31 +38,56 @@ start:
     ldr pc, =fiq_handler
     .ltorg
 _newstart:
-#if !defined(BOOTLOADER)
-    ldr pc, =newstart2 // we do not want to execute from 0x0 as iram will be mapped there
+#ifndef BOOTLOADER
+    /* we do not want to execute from 0x0 as iram will be mapped there */
+    ldr pc, =newstart2
     .section .init.text,"ax",%progbits
 newstart2:
 #endif
     msr     cpsr_c, #0xd3 /* enter supervisor mode, disable IRQ/FIQ */
 
 #ifdef BOOTLOADER
-    /* Relocate ourself to IRAM1 - we have been loaded to IRAM0 */
-    ldr     r0, =_dfuloadaddr
-    ldr     r1, =_movestart
-    ldr     r2, =_moveend
+    /* Actually we are reallocating from load address IRAM0:0000 or
+     * IRAM1:0000 to exec address IRAM1:0800.
+     * Note that vector section is also reallocated to IRAM0:0000.
+     */
+    /* Reallocate from IRAM0:0000 or IRAM1:0000 to IRAM1:0800 */
+    /* _movestart and _moveend must be already aligned to 32-byte */
+
+_rtpc:
+    sub     r11, pc, #8         /* subtract 8 for pipeline */
+    sub     r11, #_rtpc-start   /* _src_start = runtime start: address */
+
+    /* [start .. start+_movelen] -> [_movestart .. _moveend] */
+    ldr     r1, =_moveend
+    ldr     r2, =_movestart
+    sub     r3, r1, r2          /* _movelen = _moveend - _movestart */
+    add     r0, r11, r3         /* _src_end = _src_start + _movelen */
 1:
+    ldmdb   r0!, {r3-r10}
+    stmdb   r1!, {r3-r10}
+    cmp     r2, r1
+    blt     1b
+
+    /* copy vector section to start of IRAM0 (it will be mapped to 0x0) */
+    /* [start .. _newstart] -> [IRAM0_START .. IRAM0_START+vect_len] */
+    mov     r0, r11                         // src start
+    ldr     r1, =IRAM0_ORIG                 // dst start
+    add     r2, r1, #_newstart-start        // dst end
+2:
     ldmia   r0!, {r3-r10}
     stmia   r1!, {r3-r10}
     cmp     r1, r2
-    blt     1b
+    blt     2b
 
     ldr     pc, =start_loc    /* jump to the relocated start_loc: */
 
     .section .init.text,"ax",%progbits
     .global  start_loc
 start_loc:
-#endif
+#endif /* BOOTLOADER */
 
+#if defined(IPOD_6G) || defined(IPOD_NANO3G)
     mrc     p15, 0, r0, c1, c0, 0
     bic     r0, r0, #0x1000
     bic     r0, r0, #0x5
@@ -75,7 +100,26 @@ start_loc:
     mcr     p15, 0, r0, c7, c10, 4  /* drain write buffer */
     mcr     p15, 0, r0, c7, c5, 0   /* invalidate icache */
 
-    /* reset VIC controller */
+#elif defined(IPOD_NANO4G)
+    mrc     p15, 0, r0, c1, c0, 0
+    bic     r0, r0, #0x1000
+    bic     r0, r0, #0x5
+    mcr     p15, 0, r0, c1, c0, 0   /* disable caches and protection unit */
+
+    mov     r0, #0
+    mcr     p15, 0, r0, c7, c14, 0  /* clean & invalidate dcache */
+    mcr     p15, 0, r0, c7, c10, 4  /* drain write buffer */
+    mcr     p15, 0, r0, c7, c5, 0   /* invalidate icache */
+    mcr     p15, 0, r0, c7, c5, 4   /* flush prefetch buffer */
+
+    mcr     p15, 0, r0, c8, c7, 0   /* invalidate all unlocked entries in TLB */
+    mcr     p15, 0, r0, c13, c0, 0  /* disable context id register */
+    /* XXX: arm1176jaf page 249/972 */
+    // TODO: put it in mmu-armv6.S
+    // mcr     p15, 0, r0, c2, c0, 2   /* write translation table control register (set backwards compatiblity) */
+#endif
+
+    /* reset VIC controller */              // TODO: this could go to system_init()
     ldr     r1, =0x38e00000
     add     r2, r1, #0x00001000
     add     r3, r1, #0x00002000
@@ -86,7 +130,7 @@ start_loc:
     str     r4, [r2,#0xf00]
     str     r4, [r3,#0x08]
     str     r4, [r3,#0x0c]
-    str     r0, [r1,#0x14]
+    str     r0, [r1,#0x14]          // TODO: This is not done by s5l8720, and I don't think it's necessary for s5l8702
     str     r0, [r2,#0x14]
 
 #if defined(BOOTLOADER)