Wolfgang Denk | adf20a1 | 2005-09-25 01:48:28 +0200 | [diff] [blame] | 1 | |
| 2 | U-Boot for ARM Integrator Development Platforms |
| 3 | |
| 4 | Peter Pearse, ARM Ltd. |
| 5 | peter.pearse@arm.com |
| 6 | www.arm.com |
| 7 | |
| 8 | Manuals available from :- |
| 9 | http://www.arm.com/products/DevTools/Hardware_Platforms.html |
| 10 | |
| 11 | Overview : |
| 12 | -------- |
| 13 | There are two Integrator variants - Integrator/AP and Integrator/CP. |
| 14 | Each may be fitted with a variety of core modules (CMs). |
Wolfgang Denk | c856ccc | 2005-09-25 02:00:47 +0200 | [diff] [blame] | 15 | Each CM consists of a ARM processor core and associated hardware e.g |
Wolfgang Denk | adf20a1 | 2005-09-25 01:48:28 +0200 | [diff] [blame] | 16 | FPGA implementing various controllers and/or register |
| 17 | SSRAM |
| 18 | SDRAM |
| 19 | RAM controllers |
| 20 | clock generators etc. |
Wolfgang Denk | 03f9ba3 | 2005-10-04 23:10:28 +0200 | [diff] [blame] | 21 | CMs may be fitted with varying amounts of SDRAM using a DIMM socket. |
Wolfgang Denk | adf20a1 | 2005-09-25 01:48:28 +0200 | [diff] [blame] | 22 | |
| 23 | Boot Methods : |
| 24 | ------------ |
| 25 | Integrator platforms can be configured to use U-Boot in at least three ways :- |
| 26 | a) Run ARM boot monitor, manually run U-Boot image from flash |
| 27 | b) Run ARM boot monitor, automatically run U-Boot image from flash |
| 28 | c) Run U-Boot image direct from flash. |
| 29 | |
Wolfgang Denk | c856ccc | 2005-09-25 02:00:47 +0200 | [diff] [blame] | 30 | In cases a) and b) the ARM boot monitor will have configured the CM and mapped |
Wolfgang Denk | adf20a1 | 2005-09-25 01:48:28 +0200 | [diff] [blame] | 31 | writeable memory to 0x00000000 in the Integrator address space. |
| 32 | U-Boot has to carry out minimal configration before standard code is run. |
| 33 | |
| 34 | In case c) it may be necessary for U-Boot to perform CM dependent initialization. |
| 35 | |
| 36 | Configuring U-Boot : |
Wolfgang Denk | c856ccc | 2005-09-25 02:00:47 +0200 | [diff] [blame] | 37 | ------------------ |
Wolfgang Denk | adf20a1 | 2005-09-25 01:48:28 +0200 | [diff] [blame] | 38 | The makefile contains targets for Integrator platforms of both types |
Wolfgang Denk | c856ccc | 2005-09-25 02:00:47 +0200 | [diff] [blame] | 39 | fitted with all current variants of CM. If these targets are to be used with |
| 40 | boot process c) above then CONFIG_INIT_CRITICAL may need to be defined to ensure |
Wolfgang Denk | adf20a1 | 2005-09-25 01:48:28 +0200 | [diff] [blame] | 41 | that the CM is correctly configured. |
| 42 | |
| 43 | There are also targets independent of CM. These may not be suitable for |
Wolfgang Denk | c856ccc | 2005-09-25 02:00:47 +0200 | [diff] [blame] | 44 | boot process c) above. They have been preserved for backward compatibility with |
Wolfgang Denk | adf20a1 | 2005-09-25 01:48:28 +0200 | [diff] [blame] | 45 | existing build processes. |
| 46 | |
| 47 | Code Hierarchy Applied : |
| 48 | ---------------------- |
Wolfgang Denk | c856ccc | 2005-09-25 02:00:47 +0200 | [diff] [blame] | 49 | Code specific to initialization of a particular ARM processor has been placed in |
Wolfgang Denk | adf20a1 | 2005-09-25 01:48:28 +0200 | [diff] [blame] | 50 | cpu/arm<>/start.S so that it may be used by other boards. |
| 51 | |
Wolfgang Denk | c856ccc | 2005-09-25 02:00:47 +0200 | [diff] [blame] | 52 | However, to avoid duplicating code through all processor files, a generic core |
Wolfgang Denk | adf20a1 | 2005-09-25 01:48:28 +0200 | [diff] [blame] | 53 | for ARM Integrator CMs has been added |
| 54 | |
| 55 | cpu/arm_intcm |
| 56 | |
| 57 | Otherwise. for example, the standard CM reset via the CM control register would |
| 58 | need placing in each CM processor file...... |
| 59 | |
| 60 | Code specific to the initialization of the CM, rather than the cpu, and initialization |
Wolfgang Denk | c856ccc | 2005-09-25 02:00:47 +0200 | [diff] [blame] | 61 | of the Integrator board itself, has been placed in |
Wolfgang Denk | adf20a1 | 2005-09-25 01:48:28 +0200 | [diff] [blame] | 62 | |
Wolfgang Denk | c856ccc | 2005-09-25 02:00:47 +0200 | [diff] [blame] | 63 | board/integrator<>/platform.S |
Wolfgang Denk | adf20a1 | 2005-09-25 01:48:28 +0200 | [diff] [blame] | 64 | board/integrator<>/integrator<>.c |